Abiogenesis and directed panspermia again

[pnyikos]

A theme that has occupied me on and off ever since I resumed posting
to talk.origins in December 2010 is the probability of earth life
having arisen from abiogenesis on earth as opposed to having been
brought (or sent) here from another solar system by a spacefaring
species that lived ca. 4 billion years ago.

The latest revival is on the thread with "Intelligent Design Book
Meets Obstacle" in the subject line, with John Harshman the main
person debating with me on it.

Here, before we get too bogged down in minutiae, is a reply to John's
latest post on this fascinating topic. Another reply will be made on
the original thread--it's a long post, too long for a single reply.

On May 29, 9:39 am, John Harshman <jharsh...@pacbell.net> wrote:
> pnyikos wrote:
> > On May 28, 8:03 pm, John Harshman <jharsh...@pacbell.net> wrote:
> >> pnyikos wrote:
> >>> On May 28, 9:54 am, John Harshman <jharsh...@pacbell.net> wrote:
> >>> Let's see: what would constitute an argument in your eyes?
> >>> 1. Nailing down actual figures, as in "I hypothesize that
> >>> (a) .00004 of all the planets where prokaryote-level organisms arise
> >>> result in an intelligent species and of those,
>
> > That's one in 25,000 seeded planets going on to intelligent species.
> >>> (b) half go on to a level of technology capable of interstellar
> >>> communication; of those,
>
> > So one in 50,000 going on to 21st century human level.
>
> >>> (c) half come to discover that they are alone in the observable part
> >>> of the galaxy and possibly of the universe; and of those
>
> >>> (d) one-fourth, on the average, undertake a panspermia project that
> >>> seeds at least a million planets with prokaryote or higher level
> >>> organisms."?
>
> > So one in 8 species coming to 21st century human level seed one
> > million planets apiece. So these fruitful species are each, on the
> > average, responsible for 20 first-generation 21st century human level
> > species. Dividing by 8 gives 2.5 intelligent species resulting from
> > directed panspermia for every one resulting from homegrown
> > abiogenesis.
>
> ....If there is any seeding at all. But by far the highest probability is
> that there is none. You have computed the probability that, if someone
> seeded the local area before us, we are not those people.

False.

> It seems to me
> that you have shown that the probability is higher that nobody seeded
> anything.

I'd like to see your reasoning, if any, for this counterintuitive
claim.

> >>> So done. There: I've given you a stationary target to ask questions
> >>> about and raise objections to.
> >> That's certainly close to an argument. But it's incomplete. What are we
> >> assuming about the initial life that "arises"?
>
> > "arises" wasn't the best choice of words, I see: I should have said,
> > "comes to be on a planet favorable for subsequent evolution". It
> > could happen one of three natural [as opposed to supernatural ways]:
> > homegrown abiogenesis, undirected panspermia, or placement by
> > intelligent creatures that arose elsewhere.
>
> > For the *initial* life form -- that one in a galaxy/universe
> > happenstance according to my hypothesis, it would be via homegrown
> > abiogenesis, although a lot of ingredients for it might have come from
> > elsewhere.
>
> > I'm not making any assumptions as to the biological makeup of any
> > intelligent creatures, including the hypothesized panspermists. But
> > for the sake of focused discussion, I've formulated four sub-
> > hypotheses as to their biochemical makeup:
>
> > 1. The "Xordaxian" hypothesis: very similar to ours, including a
> > genetic code close to identical to ours.
>
> > 2. The "Golian" hypothesis: also very similar, except their genetic
> > code involved fewer amino acids, perhaps as few as four.
>
> > 3. The "Throomian" hypothesis: ribozyme enzymes, proteins relatively
> > simple and mostly structural.
>
> > 4. The "para-3M" hypothesis: life as we do NOT know it, made up of
> > far simpler cells whose structure we cannot at this point even
> > imagine, but whose progenotic precursors were highly likely to exist
> > given pre-biotic conditions like those on the early earth.
>
> Each of these should produce a different probability calculation, so you
> have to specify.

Only in the sense that we are currently in the dark as to the
difficulty of producing intelligent life forms in categories 2, 3, and
4, and so those 1 in 25,000, etc. odds are less well grounded. Beyond
that, I don't see the relevance. Perhaps you can explain something
I'm missing out on here.

We are given that we are here, and that we evolved from prokaryotes.
As to whether those prokaryotes are due to minimal or no genetic
modification -- something neither you nor Meyer would count as
designing "a whole organism" -- as in the Xordaxian hypothesis, or
something both of you would call that, as in the para-3M hypothesis,
hardly seems relevant to the probabilities.

> But as far as I can see, only #1 makes any sense. Why
> should an intelligent species engineer life very unlike themselves?

A. Diversifying one's "sendings" so that if one is not well adapted to
the environment, another might be;
B. Diversifying the outcome. I did a long reply to Robert Camp, who
seems to have quit this "Intelligent Design" thread, touching on
this theme at length back in December 2010:

http://groups.google.com/group/talk.origins/msg/44a5c533d7f0c9f6

C. Speeding up the outcome, by starting with a more adaptable
organism. This is especially easier to see in comparing our
biochemistry with the Golian.

>They
> know that their sort of life worked, and achieved their goal of evolving
> into an intelligent species. Why mess with success?

Why would setting things in motion for another intelligent species
billions of years in the future be "messing with success"? You are
unusually hard to follow in this post, John.

[snip something to be dealt with on the original thread]

> >> Certainly that ought to
> >> change the probabilities somewhat. If we suppose that life to be similar
> >> to what we have on earth, that's one thing. If it's your RNA-based life,
> >> that's another thing.
>
> > I don't think the differences between various sub-hypotheses is a
> > profitable angle to pursue at this point. I do believe the "para-3M"
> > hypothesis entails that "prokaryote-level" be a multicellular rather
> > than a unicellular stage, otherwise the odds against it evolving to an
> > intelligent life form is considerably reduced.
>
> How can you possibly suppose that, given that you say you know nothing
> about them?

Their extreme simplicity, dictated by the fact that they are
supposedly very likely on a planet as favorable towards life as the
earth. For that to be true, they couldn't be much more complicated
than Ian Musgrave's HypUrCell:

http://www.talkorigins.org/faqs/abioprob/abioprob.html

> And how can you equate stages in completely alien forms?

I'm working on that (and much else relevant to this sub-thread) now in
a sci.bio.evolution thread, "Expanding the Drake Equation." You can
either wait until the thread seems spent, or join me there.

> > Of course, if someone [perhaps Mitchell, or Michael, or Mark] wants to
> > argue otherwise, I'm willing to listen.
>
> It makes a huge difference for you, since the probability of life
> supposedly increases as we go from 1 to 4,

Yes, but the probability of intelligent life is a huge unknown there,
as I've noted above. It stands to reason that there is a trade-off,
the comparatively easier abiogenesis leading to a steeper climb to
achieve intelligence. Golian life is obviously less diverse and
adaptable than Xordaxian, for example.

> and is apparently high for
> option 4. Now perhaps the probability of intelligence becomes lower as
> we go from 1 to 4, and all that balances out. But don't you have to
> think about it?

I've thought about it since before my December 2010 return, without
coming to any conclusions as to how the trade-off works, except for
what I've said just now.

Peter Nyikos
Professor, Dept. of Mathematics -- standard disclaimer--
University of South Carolina
http://www.math.sc.edu/~nyikos/
nyikos @ math.sc.edu

[prawnster]

> nyikos @ math.sc.edu- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -

Speculation.

Fantasy.

And ultimately:

Punt!

[pnyikos]

In the old Google Groups, which I am still using [is it the same in
the new GG?] a lot of earlier information got hidden behind blue "Show
quoted text" buttons, so for the convenience of readers I am reposting
it in this piggyback on "prawnster"s clueless post, which I address at
the end.

On May 30, 6:05 am, prawnster <zweibro...@ymail.com> wrote:
> On May 29, 6:01 pm, pnyikos <nyik...@bellsouth.net> wrote:
> > On May 29, 9:39 am, John Harshman <jharsh...@pacbell.net> wrote:
>
> > > pnyikos wrote:
> > > > On May 28, 8:03 pm, John Harshman <jharsh...@pacbell.net> wrote:
> > > >> pnyikos wrote:

I hypothesize that

(a) .00004 of all the planets where prokaryote-level organisms arise
result in an intelligent species and of those,

(b) half go on to a level of technology capable of interstellar
communication; of those,

(c) half come to discover that they are alone in the observable part
of the galaxy and possibly of the universe; and of those

(d) one-fourth, on the average, undertake a panspermia project that
seeds at least a million planets with prokaryote or higher level
organisms.

<snip>

I'm not making any assumptions as to the biological makeup of any
intelligent creatures, including the hypothesized panspermists. But
for the sake of focused discussion, I've formulated four sub-
hypotheses as to their biochemical makeup:


1. The "Xordaxian" hypothesis: very similar to ours, including a
genetic code close to identical to ours.


2. The "Golian" hypothesis: also very similar, except their genetic
code involved fewer amino acids, perhaps as few as four.


3. The "Throomian" hypothesis: ribozyme enzymes, proteins relatively
simple and mostly structural.


4. The "para-3M" hypothesis: life as we do NOT know it, made up of
far simpler cells whose structure we cannot at this point even
imagine, but whose progenotic precursors were highly likely to exist
given pre-biotic conditions like those on the early earth.


> > > Each of these should produce a different probability calculation, so you
> > > have to specify.
>
> > Only in the sense that we are currently in the dark as to the
> > difficulty of producing intelligent life forms in categories 2, 3, and
> > 4, and so those 1 in 25,000, etc. odds are less well grounded. Beyond
> > that, I don't see the relevance.  Perhaps you can explain something
> > I'm missing out on here.

<snip>

> > > But as far as I can see, only #1 makes any sense. Why
> > > should an intelligent species engineer life very unlike themselves?
>
> > A. Diversifying one's "sendings" so that if one is not well adapted to
> > the environment, another might be;
> > B. Diversifying the outcome.  I did a long reply to Robert Camp, who
> > seems to have quit this "Intelligent Design"  thread, touching  on
> > this theme at length back in December 2010:
>
> >http://groups.google.com/group/talk.origins/msg/44a5c533d7f0c9f6
>
> > C. Speeding up the outcome, by starting with a more adaptable
> > organism.  This is especially easier to see in comparing our
> > biochemistry with the Golian.

<snip>

> > > And how can you equate stages in completely alien forms?
>
> > I'm working on that (and much else relevant to this sub-thread) now in
> > a sci.bio.evolution thread, "Expanding the Drake Equation."  You can
> > either wait until the thread seems spent, or join me there.

And now we come to prawnster:

> Speculation.

No more so than the speculation that earth life originated with
abiogenesis *on* *earth*.

> Fantasy.

This is the *real* fantasy:

Mother Earth did it, this I know
For Ockham's Razor tells me so.

Do you subscribe to this mantra?

> And ultimately:
>
> Punt!

Looks like the answer to my question is "Yes". :-)

Peter Nyikos

[prawnster]

On May 30, 5:06 am, pnyikos <nyik...@bellsouth.net> wrote:
> [...]

> > Speculation.
>
> No more so than the speculation that earth life originated with
> abiogenesis *on* *earth*.
>
> > Fantasy.
>
> This is the *real* fantasy:
>
>    Mother Earth did it, this I know
>    For Ockham's Razor tells me so.
>
> Do you subscribe to this mantra?
>
> > And ultimately:
>
> > Punt!
>
> Looks like the answer to my question is "Yes".   :-)
>

Yes, Earthly abiogenesis is pure phantastical speculation at this
point.

No, I don't subscribe to that mantra. My mantra is Goddidit, this I
know, because the Bible tells me so. And no one has provided any
evidence superior to that explanation.

And no, the answer to your question is "Let's assert that panspermia
happened and thus punt on the larger question about who created the
beings who created us." Panspermia as an answer for the origins of
life creates more questions than it answers; it's pure Macco's Rozar.

[pnyikos]

On May 30, 8:30 am, prawnster <zweibro...@ymail.com> wrote:
> On May 30, 5:06 am, pnyikos <nyik...@bellsouth.net> wrote:
>
>
>
>
>
> > [...]
> > > Speculation.
>
> > No more so than the speculation that earth life originated with
> > abiogenesis *on* *earth*.
>
> > > Fantasy.
>
> > This is the *real* fantasy:
>
> >    Mother Earth did it, this I know
> >    For Ockham's Razor tells me so.
>
> > Do you subscribe to this mantra?
>
> > > And ultimately:
>
> > > Punt!
>
> > Looks like the answer to my question is "Yes".   :-)
>
> Yes, Earthly abiogenesis is pure phantastical speculation at this
> point.

> No, I don't subscribe to that mantra.  My mantra is Goddidit, this I
> know, because the Bible tells me so.  And no one has provided any
> evidence superior to that explanation.

Ah. I see you are of the Ray Martinez types, who does not extrapolate
from C. S. Lewis's _Out of the Silent Planet_ and _Perelandra_ to the
possibility that God might have inspired panspermists to spread life
far and wide ca. 4 billion years ago, just as he inspired Noah to save
a huge boatload of animals so they could be fruitful, multiply, and
replenish the earth.

Don't forget, Genesis 1 has God saying, "Let the earth bring forth
plants..." It doesn't say, "God created plants..."

> And no, the answer to your question is "Let's assert that panspermia
> happened and thus punt on the larger question about who created the
> beings who created us."

You mean move it one step back, meanwhile giving food for thought for
those who automatically think abiogenesis is common all through the
universe. I personally think it is a once-in-a-universe fluke,
barring supernatural intervention.

> Panspermia as an answer for the origins of
> life creates more questions than it answers;

That's what makes it so attractive for me. I've found out all kinds
of neat things while thinking about the steps from prokaryotes to
higher forms of life. For instance, just the other day I found out
that the surface gravity of Titan is 0.14g -- less than that of our
moon! And yet its atmosphere is about 1.5 times as dense as that of
earth!!

Just think of the possiblity of intelligent fliers, the size of
humans!

>it's pure Macco's Rozar.-

Wrong.

Peter Nyikos

[John Harshman]

Well, that settles things, then.

>> It seems to me
>> that you have shown that the probability is higher that nobody seeded
>> anything.
>
> I'd like to see your reasoning, if any, for this counterintuitive
> claim.

Why is it counterintuitive? Again, you begin with the assumption that
there is a prior intelligent species on some other planet. Why are you
allowed that assumption?

You need to consider both the probability of life arising, in each
scenario, and the probability of that life giving rise to intelligence.
Now of course currently you just assume that it happened, which is why
you don't see the relevance. But I'm claiming you can't make such an
assumption.

> We are given that we are here, and that we evolved from prokaryotes.
> As to whether those prokaryotes are due to minimal or no genetic
> modification -- something neither you nor Meyer would count as
> designing "a whole organism" -- as in the Xordaxian hypothesis, or
> something both of you would call that, as in the para-3M hypothesis,
> hardly seems relevant to the probabilities.

Only if you begin with the assumption that some prior intelligence
seeded planets with prokaryotes. You have to include the probabilities
of such a prior intelligence existing, or you're assuming most of your
conclusion.

>> But as far as I can see, only #1 makes any sense. Why
>> should an intelligent species engineer life very unlike themselves?
>
> A. Diversifying one's "sendings" so that if one is not well adapted to
> the environment, another might be;

A normal intelligence would do that by sending different sorts of
prokaryotes, with different adaptations. Not by inventing a whole new
sort of life.

> B. Diversifying the outcome. I did a long reply to Robert Camp, who
> seems to have quit this "Intelligent Design" thread, touching on
> this theme at length back in December 2010:
>
> http://groups.google.com/group/talk.origins/msg/44a5c533d7f0c9f6
>
> C. Speeding up the outcome, by starting with a more adaptable
> organism. This is especially easier to see in comparing our
> biochemistry with the Golian.

This is really only a mechanism that allows you to postulate radically
different life forms for the seeders yet end up with our sort of life in
the seeded. These "justifications" are just special pleading.

Out of curiosity, would you consider it worthwhile for us to populate
the galaxy with von Neumann machines? Arguably they're much better
suited for the job than any organic life, and we could probably add some
evolutionary mechanisms to their makeup.

>> They
>> know that their sort of life worked, and achieved their goal of evolving
>> into an intelligent species. Why mess with success?
>
> Why would setting things in motion for another intelligent species
> billions of years in the future be "messing with success"? You are
> unusually hard to follow in this post, John.

Why, if intelligence was their goal, would they abandon the only sort of
life known to have produced intelligence (theirs) in favor of a
completely untested alternative?

> [snip something to be dealt with on the original thread]
>
>>>> Certainly that ought to
>>>> change the probabilities somewhat. If we suppose that life to be similar
>>>> to what we have on earth, that's one thing. If it's your RNA-based life,
>>>> that's another thing.
>>> I don't think the differences between various sub-hypotheses is a
>>> profitable angle to pursue at this point. I do believe the "para-3M"
>>> hypothesis entails that "prokaryote-level" be a multicellular rather
>>> than a unicellular stage, otherwise the odds against it evolving to an
>>> intelligent life form is considerably reduced.
>> How can you possibly suppose that, given that you say you know nothing
>> about them?
>
> Their extreme simplicity, dictated by the fact that they are
> supposedly very likely on a planet as favorable towards life as the
> earth. For that to be true, they couldn't be much more complicated
> than Ian Musgrave's HypUrCell:
>
> http://www.talkorigins.org/faqs/abioprob/abioprob.html

So how does that affect the probability of them existing at all, which
ought to be crucial to your calculations?

>> And how can you equate stages in completely alien forms?
>
> I'm working on that (and much else relevant to this sub-thread) now in
> a sci.bio.evolution thread, "Expanding the Drake Equation." You can
> either wait until the thread seems spent, or join me there.

I'll wait here.

>>> Of course, if someone [perhaps Mitchell, or Michael, or Mark] wants to
>>> argue otherwise, I'm willing to listen.
>> It makes a huge difference for you, since the probability of life
>> supposedly increases as we go from 1 to 4,
>
> Yes, but the probability of intelligent life is a huge unknown there,
> as I've noted above. It stands to reason that there is a trade-off,
> the comparatively easier abiogenesis leading to a steeper climb to
> achieve intelligence. Golian life is obviously less diverse and
> adaptable than Xordaxian, for example.

I don't see that as being obvious. But even if there's a tradeoff,
you're assuming that the tradeoffs cancel out. And if they cancel out,
what reason can there be for your aliens to try radically different life?

>> and is apparently high for
>> option 4. Now perhaps the probability of intelligence becomes lower as
>> we go from 1 to 4, and all that balances out. But don't you have to
>> think about it?
>
> I've thought about it since before my December 2010 return, without
> coming to any conclusions as to how the trade-off works, except for
> what I've said just now.

Then your argument and your probability estimates are missing crucial
features, wouldn't you agree?

[prawnster]

On May 30, 6:03 am, pnyikos <nyik...@bellsouth.net> wrote:
> [...]

> That's what makes it so attractive for me.  I've found out all kinds
> of neat things while thinking about the steps from prokaryotes to
> higher forms of life.  For instance, just the other day I found out
> that the surface gravity of Titan is 0.14g -- less than that of our
> moon!  And yet its atmosphere is about 1.5 times as dense as that of
> earth!!
>
> Just think of the possiblity of intelligent fliers, the size of
> humans!
>

Yes, thinking about the steps from little critters to bigger critters
is, apparently, fun for a lot of people. But it's not science.

Earth already has intelligent fliers: they're called birds. And who
cares about Titan? Titan is a wasteland. Other than Earth, the
entire Solar system sucks gallon after gallon of ape chode.

[Walter Bushell]

In article <4d-dnUoRc7j...@giganews.com>,

John Harshman <jhar...@pacbell.net> wrote:

>
> Why, if intelligence was their goal, would they abandon the only sort of
> life known to have produced intelligence (theirs) in favor of a
> completely untested alternative?

I like Larry Niven's fictional take, we are all descended from food
yeast that has gone bad.

--
This space unintentionally left blank.

[Mark Isaak]

On 5/30/12 6:03 AM, pnyikos wrote:
> On May 30, 8:30 am, prawnster<zweibro...@ymail.com> wrote:

> [...]

>> No, I don't subscribe to that mantra. My mantra is Goddidit, this I
>> know, because the Bible tells me so. And no one has provided any
>> evidence superior to that explanation.
>
> Ah. I see you are of the Ray Martinez types, who does not extrapolate
> from C. S. Lewis's _Out of the Silent Planet_ and _Perelandra_ to the
> possibility that God might have inspired panspermists to spread life
> far and wide ca. 4 billion years ago, just as he inspired Noah to save
> a huge boatload of animals so they could be fruitful, multiply, and
> replenish the earth.

You do Ray a grave disservice by comparing him to prawnster.
Prawnster's purpose on talk.origins is to make Ray and Dale look
entirely rational, Suzanne look intelligent, Mr. Dunsapy and Alan
Kleinman look open-minded, and Nando look kind-hearted by comparison.
By and large, he succeeds.

--
Mark Isaak eciton (at) curioustaxonomy (dot) net
"It is certain, from experience, that the smallest grain of natural
honesty and benevolence has more effect on men's conduct, than the most
pompous views suggested by theological theories and systems." - D. Hume

[Friar Broccoli]

Could you check your spam box for an email I sent you two days ago
(Monday evening).

--
Friar Broccoli (Robert Keith Elias), Quebec Canada
I consider ALL arguments in support of my views

[John Harshman]

Walter Bushell wrote:
> In article <4d-dnUoRc7j...@giganews.com>,
> John Harshman <jhar...@pacbell.net> wrote:
>
>> Why, if intelligence was their goal, would they abandon the only sort of
>> life known to have produced intelligence (theirs) in favor of a
>> completely untested alternative?
>
> I like Larry Niven's fictional take, we are all descended from food
> yeast that has gone bad.
>

Mind you, that only happened a couple of billion years ago, so the
prokaryotes would have to be home-grown. The thrints found a nice planet
full of prokaryotes, stuck in a few eukaryotes to feed on them, and let
it go. But why no bandersnatch?

[chris thompson]

On May 30, 3:52 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>
wrote:

> On 5/30/12 6:03 AM, pnyikos wrote:
>
> > On May 30, 8:30 am, prawnster<zweibro...@ymail.com>  wrote:
> > [...]
> >> No, I don't subscribe to that mantra.  My mantra is Goddidit, this I
> >> know, because the Bible tells me so.  And no one has provided any
> >> evidence superior to that explanation.
>
> > Ah.  I see you are of the Ray Martinez types, who does not extrapolate
> > from C. S. Lewis's _Out of the Silent Planet_ and _Perelandra_ to the
> > possibility that God might have inspired panspermists to spread life
> > far and wide ca. 4 billion years ago, just as he inspired Noah to save
> > a huge boatload of animals so they could be fruitful, multiply, and
> > replenish the earth.
>
> You do Ray a grave disservice by comparing him to prawnster.
> Prawnster's purpose on talk.origins is to make Ray and Dale look
> entirely rational, Suzanne look intelligent, Mr. Dunsapy and Alan
> Kleinman look open-minded, and Nando look kind-hearted by comparison.
> By and large, he succeeds.

It's been quite a while since we had someone of Prawnster's caliber on
t.o. I'm not sure it's a good thing, but he was amusing for a little
while.

Chris

PS: I am not sure anyone can make Dr.Dr. K. look open-minded. He
sounds like a badly designed Turning Test.

[pnyikos]

On May 30, 12:23 pm, prawnster <zweibro...@ymail.com> wrote:
> On May 30, 6:03 am, pnyikos <nyik...@bellsouth.net> wrote:

You deleted some things I said about C.S Lewis's books from his space
trilogy. Have you ever read them? If not, _Out of the Silent Planet_
should be a real treat for you.

> > [...]
> > That's what makes it so attractive for me.  I've found out all kinds
> > of neat things while thinking about the steps from prokaryotes to
> > higher forms of life.  For instance, just the other day I found out
> > that the surface gravity of Titan is 0.14g -- less than that of our
> > moon!  And yet its atmosphere is about 1.5 times as dense as that of
> > earth!!
>
> > Just think of the possiblity of intelligent fliers, the size of
> > humans!
>
> Yes, thinking about the steps from little critters to bigger critters
> is, apparently, fun for a lot of people.  But it's not science.

So you allege. And how about bigger critters to little critters, like
wolves (or jackals) to chihuahuas?

> Earth already has intelligent fliers: they're called birds.

I mean REALLY intelligent, like humans, with sophisticated languages
enabling them to express any everyday happening, and then some.

>  And who
> cares about Titan?  Titan is a wasteland.  Other than Earth, the
> entire Solar system sucks gallon after gallon of ape chode.

I was thinking of other solar systems, where a Titan-sized planet
might be in the "Goldilocks zone" like earth is now, and be the abode
of oxygen-breathing creatures like ourselves, only looking like angels
-- or devils -- and of roughly the same level of intelligence.

[pnyikos]

On May 30, 3:43 pm, Walter Bushell <pr...@panix.com> wrote:
> In article <4d-dnUoRc7jgplvS4p2d...@giganews.com>,

>  John Harshman <jharsh...@pacbell.net> wrote:
>
>
>
> > Why, if intelligence was their goal, would they abandon the only sort of
> > life known to have produced intelligence (theirs) in favor of a
> > completely untested alternative?

I dunno why John said "abandon". Perhaps he hasn't gotten around to
reading my second reply, on the other thread, where I wrote:

[quote, beginning with John's words:]

>They
> know that their sort of life worked, and achieved their goal of evolving
> into an intelligent species. Why mess with success?

They could have sent several kinds, their own and the modified as
well. Perhaps even the Xordaxians did that, only their kind of
biochemistry triumphed in the early earth.
[end of quote]

> I like Larry Niven's fictional take, we are all descended from food
> yeast that has gone bad.

That's a slight improvement on the "space garbage" hypothesis of the
1960's as far as the "yuck [spelled "yecch" back then] factor" goes,
but not much. Where does he have the food yeast originating?

Peter Nyikos

[pnyikos]

On May 30, 3:52 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>
wrote:

> On 5/30/12 6:03 AM, pnyikos wrote:
>
> > On May 30, 8:30 am, prawnster<zweibro...@ymail.com>  wrote:
> > [...]
> >> No, I don't subscribe to that mantra.  My mantra is Goddidit, this I
> >> know, because the Bible tells me so.  And no one has provided any
> >> evidence superior to that explanation.
>
> > Ah.  I see you are of the Ray Martinez types, who does not extrapolate
> > from C. S. Lewis's _Out of the Silent Planet_ and _Perelandra_ to the
> > possibility that God might have inspired panspermists to spread life
> > far and wide ca. 4 billion years ago, just as he inspired Noah to save
> > a huge boatload of animals so they could be fruitful, multiply, and
> > replenish the earth.
>
> You do Ray a grave disservice by comparing him to prawnster.

Well, I haven't seen enough of prawnster yet to comment on that.

> Prawnster's purpose on talk.origins is to make Ray and Dale look
> entirely rational, Suzanne look intelligent, Mr. Dunsapy and Alan
> Kleinman look open-minded, and Nando look kind-hearted by comparison.
> By and large, he succeeds.

How would you compare him to "vowel boy"?

And, have you ever looked at Wretch Fossil's posts, over in
sci.bio.paleontology? I don't know which is more annoying, his kooky
ideas about human blood in Mars meteorites and his conviction that the
moon landings were faked, or ordinary spam. He's also arrogant, and
thinks God the creator died a few decades ago and now God is a human
being who lives in China

Peter Nyikos

[pnyikos]

The probability for that is given above. You have not tried to
dispute it. You have, instead, falsely claimed below that I am
assuming that it happened already, in the past, in THIS galaxy. That
is not an assumption, it is a cautious conclusion that the odds favor
it.

Note that the above probability has to do with all galaxies, in all
universes like ours in every essential respect.

> > > But by far the highest probability is
> >> that there is none. You have computed the probability that, if someone
> >> seeded the local area before us, we are not those people.

The "before us" makes the probability 1. I never mentioned any such
probability, let alone computed it.

> > False.
>
> Well, that settles things, then.

Yes, and I think this time even you can see it. Do you still cling to
the "backpedal" you did below?

> >> It seems to me
> >> that you have shown that the probability is higher that nobody seeded
> >> anything.
>
> > I'd like to see your reasoning, if any, for this counterintuitive
> > claim.

> Why is it counterintuitive?

Because I never said anything even remotely resembling it.

>Again, you begin with the assumption that
> there is a prior intelligent species on some other planet.

Bizarre, this imputing of assumptions to me that I never made. And my
clarification of the word "arises" below should have dispelled any
thought in your mind that I made this one. Why do you cling to it?

> >>>>> So done.  There: I've given you a stationary target to ask questions
> >>>>> about and raise objections to.
> >>>> That's certainly close to an argument. But it's incomplete. What are we
> >>>> assuming about the initial life that "arises"?

See, I talk about all three possibilities below.

> >>> "arises" wasn't the best choice of words, I see: I should have said,
> >>> "comes to be on a planet favorable for subsequent evolution".  It
> >>> could happen one of three natural [as opposed to supernatural ways]:
> >>> homegrown abiogenesis, undirected panspermia, or placement by
> >>> intelligent creatures that arose elsewhere.
> >>> For the *initial* life form -- that one in a galaxy/universe
> >>> happenstance according to my hypothesis, it would be via homegrown
> >>> abiogenesis, although a lot of ingredients for it might have come from
> >>> elsewhere.

That's initial life, whether it goes on to produce creatures like
ourselves, or not. Next I focus on the intelligent ones, and then
narrow the focus further, after first making a general statement:

> >>> I'm not making any assumptions as to the biological makeup of any
> >>> intelligent creatures, including the hypothesized panspermists.

They are the *conclusion* of my reasoning, and not my initial
assumption.

> >>> But
> >>> for the sake of focused discussion, I've formulated four sub-
> >>> hypotheses as to their biochemical makeup:
> >>> 1.  The "Xordaxian" hypothesis: very similar to ours, including a
> >>> genetic code close to identical to ours.
> >>> 2.  The "Golian" hypothesis: also very similar, except their genetic
> >>> code involved fewer amino acids, perhaps as few as four.
> >>> 3.  The "Throomian" hypothesis: ribozyme enzymes, proteins relatively
> >>> simple and mostly structural.
> >>> 4. The "para-3M" hypothesis:  life as we do NOT know it, made up of
> >>> far simpler cells whose structure we cannot at this point even
> >>> imagine, but whose progenotic precursors were highly likely to exist
> >>> given pre-biotic conditions like those on the early earth.
> >> Each of these should produce a different probability calculation, so you
> >> have to specify.
>
> > Only in the sense that we are currently in the dark as to the
> > difficulty of producing intelligent life forms in categories 2, 3, and
> > 4, and so those 1 in 25,000, etc. odds are less well grounded. Beyond
> > that, I don't see the relevance.  Perhaps you can explain something
> > I'm missing out on here.
>
> You need to consider both the probability of life arising, in each
> scenario, and the probability of that life giving rise to intelligence.

These two lines are essentially a repetition of the previous two. You
don't explain the reason for them, you just go back to your earlier
allegation--again without explaining it:

> Now of course currently you just assume that it happened, which is why
> you don't see the relevance. But I'm claiming you can't make such an
> assumption.
.
> >  We are given that we are here, and that we evolved from prokaryotes.
> > As to whether those prokaryotes are due to minimal or no genetic
> > modification -- something neither you nor Meyer would count as
> > designing "a whole  organism" -- as in the Xordaxian hypothesis, or
> > something both of you would call that, as in the para-3M hypothesis,
> > hardly seems relevant to the probabilities.

[yet another repetition deleted here]

So shoot me for not adding, "if they were seeded here" after the
second "prokaryotes". Will you also accuse me of being a theist if I
ever leave out "if there is a God" whenever I use the word "God"?

Continued in next reply.

Peter Nyikos

[pnyikos]

On May 30, 11:23 am, John Harshman <jharsh...@pacbell.net> wrote:
> pnyikos wrote:
> > On May 29, 9:39 am, John Harshman <jharsh...@pacbell.net> wrote:
> >> pnyikos wrote:

I pick up where I left off in my first reply, after repeating the
description of four sub-hypotheses of my directed panspermia
hypothesis.

> >>> for the sake of focused discussion, I've formulated four sub-
> >>> hypotheses as to their biochemical makeup:
> >>> 1. The "Xordaxian" hypothesis: very similar to ours, including a
> >>> genetic code close to identical to ours.
> >>> 2. The "Golian" hypothesis: also very similar, except their genetic
> >>> code involved fewer amino acids, perhaps as few as four.
> >>> 3. The "Throomian" hypothesis: ribozyme enzymes, proteins relatively
> >>> simple and mostly structural.
> >>> 4. The "para-3M" hypothesis: life as we do NOT know it, made up of
> >>> far simpler cells whose structure we cannot at this point even
> >>> imagine, but whose progenotic precursors were highly likely to exist
> >>> given pre-biotic conditions like those on the early earth.

> >> But as far as I can see, only #1 makes any sense. Why
> >> should an intelligent species engineer life very unlike themselves?
>
> > A. Diversifying one's "sendings" so that if one is not well adapted to
> > the environment, another might be;
>
> A normal intelligence would do that by sending different sorts of
> prokaryotes, with different adaptations. Not by inventing a whole new
> sort of life.

I submit that you are incompetent to make such sweeping claims about
what a normal intelligence would do. Especially since you dismissed
a reply by me to Camp of which I write next, on the grounds that I was
speculating that aliens would think in anything like a human way.

> > B. Diversifying the outcome. I did a long reply to Robert Camp, who
> > seems to have quit this "Intelligent Design" thread, touching on
> > this theme at length back in December 2010:
>
> >http://groups.google.com/group/talk.origins/msg/44a5c533d7f0c9f6

You might do well to click on that link and read it, in the light of
your formulaic words below.

> > C. Speeding up the outcome, by starting with a more adaptable
> > organism. This is especially easier to see in comparing our
> > biochemistry with the Golian.
>
> This is really only a mechanism that allows you to postulate radically
> different life forms for the seeders yet end up with our sort of life in
> the seeded. These "justifications" are just special pleading.

This formulaic response could be applied, with obvious changes in
wording, to any attempt by anyone to give alternative explanations
for anything. If this is the way your mental apparatus works, it's no
wonder you made no attempt to justify any of your claims that appeared
earlier in this post of yours--you'd be opening yourself up to
essentially the same formulaic response.

> Out of curiosity, would you consider it worthwhile for us to populate
> the galaxy with von Neumann machines?

Not if the smallest ones would be the size of Mount Everest. Do you
have any reason to think they could be made smaller?

>Arguably they're much better
> suited for the job

What job? The job of appreciating the wonder of the universe? Has
anyone (except maybe Douglas Hofstadter) imputed consciousness to von
Neumann machines?

> than any organic life, and we could probably add some
> evolutionary mechanisms to their makeup.

> >> They
> >> know that their sort of life worked, and achieved their goal of evolving
> >> into an intelligent species. Why mess with success?
>
> > Why would setting things in motion for another intelligent species
> > billions of years in the future be "messing with success"? You are
> > unusually hard to follow in this post, John.
>
> Why, if intelligence was their goal, would they abandon the only sort of
> life known to have produced intelligence (theirs) in favor of a
> completely untested alternative?

I gave a restrained response to this question in reply to Walter
Bushell.

[snip]

> >> And how can you equate stages in completely alien forms?
>
> > I'm working on that (and much else relevant to this sub-thread) now in
> > a sci.bio.evolution thread, "Expanding the Drake Equation."  You can
> > either wait until the thread seems spent, or join me there.
>
> I'll wait here.

Fine with me.

> >>> Of course, if someone [perhaps Mitchell, or Michael, or Mark] wants to
> >>> argue otherwise, I'm willing to listen.
> >> It makes a huge difference for you, since the probability of life
> >> supposedly increases as we go from 1 to 4,
>
> > Yes, but the probability of intelligent life is a huge unknown there,
> > as I've noted above.  It stands to reason that there is a trade-off,
> > the comparatively easier abiogenesis leading to a steeper climb to
> > achieve intelligence.  Golian life is obviously less diverse and
> > adaptable than Xordaxian, for example.
>
> I don't see that as being obvious.

Then you are missing out on a very basic point. Golian life is based
on far fewer amino acids than ours, maybe as few as four. Clearly, an
organism able to utilize a bigger range of amino acids has greater
potential for adaptability and for diversification.

> But even if there's a tradeoff,
> you're assuming that the tradeoffs cancel out.

Again you allege an assumption I did not make.

[remainder of GIGO snipped]

> >> and is apparently high for
> >> option 4. Now perhaps the probability of intelligence becomes lower as
> >> we go from 1 to 4, and all that balances out. But don't you have to
> >> think about it?
>
> > I've thought about it since before my December 2010 return, without
> > coming to any conclusions as to how the trade-off works, except for
> > what I've said just now.

But today I've been thinking: people have not batted an eye on the
hypothesized near-complete triumph of the protein takeover.
Presumably that is because proteins ARE better enzymes than
ribozymes. But if that is really true, than the Throomians would have
very good reasons for designing protein-based life. Of course, they
might have an emotional attachment to their kind, so they might send
out both kinds.

> Then your argument and your probability estimates are missing crucial
> features, wouldn't you agree?

Not crucial ones. The main probabilities that would be affected would
be the ones I never made: what are the relative probabilities of the
four sub-hypotheses wrt each other? I happen to think the Throomian
is the best shot, but that's just personal speculation without any
real thinking behind it.

Peter Nyikos

[John Harshman]

pnyikos wrote:
> On May 30, 3:43 pm, Walter Bushell <pr...@panix.com> wrote:
>> In article <4d-dnUoRc7jgplvS4p2d...@giganews.com>,
>> John Harshman <jharsh...@pacbell.net> wrote:
>>
>>
>>
>>> Why, if intelligence was their goal, would they abandon the only sort of
>>> life known to have produced intelligence (theirs) in favor of a
>>> completely untested alternative?
>
> I dunno why John said "abandon". Perhaps he hasn't gotten around to
> reading my second reply, on the other thread, where I wrote:
>
> [quote, beginning with John's words:]
>> They
>> know that their sort of life worked, and achieved their goal of evolving
>> into an intelligent species. Why mess with success?
>
> They could have sent several kinds, their own and the modified as
> well. Perhaps even the Xordaxians did that, only their kind of
> biochemistry triumphed in the early earth.
> [end of quote]

Not really an answer, but thanks for trying.

>> I like Larry Niven's fictional take, we are all descended from food
>> yeast that has gone bad.
>
> That's a slight improvement on the "space garbage" hypothesis of the
> 1960's as far as the "yuck [spelled "yecch" back then] factor" goes,
> but not much. Where does he have the food yeast originating?

On Thrintun, presumably. Read _World of Ptavvs_. Should tell you all you
need to know.

[Walter Bushell]

In article <H--dnWpiEMD...@giganews.com>,

They died out when the yeast mutated or starved to death. Their
skeletons were designed to be biodegradable.

But yes, the idea is fantastic, but what a lovely fantasy. If you need
intelligent design, probably the most likely true, but that is a low
bar to clear.

[James Beck]

On May 30, 11:23 am, John Harshman <jharsh...@pacbell.net> wrote:
> pnyikos wrote:
> I don't see that as being obvious. But even if there's a tradeoff,
> you're assuming that the tradeoffs cancel out. And if they cancel out,
> what reason can there be for your aliens to try radically different life?

Sure. There are always tradeoffs. Truly verdant woo demands an
occasional layer of doo. But really, why stop there? Why not
"hypothesize" a multiverse in overlapping space. That way, the
panspermists could spooge us in real time with any culture they want
to try out.

[jillery]

On Wed, 30 May 2012 13:58:08 -0700, Friar Broccoli <eli...@gmail.com>
wrote:

>
>Could you check your spam box for an email I sent you two days ago
>(Monday evening).

I didn't find anything :)

[Harry K]

For a change I agree with you. Comes right back to P making a whole
lot of unneeded assumptions to get to the conclusion he wants.

Harry K

[Steven L.]

"John Harshman" <jhar...@pacbell.net> wrote in message
news:4d-dnUoRc7j...@giganews.com:

>
> Why, if intelligence was their goal, would they abandon the only sort of
> life known to have produced intelligence (theirs) in favor of a
> completely untested alternative?

Perhaps their type of life could not survive in the conditions existing
on the primordial Earth.

Heck, without some kind of environmental suits and oxygen tanks, *we*
could not survive on the primordial Earth, if we could travel back in
time to that period.

That aliens would engineer life forms most likely to survive on the
planets of interest--even if those life forms were totally unlike their
own--isn't unreasonable.



-- Steven L.

[John Harshman]

Not part of Peter's scenario. But you are free to invent your own
scenarios. Yours has a variety of problematic consequences that we could
explore if you really cared.

[John Harshman]

Did I? I don't see any reply to that post from me. Are you sure?

>>> B. Diversifying the outcome. I did a long reply to Robert Camp, who
>>> seems to have quit this "Intelligent Design" thread, touching on
>>> this theme at length back in December 2010:
>>> http://groups.google.com/group/talk.origins/msg/44a5c533d7f0c9f6
>
> You might do well to click on that link and read it, in the light of
> your formulaic words below.

You might be a little more sparing with the casual insults. I see
"formulaic", "GIGO", "incompetent", "the way your mental apparatus
works", just in this post. They contributed nothing to your argument and
only serve to lower the level of discourse by inspiring me to reply
similarly. You moron. (Sorry, I got carried away.)

>>> C. Speeding up the outcome, by starting with a more adaptable
>>> organism. This is especially easier to see in comparing our
>>> biochemistry with the Golian.
>> This is really only a mechanism that allows you to postulate radically
>> different life forms for the seeders yet end up with our sort of life in
>> the seeded. These "justifications" are just special pleading.
>
> This formulaic response could be applied, with obvious changes in
> wording, to any attempt by anyone to give alternative explanations
> for anything.

Then again, on some occasions the application would be valid. There is
such a thing as special pleading, isn't there? So the question is
whether I'm right about this particular case, and you don't address that.

> If this is the way your mental apparatus works, it's no
> wonder you made no attempt to justify any of your claims that appeared
> earlier in this post of yours--you'd be opening yourself up to
> essentially the same formulaic response.

That didn't even make sense. Please stop reading my mind.

>> Out of curiosity, would you consider it worthwhile for us to populate
>> the galaxy with von Neumann machines?
>
> Not if the smallest ones would be the size of Mount Everest. Do you
> have any reason to think they could be made smaller?

I wasn't considering the size. But where did you get your size estimate,
and why should size matter?

>> Arguably they're much better
>> suited for the job
>
> What job? The job of appreciating the wonder of the universe? Has
> anyone (except maybe Douglas Hofstadter) imputed consciousness to von
> Neumann machines?

The job of spreading life, of a sort, through the galaxy. Has anyone
imputed consciousness to prokaryotes? Certainly you don't. So if the
goal is just life, what's wrong with von Neumann machines? And if the
goal is the rare evolution of intelligence, that's what my comment below
is about: make them evolvable, and they might achieve that state.

The point was to put you in the position of the Throomians. Our bizarre
sort of life would have been analogous to self-replicating machines from
their perspective. How much kinship do you feel with von Neumann
machines? Is spreading them through the universe just as good as
spreading prokaryotes? If so, fine. If not, consider the Throomians and
ask whether they would consider spreading prokaryotes as good as
spreading Throomlike organisms.

>> than any organic life, and we could probably add some
>> evolutionary mechanisms to their makeup.
>
>>>> They
>>>> know that their sort of life worked, and achieved their goal of evolving
>>>> into an intelligent species. Why mess with success?
>>> Why would setting things in motion for another intelligent species
>>> billions of years in the future be "messing with success"? You are
>>> unusually hard to follow in this post, John.
>> Why, if intelligence was their goal, would they abandon the only sort of
>> life known to have produced intelligence (theirs) in favor of a
>> completely untested alternative?
>
> I gave a restrained response to this question in reply to Walter
> Bushell.

I am very happy for you.

> [snip]
>
>>>> And how can you equate stages in completely alien forms?
>>> I'm working on that (and much else relevant to this sub-thread) now in
>>> a sci.bio.evolution thread, "Expanding the Drake Equation." You can
>>> either wait until the thread seems spent, or join me there.
>> I'll wait here.
>
> Fine with me.
>
>>>>> Of course, if someone [perhaps Mitchell, or Michael, or Mark] wants to
>>>>> argue otherwise, I'm willing to listen.
>>>> It makes a huge difference for you, since the probability of life
>>>> supposedly increases as we go from 1 to 4,
>>> Yes, but the probability of intelligent life is a huge unknown there,
>>> as I've noted above. It stands to reason that there is a trade-off,
>>> the comparatively easier abiogenesis leading to a steeper climb to
>>> achieve intelligence. Golian life is obviously less diverse and
>>> adaptable than Xordaxian, for example.
>> I don't see that as being obvious.
>
> Then you are missing out on a very basic point. Golian life is based
> on far fewer amino acids than ours, maybe as few as four. Clearly, an
> organism able to utilize a bigger range of amino acids has greater
> potential for adaptability and for diversification.

I don't see that as necessarily true. One should always be wary of
assumptions that are so obvious you don't need to defend them.

>> But even if there's a tradeoff,
>> you're assuming that the tradeoffs cancel out.
>
> Again you allege an assumption I did not make.

Technically true. In fact it's just an assumption you would have to make
in order to make ignoring the differences among scenarios reasonable.

> [remainder of GIGO snipped]
>
>>>> and is apparently high for
>>>> option 4. Now perhaps the probability of intelligence becomes lower as
>>>> we go from 1 to 4, and all that balances out. But don't you have to
>>>> think about it?
>>> I've thought about it since before my December 2010 return, without
>>> coming to any conclusions as to how the trade-off works, except for
>>> what I've said just now.
>
> But today I've been thinking: people have not batted an eye on the
> hypothesized near-complete triumph of the protein takeover.
> Presumably that is because proteins ARE better enzymes than
> ribozymes. But if that is really true, than the Throomians would have
> very good reasons for designing protein-based life. Of course, they
> might have an emotional attachment to their kind, so they might send
> out both kinds.

Even if your assumption about the relative merits of proteins and RNA is
correct, which it may well be, you have just advanced the required
technology of the Throomians by a giant leap. They must be able to
conceive of new chemistries quite unlike their own, survey them, and
come up with an alternative sort of life they have never seen, and
finally test it well enough to determine that it is indeed much better
than theirs for their purposes, i.e. resulting in intelligence. This
also suggests that 20 amino acids is some kind of optimum, since they
stopped at 20. Why wouldn't 30 be even better? Is ours the best of all
possible chemistries?

>> Then your argument and your probability estimates are missing crucial
>> features, wouldn't you agree?
>
> Not crucial ones.

If you had done any real thinking, you wouldn't have said that. Of
course you assume the existence of intelligent life and so omit it from
your calculations while simultaneously denying that you have a
conditional probability, so I see why you think the steps leading up to
that intelligence aren't crucial.

> The main probabilities that would be affected would
> be the ones I never made: what are the relative probabilities of the
> four sub-hypotheses wrt each other?

Nope. It also is required to assess any such hypothesis vs. terrestrial
abiogenesis.

> I happen to think the Throomian
> is the best shot, but that's just personal speculation without any
> real thinking behind it.

You need better names. Rather than nonsense words, try using names that
reflect the hypotheses. Since you have no thinking behind it, I won't
ask why you prefer one hypothesis over another.

[John Harshman]

No there isn't. That's the probability of seeding given the prior
existence of life. A conditional probability.

> You have not tried to
> dispute it. You have, instead, falsely claimed below that I am
> assuming that it happened already, in the past, in THIS galaxy. That
> is not an assumption, it is a cautious conclusion that the odds favor
> it.

Since you haven't calculated the odds that any such thing has happened,
I don't see how you can reach such a conclusion. You conclude that if
such a thing has happened we are more likely to be a result of it than
an independent origin. It's a conditional probability.

> Note that the above probability has to do with all galaxies, in all
> universes like ours in every essential respect.

I don't understand this claim. What does "has to do with" mean?

>>>> But by far the highest probability is
>>>> that there is none. You have computed the probability that, if someone
>>>> seeded the local area before us, we are not those people.
>
> The "before us" makes the probability 1. I never mentioned any such
> probability, let alone computed it.

You are wrong about this too. "Before us" just creates the possibility.
Even if parts of the galaxy were seeded, we might be in a different
part, or might be an unseeded planet in the same part, and could have
arisen on our own. And you never mentioned such a probability, so you
think, but that's what the probability you state boils down to.

>>> False.
>> Well, that settles things, then.
>
> Yes, and I think this time even you can see it. Do you still cling to
> the "backpedal" you did below?

You have apparently no capacity to notice irony. Do I have to start
adding smileys to my posts, or will you learn that "False." isn't a
convincing argument?

>>>> It seems to me
>>>> that you have shown that the probability is higher that nobody seeded
>>>> anything.
>>> I'd like to see your reasoning, if any, for this counterintuitive
>>> claim.
>
>> Why is it counterintuitive?
>
> Because I never said anything even remotely resembling it.

I had never previously realized that "counterintuitive" means "something
I didn't say". As Mark Twain said, use the word you want, not its second
cousin. You have shown it, but don't realize it.

If life arises on Throom, the probability that it will eventually seed
other planets is very small. Do you agree? The probability that it will
never seed other planets is quite close to 1. Do you agree? (Both using
your parameters.)

>> Again, you begin with the assumption that
>> there is a prior intelligent species on some other planet.
>
> Bizarre, this imputing of assumptions to me that I never made. And my
> clarification of the word "arises" below should have dispelled any
> thought in your mind that I made this one. Why do you cling to it?

Because it's an implication of your estimates. You don't consider the
probability of intelligence arising on Throom. Why not?

>>>>>>> So done. There: I've given you a stationary target to ask questions
>>>>>>> about and raise objections to.
>>>>>> That's certainly close to an argument. But it's incomplete. What are we
>>>>>> assuming about the initial life that "arises"?
>
> See, I talk about all three possibilities below.
>
>>>>> "arises" wasn't the best choice of words, I see: I should have said,
>>>>> "comes to be on a planet favorable for subsequent evolution". It
>>>>> could happen one of three natural [as opposed to supernatural ways]:
>>>>> homegrown abiogenesis, undirected panspermia, or placement by
>>>>> intelligent creatures that arose elsewhere.
>>>>> For the *initial* life form -- that one in a galaxy/universe
>>>>> happenstance according to my hypothesis, it would be via homegrown
>>>>> abiogenesis, although a lot of ingredients for it might have come from
>>>>> elsewhere.
>
> That's initial life, whether it goes on to produce creatures like
> ourselves, or not. Next I focus on the intelligent ones, and then
> narrow the focus further, after first making a general statement:
>
>>>>> I'm not making any assumptions as to the biological makeup of any
>>>>> intelligent creatures, including the hypothesized panspermists.
>
> They are the *conclusion* of my reasoning, and not my initial
> assumption.

But if the makeup of your creatures influences the probabilities (and it
should), you need to make such assumptions. Nor is their makeup a
conclusion of any reasoning; they're hypotheses that you agree you have
no evidence or argument to choose among.

How is this unclear? Where in your probability calculation do you
consider the probability of Throom existing? Why is that not relevant to
the question?

>>> We are given that we are here, and that we evolved from prokaryotes.
>>> As to whether those prokaryotes are due to minimal or no genetic
>>> modification -- something neither you nor Meyer would count as
>>> designing "a whole organism" -- as in the Xordaxian hypothesis, or
>>> something both of you would call that, as in the para-3M hypothesis,
>>> hardly seems relevant to the probabilities.
>
> [yet another repetition deleted here]
>
> So shoot me for not adding, "if they were seeded here" after the
> second "prokaryotes". Will you also accuse me of being a theist if I
> ever leave out "if there is a God" whenever I use the word "God"?

You seem to mistake the basis of my objection. It seems to me that if
we're trying to evaluate the relative probabilities of terrestrial
abiogenesis vs. panspermia, we need to consider both the probability of
terrestrial abiogenesis and the probability of Throomian abiogenesis and
evolution of intelligence. Why aren't these necessary?

[Mark Isaak]

On 5/30/12 5:14 PM, pnyikos wrote:
> On May 30, 3:52 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> wrote:
>> On 5/30/12 6:03 AM, pnyikos wrote:
>>
>>> On May 30, 8:30 am, prawnster<zweibro...@ymail.com> wrote:
>>> [...]
>>>> No, I don't subscribe to that mantra. My mantra is Goddidit, this I
>>>> know, because the Bible tells me so. And no one has provided any
>>>> evidence superior to that explanation.
>>
>>> Ah. I see you are of the Ray Martinez types, who does not extrapolate
>>> from C. S. Lewis's _Out of the Silent Planet_ and _Perelandra_ to the
>>> possibility that God might have inspired panspermists to spread life
>>> far and wide ca. 4 billion years ago, just as he inspired Noah to save
>>> a huge boatload of animals so they could be fruitful, multiply, and
>>> replenish the earth.
>>
>> You do Ray a grave disservice by comparing him to prawnster.
>
> Well, I haven't seen enough of prawnster yet to comment on that.
>
>> Prawnster's purpose on talk.origins is to make Ray and Dale look
>> entirely rational, Suzanne look intelligent, Mr. Dunsapy and Alan
>> Kleinman look open-minded, and Nando look kind-hearted by comparison.
>> By and large, he succeeds.
>
> How would you compare him to "vowel boy"?

Vowel boy is like a _Fannia_ house fly that annoys because it keeps
flying around and never goes away, but which never does anything worse
than that. Prawnster, in contrast, makes regular trips between dung
piles and your food, spreading disease.

> And, have you ever looked at Wretch Fossil's posts, over in
> sci.bio.paleontology?

I have never encountered him.

[John Harshman]

Interesting fellow, though in the "funny once" category. He first
emerged as Ed Conrad's one and only follower. But it later transpired
that he was only into Ed for the pareidolia, and he branched out. Now he
can find whole organisms (frogs, mammals) in Martian landscapes,
mammalian erythrocytes and neurons in any rock thin section, and blood
vessels in the sky in lunar photos. Oh, and the lunar landings were
faked; how and why not available, but there are neurons all over the
pictures in addition to the usual crap from moon landing conspiracy
theorists. Yes, and the original god has died and the new god is a
Chinese gentleman.

[Mark Isaak]

On 5/29/12 6:01 PM, pnyikos wrote:
> A theme that has occupied me on and off ever since I resumed posting
> to talk.origins in December 2010 is the probability of earth life
> having arisen from abiogenesis on earth as opposed to having been
> brought (or sent) here from another solar system by a spacefaring
> species that lived ca. 4 billion years ago.

The discussions of this topic have tended to go in many different
directions, engender animosity, and spawn all sorts of irrelevancies.
Notwithstanding all that, the idea is sufficiently intriguing that I
decided to consider it from scratch.

First, definition of the relevant variables:

pA = probability of Abiogenesis. More specifically, the probability,
given an earth-like planet, of life arising to a population and
robustness that, short of a cosmic catastrophe, it will not go
extinct for millions of years at least.
pP = probability of successful Pansperia. That is, the probability
that a single panspermia attempt on an earth-like planet will
result in life as described above.
pT = probability of Technological capability. Specifically, the
probability that, given life as described above, it will evolve
and develop a race technically capable of doing panspermia.
pS = probability, given the technical capability, that a race will
in fact attempt at least one panspermia seeding.
N = expected number of panspermia attempts by a race which is attempting
panspermia. By definition, N >= 1.
U = number of earth-like planets in the universe.

Thus, analogous to the Drake equation, we have

Number of planets alive by abiogenesis =
La = U * pA
Number of planets alive by pansperia =
Lp = U * pA * pT * pS * N * pP
Probability that a planet's life arose by panspermia = Lp / (Lp + La)

Note that Lp does not take into account second-generation panspermia --
panspermia from planets whose life originated by panspermia. There are
two reasons for this. First, it is questionable whether the universe is
old enough for life to evolve up to technical intelligence twice in
sequence. Second, given the uncertainties we already have, the issue is
moot. If panspermia is common, second-generation panspermia could add
to it, but if it is unlikely, a second generation would not make much of
a difference.

So what can we conclude? First, the probability that a planet's life
originated by panspermia is not affected by the probability of abiogenesis.

The factors that the probability *does* depend on are all unknown. Our
speculation on what might be reasonable values for pT, pS, N, and pP
need not be completely uninformed, but we really have very little to go on.

Herewith is my own speculation. The lone example of planetary life we
have to work with shows that technology can develop, so we have some
justification in setting pT fairly high. On the other hand, if
intelligence were very likely, it probably would have evolved a hundred
million years or more sooner than it did. My own wild guess is to put
pT at .6.

How likely is a race to attempt panspermia? Peter seems to take it as a
given, but it seems unlikely to me. Panspermia means taking away
resources for purposes that nobody on your planet will ever benefit
from. That sort of pure altruism is selected against by evolution, and
though evolutionarily disadvantageous behaviors can and do arise in
complex minds, we would not expect them to be widespread or long-term.
I think we could expect some halfhearted gestures similar to our
recordings on the Voyager probes, but not likely any dedicated programs
intended to have a reasonable chance at success. I put pS at .005.

The number of attempts at pansperia, and the likelihood of success per
attempt (N and pP) both depend on the cost of the attempts, in inverse
directions. Seeding plants can either produce lots of little seeds,
each with little chance of germinating, or a few robust seeds with much
greater survivability. Panspermia seeds would work the same. I will
assume that the Xordaxians (or Throomians, I forget who is who) would
not start the project unless they had reason to believe in some
successes, so I will call N * pP = 5 for any project, and maybe ten
projects over the life of the civilization, for N * pP = 50.

That puts my overall estimate of odds of pansperia at .13. But I
repeat, the estimates are little more than guesses and could easily be
off by orders of magnitude. Peter has a point that panspermia is within
the realm of plausibility. Without data, however, we cannot determine
more than that.

[John Harshman]

Note that in Peter's various scenarios there are multiple potential
types of life, each presumably with a different pA and pT. And probably
pP too. This complicates things. Though he's assuming that all
panspermia attempts will be using our type.

Further, he's more interested in the probability of us being here by
panspermia, so your numerator should have a pT factor too, and so
reduces to (pS * N * pP)/[(pS * N * pP)+1].

Given Peter's figures (and given that pT is also irrelevant), N * pP is
10^6 (he doesn't give these separately) and pS is 1/8, so the
probability that we're panspermized is nearly 1.

[pnyikos]

On Jun 1, 7:40 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>
wrote:

> On 5/29/12 6:01 PM, pnyikos wrote:
>
> > A theme that has occupied me on and off ever since I resumed posting
> > to talk.origins in December 2010 is the probability of earth life
> > having arisen from abiogenesis on earth as opposed to having been
> > brought (or sent) here from another solar system by a spacefaring
> > species that lived ca. 4 billion years ago.
>
> The discussions of this topic have tended to go in many different
> directions, engender animosity, and spawn all sorts of irrelevancies.
> Notwithstanding all that, the idea is sufficiently intriguing that I
> decided to consider it from scratch.

I'm glad you did, Mark.

> First, definition of the relevant variables:
>
> pA = probability of Abiogenesis.  More specifically, the probability,
>     given an earth-like planet, of life arising to a population and
>     robustness that, short of a cosmic catastrophe, it will not go
>     extinct for millions of years at least.

Prokaryotes like our own, including autotropes like cyanobacteria, on
a planet with prebiotic "soup" such as has been produced in
experiments like the Urey-Miller experiment, would fill the bill IMO.

> pP = probability of successful Pansperia.  That is, the probability
>     that a single panspermia attempt on an earth-like planet will
>     result in life as described above.

There is a lot to be said for what might be called a two-fold attempt,
so to speak, as follows. The first soft landings would include a
mixture of instruments (to report back about conditions) and various
varieties of organisms to picked areas deemed suitable on the basis of
prior instrumental flybys.

At the same time, an orbiting probe could send back information as to
what other areas show promise for a second probe, with much more of
the payload devoted to seeding.

> pT = probability of Technological capability.  Specifically, the
>     probability that, given life as described above, it will evolve
>     and develop a race technically capable of doing panspermia.

This is very much like the product of Drake's factors f_i and f_c, and
I gave an estimate of 0.00004 for f_i and 0.5 for f_c to begin with,
just to have something concrete to discuss. I see you guessed a much
higher number for something a little less likely than the product
below.

> pS = probability, given the technical capability, that a race will
>     in fact attempt at least one panspermia seeding.

I put that at between .5 and .25. See my first post to this thread.

> N = expected number of panspermia attempts by a race which is attempting
>     panspermia.  By definition, N >= 1.

I put something very similar at 250,000, with almost all of that due
to massive efforts of around a million.

> U = number of earth-like planets in the universe.
>
> Thus, analogous to the Drake equation, we have
>
> Number of planets alive by abiogenesis =
>    La = U * pA
> Number of planets alive by pansperia =
>    Lp = U * pA * pT * pS * N * pP
> Probability that a planet's life arose by panspermia = Lp / (Lp + La)

I have been emphasizing the probability that a planet with our level
of intelligent life -- capable of interstellar communication and
sending of instrumental probes -- had its life arise by panspermia.

> Note that Lp does not take into account second-generation panspermia --
> panspermia from planets whose life originated by panspermia.  There are
> two reasons for this.  First, it is questionable whether the universe is
> old enough for life to evolve up to technical intelligence twice in
> sequence.  Second, given the uncertainties we already have, the issue is
> moot.  If panspermia is common, second-generation panspermia could add
> to it,

...but probably not as much as the first. In one of my replies to
Harshman I said that before a really major panspermia project is
undertaken by a first-generation panspermia-derived species, I believe
it will likely have encountered at least one other planet with life of
some sort on it that was due to the original panspermists.

And that would put a bit of a damper on them undertaking a panspermia
project themselves: they would probably be far more wary of
contaminating existing life than the original panspermists would have
been.

You see, I put the factor of pA so low as to make abiogenesis a less-
than-once-in-a-galaxy event.

>but if it is unlikely, a second generation would not make much of
> a difference.
>
> So what can we conclude?  First, the probability that a planet's life
> originated by panspermia is not affected by the probability of abiogenesis.

Excellent. You show a better understanding of the basics in your first
try than Harshman has been able to attain to in about ten intensive
posts of his in reply to as many of mine.

.
> The factors that the probability *does* depend on are all unknown.  Our
> speculation on what might be reasonable values for pT, pS, N, and pP
> need not be completely uninformed, but we really have very little to go on.
>
> Herewith is my own speculation.  The lone example of planetary life we
> have to work with shows that technology can develop, so we have some
> justification in setting pT fairly high.

Why do you say this? If prokaryotes on pA level had never evolved us,
we wouldn't be here in the first place.

Concluded in next post.

Peter Nyikos

[pnyikos]

On Jun 1, 7:40 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>
wrote:

I've repeated a bit from my first reply to make this self-contained.

> First, definition of the relevant variables:
>
> pA = probability of Abiogenesis.  More specifically, the probability,
>     given an earth-like planet, of life arising to a population and
>     robustness that, short of a cosmic catastrophe, it will not go
>     extinct for millions of years at least.
> pP = probability of successful Pansperia.  That is, the probability
>     that a single panspermia attempt on an earth-like planet will
>     result in life as described above.
> pT = probability of Technological capability.  Specifically, the
>     probability that, given life as described above, it will evolve
>     and develop a race technically capable of doing panspermia.
> pS = probability, given the technical capability, that a race will
>     in fact attempt at least one panspermia seeding.
> N = expected number of panspermia attempts by a race which is attempting
>     panspermia.  By definition, N >= 1.
> U = number of earth-like planets in the universe.

I'm glad you said "universe" rather than "galaxy". Makes it much
easier to explain the probabilities, given my assumption that natural
abiogenesis is a less-than-once-in-a-galaxy event.

About pT, you wrote:

> On the other hand, if
> intelligence were very likely, it probably would have evolved a hundred
> million years or more sooner than it did.

The conditions have to be right for that. On our own earth, things
seemed to go very slowly until the Vendian/Ediacaran, when there was a
sudden explosion of multicellular forms, to be replaced not long after
by the products of the Cambrian explosion.

> My own wild guess is to put
> pT at .6.

One of the most optimistic I've seen. Carl Sagan puts f_i x f_c at .
01 in _Cosmos_.

On the "parent" thread, Harshman said biologists tend to set just f_i
much lower, but when I asked him for examples, he ducked the question.

> How likely is a race to attempt panspermia? Peter seems to take it as a
> given, but it seems unlikely to me.

No, I put it at ca. .0625, if by "a race" you mean an intelligent race
on the level of Cro-Magnon man, .125 if you mean a technological
civilization on our level. See my first post to the thread for
details -- the one to which you are replying.

> Panspermia means taking away
> resources for purposes that nobody on your planet will ever benefit
> from. That sort of pure altruism is selected against by evolution,

That depends on how broadly you interpret "That sort". Stephen Jay
Gould did a great essay in _The Panda's Thumb_ talking about how
hostile most evolutionary biologists were to the idea of any sort of
altruism being selected for, something that he didn't go along with.
Cleverly, he also provided the opposite extreme: Dawkins's silly
notion of "selfish genes" according to which individual organisms
aren't what are selected for, but rather subunits thereof.

> and
> though evolutionarily disadvantageous behaviors can and do arise in
> complex minds, we would not expect them to be widespread or long-term.

I take it you assume Christianity and Islam are soon to disappear.

> I think we could expect some halfhearted gestures similar to our
> recordings on the Voyager probes, but not likely any dedicated programs
> intended to have a reasonable chance at success. I put pS at .005.

I assume a technological species, on discovering life on pA level to
be confined to their planet after an enormous attempt at finding some
(including instrumental flybys and some instrumental soft landings)
elsewhere, would be fairly likely (.25 probability) to undertake an
enormous panspermia project, spread out over millions of years so as
not to put much of a burden on their solar-system-wide economy.

> The number of attempts at pansperia, and the likelihood of success per
> attempt (N and pP) both depend on the cost of the attempts, in inverse
> directions. Seeding plants can either produce lots of little seeds,
> each with little chance of germinating, or a few robust seeds with much
> greater survivability. Panspermia seeds would work the same. I will
> assume that the Xordaxians (or Throomians, I forget who is who) would
> not start the project unless they had reason to believe in some
> successes, so I will call N * pP = 5 for any project, and maybe ten
> projects over the life of the civilization, for N * pP = 50.

That's only if their objective is life on pA level. If their
objective is much closer to pT level, I would expect N to be huge,
since even the closest stars are so far away that they might never
attempt to visit any of their systems themselves, nor (for that
reason) to send organisms anywhere near their own level of
development.

> That puts my overall estimate of odds of pansperia at .13. But I
> repeat, the estimates are little more than guesses and could easily be
> off by orders of magnitude. Peter has a point that panspermia is within
> the realm of plausibility. Without data, however, we cannot determine
> more than that.

Thanks, Mark. As I continue to refine my ideas for what goes into the
various factors, I might end up with something like this too, and if
so I would continue to expound on the hypothesis of directed
panspermia just to keep the topic going.

Peter Nyikos

[Mark Isaak]

For purposes of the equation, that counts as a single seeding attempt
with a fairly high chance of success. It also reinforces my point that
a higher pP will cost more, and so will reduce the expected number of
attempts.

I thought about doing that, but the result of life is a necessary
milestone, and going to points beyond that seemed an unnecessary
complication.

And yet you yourself repeatedly emphasize the probability (or your
estimate of it) of abiogenesis. That does not make sense to me.

[Mark Isaak]

On 6/4/12 4:42 AM, pnyikos wrote:
> On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> wrote:
>
> I've repeated a bit from my first reply to make this self-contained.
>
>> First, definition of the relevant variables:
>>
>> pA = probability of Abiogenesis. More specifically, the probability,
>> given an earth-like planet, of life arising to a population and
>> robustness that, short of a cosmic catastrophe, it will not go
>> extinct for millions of years at least.
>> pP = probability of successful Pansperia. That is, the probability
>> that a single panspermia attempt on an earth-like planet will
>> result in life as described above.
>> pT = probability of Technological capability. Specifically, the
>> probability that, given life as described above, it will evolve
>> and develop a race technically capable of doing panspermia.
>> pS = probability, given the technical capability, that a race will
>> in fact attempt at least one panspermia seeding.
>> N = expected number of panspermia attempts by a race which is attempting
>> panspermia. By definition, N>= 1.
>> U = number of earth-like planets in the universe.
>
> I'm glad you said "universe" rather than "galaxy". Makes it much
> easier to explain the probabilities, given my assumption that natural
> abiogenesis is a less-than-once-in-a-galaxy event.

Actually, it makes no difference. One could consider the "universe" of
planets in the galaxy if one wishes. I repeat my conclusion that the
odds of abiogenesis do not enter into it.

> About pT, you wrote:
>
>> On the other hand, if
>> intelligence were very likely, it probably would have evolved a hundred
>> million years or more sooner than it did.
>
> The conditions have to be right for that. On our own earth, things
> seemed to go very slowly until the Vendian/Ediacaran, when there was a
> sudden explosion of multicellular forms, to be replaced not long after
> by the products of the Cambrian explosion.
>
>> My own wild guess is to put pT at .6.
>
> One of the most optimistic I've seen. Carl Sagan puts f_i x f_c at .
> 01 in _Cosmos_.

Like I said, wild guesses all around. I simply have trouble justifying
a very low probability for an event that has occurred, without
exception, in every trial we have seen. Although, since that is a
single trial, I guess I should lower it to .5.

>> How likely is a race to attempt panspermia? Peter seems to take it as a
>> given, but it seems unlikely to me.
>
> No, I put it at ca. .0625, if by "a race" you mean an intelligent race
> on the level of Cro-Magnon man, .125 if you mean a technological
> civilization on our level. See my first post to the thread for
> details -- the one to which you are replying.

I stand corrected.

>> Panspermia means taking away
>> resources for purposes that nobody on your planet will ever benefit
>> from. That sort of pure altruism is selected against by evolution,
>
> That depends on how broadly you interpret "That sort". Stephen Jay
> Gould did a great essay in _The Panda's Thumb_ talking about how
> hostile most evolutionary biologists were to the idea of any sort of
> altruism being selected for, something that he didn't go along with.
> Cleverly, he also provided the opposite extreme: Dawkins's silly
> notion of "selfish genes" according to which individual organisms
> aren't what are selected for, but rather subunits thereof.

"Pure altruism" has a fairly standard and specific definition --
behavior that benefits another and imposes a cost and no benefit on its
performer. It is something that, when it has a genetic component, will
not survive evolution.

Most of what we call altruism either has direct if not always obvious
benefits (for example, contributing to a street beggar raises your
status in the eyes of onlookers) or is a complex result of other
behaviors which have such benefits (for example, sacrificing oneself in
war is a case of mutual helping in a very close-knit social group, with
a dose of reflex actions for an emergency).

The panspermia you propose is pure altruism. It is theoretically
impossible to maintain over multiple generations.

>> and
>> though evolutionarily disadvantageous behaviors can and do arise in
>> complex minds, we would not expect them to be widespread or long-term.
>
> I take it you assume Christianity and Islam are soon to disappear.

Hardly. Those are nowhere near pure altruism. Nowhere near.

>> I think we could expect some halfhearted gestures similar to our
>> recordings on the Voyager probes, but not likely any dedicated programs
>> intended to have a reasonable chance at success. I put pS at .005.
>
> I assume a technological species, on discovering life on pA level to
> be confined to their planet after an enormous attempt at finding some
> (including instrumental flybys and some instrumental soft landings)
> elsewhere, would be fairly likely (.25 probability) to undertake an
> enormous panspermia project, spread out over millions of years so as
> not to put much of a burden on their solar-system-wide economy.

As I have noted in the past, there is no basis for that assumption that
I can see.

>> The number of attempts at pansperia, and the likelihood of success per
>> attempt (N and pP) both depend on the cost of the attempts, in inverse
>> directions. Seeding plants can either produce lots of little seeds,
>> each with little chance of germinating, or a few robust seeds with much
>> greater survivability. Panspermia seeds would work the same. I will
>> assume that the Xordaxians (or Throomians, I forget who is who) would
>> not start the project unless they had reason to believe in some
>> successes, so I will call N * pP = 5 for any project, and maybe ten
>> projects over the life of the civilization, for N * pP = 50.
>
> That's only if their objective is life on pA level. If their
> objective is much closer to pT level, I would expect N to be huge,
> since even the closest stars are so far away that they might never
> attempt to visit any of their systems themselves, nor (for that
> reason) to send organisms anywhere near their own level of
> development.

One thing I left out of my analysis is colonization. If the originating
civilization's goal was life at the pT level, their objective would be
more easily met by colonization rather than panspermy (except insofar as
panspermy was a forerunner to terraform the worlds for colonization).

I am more and more convinced that a productive analysis will need to
consider N * pP together. The panspermists, if smart enough to make
space probes, will presumably be able to estimate the odds of success of
individual probes, and calculate the number of probes for the overall
success of the project.

What, then, is the goal of the project? To answer that, we need to
understand the psychology of a species totally alien to us, in the most
literal sense. That is an impossible task. I have assumed only that
the goal is to spread life, since that is the premise once you get to
these terms in the equation. You assume that the goal is to make life
extremely widespread. I do not think you can support that assumption.

[pnyikos]

On Jun 4, 12:20 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>

wrote:
> On 6/4/12 4:26 AM, pnyikos wrote:
> > On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> > wrote:

> >> pA = probability of Abiogenesis.  More specifically, the probability,
> >>      given an earth-like planet, of life arising to a population and
> >>      robustness that, short of a cosmic catastrophe, it will not go
> >>      extinct for millions of years at least.
>
> > Prokaryotes like our own, including autotropes like cyanobacteria, on
> > a planet with prebiotic "soup" such as has been produced in
> > experiments like the Urey-Miller experiment, would fill the bill IMO.

Would you agree with this, Mark?

> >> pP = probability of successful Pansperia.  That is, the probability
> >>      that a single panspermia attempt on an earth-like planet will
> >>      result in life as described above.
>
> > There is a lot to be said for what might be called a two-fold attempt,
> > so to speak, as follows. The first soft landings would include a
> > mixture of instruments (to report back about conditions) and various
> > varieties of organisms to picked areas deemed suitable on the basis of
> > prior instrumental flybys.
>
> > At the same time, an orbiting probe could send back information as to
> > what other areas show promise for a second probe, with much more of
> > the payload devoted to seeding.
>
> For purposes of the equation, that counts as a single seeding attempt
> with a fairly high chance of success.  It also reinforces my point that
> a higher pP will cost more, and so will reduce the expected number of
> attempts.

Or cause them to be spread over a greater period of time.

You emphasize the cost of such efforts, but if we ever colonize a
number of asteroids and moons, we'll have access to a tremendous array
and amount of resources, including conventional fuel from the methane
lakes of Titan. So I don't think shortage of materials would be a
problem for us or from any other would-be panspermists on our level of
progress. [I won't say technology, the progress needed there is within
our reach already.]

[...]

> >> pS = probability, given the technical capability, that a race will
> >>      in fact attempt at least one panspermia seeding.
>
> > I put that at between .5 and .25.  See my first post to this thread.
>
> >> N = expected number of panspermia attempts by a race which is attempting
> >>      panspermia.  By definition, N>= 1.
>
> > I put something very similar at 250,000, with almost all of that due
> > to massive efforts of around a million.
>
> >> U = number of earth-like planets in the universe.
>
> >> Thus, analogous to the Drake equation, we have
>
> >> Number of planets alive by abiogenesis =
> >>     La = U * pA
> >> Number of planets alive by pansperia =
> >>     Lp = U * pA * pT * pS * N * pP
> >> Probability that a planet's life arose by panspermia = Lp / (Lp + La)
>
> > I have been emphasizing the probability that a planet with our level
> > of intelligent life -- capable of interstellar communication and
> > sending of instrumental probes -- had its life arise by panspermia.
>
> I thought about doing that, but the result of life is a necessary
> milestone, and going to points beyond that seemed an unnecessary
> complication.

It's a good first step, but one of the main questions about which I am
concerned is whether *we* are the product, via evolution, of directed
panspermia, or of abiogenesis. A lot of readers here dismiss the
former possibility out of hand, and even those who do not, like
Harshman, apparently believe its probability is very low.

[...]

> >> So what can we conclude?  First, the probability that a planet's life
> >> originated by panspermia is not affected by the probability of abiogenesis.
>
> > Excellent. You show a better understanding of the basics in your first
> > try than Harshman has been able to attain to in about ten intensive
> > posts of his in reply to as many of mine.
>
> And yet you yourself repeatedly emphasize the probability (or your
> estimate of it) of abiogenesis.  That does not make sense to me.

Well, it's a theme that you will already find in the original directed
panspermia article by Crick and Orgel. A species that sees that it is
apparently alone in the galaxy, would decide that it is up to them to
realize the great potential for life, if it is to happen at all. They
may well decide that the rich possibilities for life on suitable
planets are worth the trouble of ensuring that life on a grand scale
will exist in the future.

Icarus 19 (1973) 341-346:
http://profiles.nlm.nih.gov/ps/access/SCBCCP.pdf

[pnyikos]

Since there is life, that is understood.

Almost any probability can be thought of as a conditional one. The
probability of a card randomly chosen from a standard deck being an
ace is a conditional probability, conditional on the existence of
standard decks of cards, and their makeup.

> > You have not tried to
> > dispute it.  You have, instead, falsely claimed below that I am
> > assuming that it happened already, in the past, in THIS galaxy.  That
> > is not an assumption, it is a cautious conclusion that the odds favor
> > it.
>
> Since you haven't calculated the odds that any such thing has happened,

There you go again, counting your chickens before they are hatched.
You are assuming that a line of reasoning, only part of which you are
divulging here, is correct, and are giving me the conclusion of that
line.

Evidently all my talk about counter-counter-counter...arguments on the
parent thread went like water off a duck's back.

> I don't see how you can reach such a conclusion. You conclude that if
> such a thing has happened we are more likely to be a result of it than
> an independent origin. It's a conditional probability.
>
> > Note that the above probability has to do with all galaxies, in all
> > universes like ours in every essential respect.
>
> I don't understand this claim. What does "has to do with" mean?

You seem to be trying to apply the Socratic Method here and in many
other places, both on this thread and the "parent" thread, but
Socrates was much more constructive in his questions than you are.

Let's try an analogy: suppose there were only one coin in the whole
universe, and there was only one chance to flip it before it was
destroyed. How meaningful would it be to say that it is equally
likely to come up heads or tails on that one flip?

We humans are much more comfortable with comments like these: given a
huge number of flips, a fair coin is likely to come up heads very
close to half the time.

> >>>> But by far the highest probability is
> >>>> that there is none. You have computed the probability that, if someone
> >>>> seeded the local area before us, we are not those people.
>
> > The "before us" makes the probability 1.  I never mentioned any such
> > probability, let alone computed it.
>
> You are wrong about this too. "Before us" just creates the possibility.

Try as I might, I cannot interpret the part after "the probability
that," in any way other than as an analogue of:

If Leif Ericson discovered America before Columbus,
then Leif Ericson wasn't Columbus.

> Even if parts of the galaxy were seeded, we might be in a different
> part, or might be an unseeded planet in the same part, and could
> have arisen on our own.

Well, duh. I thought such things were understood from what I wrote
above.

> And you never mentioned such a probability, so you
> think, but that's what the probability you state boils down to.

I fail to see how this paraphrases what you wrote above. And so I am
sticking by my original analysis:

> >>> False.
> >> Well, that settles things, then.
>
> > Yes, and I think this time even you can see it.  Do you still cling to
> > the "backpedal" you did below?
>
> You have apparently no capacity to notice irony.

Did the import of the words "and maybe this time even you can see it"
completely escape the higher centers of your brain, or are you just
playing dumb in order to score the following cheap shot?

> Do I have to start
> adding smileys to my posts, or will you learn that "False." isn't a
> convincing argument?

Hint: If I hadn't noticed the irony, I would either not have said
anything or have said something like "I'm glad you agree."

Oh, wait. Maybe what you were really looking for was a piece of
counter-irony, and "I'm glad you agree" would have been interpreted by
you as such.

And now, I'm going to beat you to the punch and ask,

Can we dispense with the personal comments and get back to talking
about on-topic stuff?

Remainder deleted, to be replied to later.

Peter Nyikos

[pnyikos]

On Jun 4, 1:07 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>

And I concur with it in the sense of what one does with the above
probabilities once they have been estimated. However, as I tried to
explain in my reply around an hour ago, my estimate of N depends
rather strongly on pA being very low.

> > About pT, you wrote:
>
> >> On the other hand, if
> >> intelligence were very likely, it probably would have evolved a hundred
> >> million years or more sooner than it did.
>
> > The conditions have to be right for that.  On our own earth, things
> > seemed to go very slowly until the Vendian/Ediacaran, when there was a
> > sudden explosion of multicellular forms, to be replaced not long after
> > by the products of the Cambrian explosion.
>
> >> My own wild guess is to put pT at .6.
>
> > One of the most optimistic I've seen.  Carl Sagan puts f_i x f_c at .
> > 01 in _Cosmos_.
>
> Like I said, wild guesses all around.  I simply have trouble justifying
> a very low probability for an event that has occurred, without
> exception, in every trial we have seen.

You are being very "empirical", and making no effort to apply
reasoning. But as I am sure you are aware, it is very risky to
conclude much of anything from a sample of one, in most ordinary
statistical analyses.

> Although, since that is a
> single trial, I guess I should lower it to .5.

There are lots of satires about how estimating a probability of .5
under such circumstances can give to ridiculous conclusions. Haven't
you read any of them?

> >> How likely is a race to attempt panspermia?  Peter seems to take it as a
> >> given, but it seems unlikely to me.
>
> > No, I put it at ca. .0625, if by "a race" you mean an intelligent race
> > on the level of Cro-Magnon man, .125 if you mean a technological
> > civilization on our level.  See my first post to the thread for
> > details -- the one to which you are replying.
>
> I stand corrected.
>
> >>   Panspermia means taking away
> >> resources for purposes that nobody on your planet will ever benefit
> >> from.  That sort of pure altruism is selected against by evolution,
>
> > That depends on how broadly you interpret "That sort".  Stephen Jay
> > Gould did a great essay in _The Panda's Thumb_ talking about how
> > hostile most evolutionary biologists were to the idea of any sort of
> > altruism being selected for, something that he didn't go along with.
> > Cleverly, he also provided the opposite extreme: Dawkins's silly
> > notion of "selfish genes" according to which individual organisms
> > aren't what are selected for, but rather subunits thereof.
>
> "Pure altruism" has a fairly standard and specific definition --
> behavior that benefits another and imposes a cost and no benefit on its
> performer.  It is something that, when it has a genetic component, will
> not survive evolution.

Do you think the grand old Jewish custom of giving alms without
expecting anything in return -- and, if possible, without the
beneficiary -- or anyone else -- even seeing the almsgiver or having
any idea who [s]he is -- is destined to not survive the evolution of
human society?

I take it from your name that you come from a Jewish background. Are
you still close enough to it to appreciate this grand old custom?

And now, I must leave the rest for later. Duty calls.

Peter Nyikos

[John Harshman]

But life on earth isn't the prior existence you're assuming. Since,
however, you have now embraced Mark Isaak's formula, which is a ratio in
which the probability of life cancels out, this becomes a moot question.

And the remainder of this post becomes irrelevant too.

[pnyikos]

OK, I think I've finally figured out what one allegation of Harshman's
is really saying. I am leaving in something earlier that sheds some
light on the way I handle it this time around.

[...]

> > > You have not tried to
> > > dispute it.  You have, instead, falsely claimed below that I am
> > > assuming that it happened already, in the past, in THIS galaxy.  That
> > > is not an assumption, it is a cautious conclusion that the odds favor
> > > it.

[...]

> > > Note that the above probability has to do with all galaxies, in all
> > > universes like ours in every essential respect.

[...]

> Let's try an analogy: suppose there were only one coin in the whole
> universe, and there was only one chance to flip it before it was
> destroyed.  How meaningful would it be to say that it is equally
> likely to come up heads or tails on that one flip?
>
> We humans are much more comfortable with comments like these: given a
> huge number of flips, a fair coin is likely to come up heads very
> close to half the time.

And I think most knowledgeable readers here would like for there to be
a lot of different planets on which life arose, whether by directed
panspermia or by abiogenesis. And so the bigger the sample, the
better.

> > >>>> But by far the highest probability is
> > >>>> that there is none. You have computed the probability that, if someone
> > >>>> seeded the local area before us, we are not those people.

I think now that this means: "You have computed the probability that,
even if someone seeded something somewhere in the local area [whatever
that means], we did not arise from whatever 'seed' they sent, but from
homegrown abiogenesis."

This is incorrect, but at least it bears a remote resemblance to what
I did.

[...]

> Try as I might, I cannot interpret the part after "the probability
> that," in any way other than as an analogue of:
>
>   If Leif Ericson discovered America before Columbus,
>   then Leif Ericson wasn't Columbus.

This interpreted "people" as including all intelligent species.

> > Even if parts of the galaxy were seeded,

"parts of the universe" would be better.

> > we might be in a different
> > part, or might be an unseeded planet in the same part, and could
> > have arisen on our own.

Even if one interprets "the local area" as "the local group of
galaxies," what John said originally was incorrect. I do not assume
seeding took place anywhere in our universe. All I am assuming is
that there is a sufficiently stupendous number of universes
essentially like ours so that seeding has taken place many, many
times, and I am averaging the outcome over all those times and all the
times life arose via abiogenesis on a planet.

"sufficiently stupendous number of universes" is, IMHO, the only way
atheism can be far more likely than theism.

Peter Nyikos

[pnyikos]

I am assuming only the existence of lots of life spread out over a
stupendous number of universes. See my own reply to my own post to
which you are replying here.

And since there is no reason to think that there is any meaning to the
claim "our present time means the following moment in this other
universe", the word "prior" is out of place.

> Since,
> however, you have now embraced Mark Isaak's formula, which is a ratio in
> which the probability of life cancels out, this becomes a moot question.

It always did cancel out, but you wasted a huge amount of time, both
in this thread and the other, by thinking it didn't cancel out, and
concluding that your faulty reasoning HAD to be correct, and only
giving me the conclusions of that reasoning.

Had you taken to heart what I wrote about counter-counter-
counter...arguments, you would not have been so cocksure as to only
give me the end results of your "reasonings."

> And the remainder of this post becomes irrelevant too.

As does most of what you wrote in the "parent" thread after you pulled
this same sort of big deletion and told me, "Try it."

Oh, well, at least I don't have to answer most of what you wrote
there. In particular, you've saved me the trouble of posting that
100+ line essay that I promised after you wrote, "Do you realize what
you are doing?" and gave me another faulty conclusion.

Peter Nyikos

[Mark Isaak]

On 6/4/12 12:02 PM, pnyikos wrote:
> On Jun 4, 12:20 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> wrote:
>> On 6/4/12 4:26 AM, pnyikos wrote:
>>> On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
>>> wrote:
>
>>>> pA = probability of Abiogenesis. More specifically, the probability,
>>>> given an earth-like planet, of life arising to a population and
>>>> robustness that, short of a cosmic catastrophe, it will not go
>>>> extinct for millions of years at least.
>>
>>> Prokaryotes like our own, including autotropes like cyanobacteria, on
>>> a planet with prebiotic "soup" such as has been produced in
>>> experiments like the Urey-Miller experiment, would fill the bill IMO.
>
> Would you agree with this, Mark?

Of course. I thought it went without saying.

>>>> pP = probability of successful Pansperia. That is, the probability
>>>> that a single panspermia attempt on an earth-like planet will
>>>> result in life as described above.
>>
>>> There is a lot to be said for what might be called a two-fold attempt,
>>> so to speak, as follows. The first soft landings would include a
>>> mixture of instruments (to report back about conditions) and various
>>> varieties of organisms to picked areas deemed suitable on the basis of
>>> prior instrumental flybys.
>>
>>> At the same time, an orbiting probe could send back information as to
>>> what other areas show promise for a second probe, with much more of
>>> the payload devoted to seeding.
>>
>> For purposes of the equation, that counts as a single seeding attempt
>> with a fairly high chance of success. It also reinforces my point that
>> a higher pP will cost more, and so will reduce the expected number of
>> attempts.
>
> Or cause them to be spread over a greater period of time.
>
> You emphasize the cost of such efforts, but if we ever colonize a
> number of asteroids and moons, we'll have access to a tremendous array
> and amount of resources, including conventional fuel from the methane
> lakes of Titan. So I don't think shortage of materials would be a
> problem for us or from any other would-be panspermists on our level of
> progress. [I won't say technology, the progress needed there is within
> our reach already.]

I am not convinced that methane from Titan counts as cheap energy,
considering that you would need to get molecular oxygen from somewhere, too.

A sufficiently advanced civilization could get costs down to the point
where a modest program would not bankrupt civilization, but for the
large number of probes you are talking about, they would have to be
nearly disposable.

> [...]

>>> I have been emphasizing the probability that a planet with our level
>>> of intelligent life -- capable of interstellar communication and
>>> sending of instrumental probes -- had its life arise by panspermia.
>>
>> I thought about doing that, but the result of life is a necessary
>> milestone, and going to points beyond that seemed an unnecessary
>> complication.
>
> It's a good first step, but one of the main questions about which I am
> concerned is whether *we* are the product, via evolution, of directed
> panspermia, or of abiogenesis. A lot of readers here dismiss the
> former possibility out of hand, and even those who do not, like
> Harshman, apparently believe its probability is very low.

I think we are all agreed that the probability that humans arose by
panspermia is somewhere between extremely low and extremely high, and
that narrowing down more than that requires a heck of a lot more data.
Alternatively, one could make risky predictions about what one would
expect from panspermia but not abiogenesis (e.g. alien satellites still
in orbit). That route requires a different lines of thinking, plus
wariness that one is not fooling oneself about what counts as evidence.

> [...]
>
>>>> So what can we conclude? First, the probability that a planet's life
>>>> originated by panspermia is not affected by the probability of abiogenesis.
>>
>>> Excellent. You show a better understanding of the basics in your first
>>> try than Harshman has been able to attain to in about ten intensive
>>> posts of his in reply to as many of mine.
>>
>> And yet you yourself repeatedly emphasize the probability (or your
>> estimate of it) of abiogenesis. That does not make sense to me.
>
> Well, it's a theme that you will already find in the original directed
> panspermia article by Crick and Orgel. A species that sees that it is
> apparently alone in the galaxy, would decide that it is up to them to
> realize the great potential for life, if it is to happen at all. They
> may well decide that the rich possibilities for life on suitable
> planets are worth the trouble of ensuring that life on a grand scale
> will exist in the future.
>
> Icarus 19 (1973) 341-346:
> http://profiles.nlm.nih.gov/ps/access/SCBCCP.pdf

I have not read the Icarus paper, but what you describe sounds like an
unwarranted attempt to read the minds of aliens. I would say it is just
as likely that the aliens will see what a mess life can make of things
and systematically work to ensure that it does *not* start up anywhere else.

[Mark Isaak]

Your estimate of N depends on at least two assumptions: a very low pA
and an expectation of alien motives. Since the latter is completely
unknown, an estimate of pA adds nothing.

>>> About pT, you wrote:
>>
>>>> On the other hand, if
>>>> intelligence were very likely, it probably would have evolved a hundred
>>>> million years or more sooner than it did.
>>
>>> The conditions have to be right for that. On our own earth, things
>>> seemed to go very slowly until the Vendian/Ediacaran, when there was a
>>> sudden explosion of multicellular forms, to be replaced not long after
>>> by the products of the Cambrian explosion.
>>
>>>> My own wild guess is to put pT at .6.
>>
>>> One of the most optimistic I've seen. Carl Sagan puts f_i x f_c at .
>>> 01 in _Cosmos_.
>>
>> Like I said, wild guesses all around. I simply have trouble justifying
>> a very low probability for an event that has occurred, without
>> exception, in every trial we have seen.
>
> You are being very "empirical", and making no effort to apply
> reasoning.

Rejecting empiricism would not be very reasonable, don't you agree?

> But as I am sure you are aware, it is very risky to
> conclude much of anything from a sample of one, in most ordinary
> statistical analyses.

Keep in mind, though, that tool use has arisen independently in multiple
lineages, including at least two phyla. The base of data is slightly
bigger than just humans.

>> [...]

>>>> Panspermia means taking away
>>>> resources for purposes that nobody on your planet will ever benefit
>>>> from. That sort of pure altruism is selected against by evolution,
>>
>>> That depends on how broadly you interpret "That sort". Stephen Jay
>>> Gould did a great essay in _The Panda's Thumb_ talking about how
>>> hostile most evolutionary biologists were to the idea of any sort of
>>> altruism being selected for, something that he didn't go along with.
>>> Cleverly, he also provided the opposite extreme: Dawkins's silly
>>> notion of "selfish genes" according to which individual organisms
>>> aren't what are selected for, but rather subunits thereof.
>>
>> "Pure altruism" has a fairly standard and specific definition --
>> behavior that benefits another and imposes a cost and no benefit on its
>> performer. It is something that, when it has a genetic component, will
>> not survive evolution.
>
> Do you think the grand old Jewish custom of giving alms without
> expecting anything in return -- and, if possible, without the
> beneficiary -- or anyone else -- even seeing the almsgiver or having
> any idea who [s]he is -- is destined to not survive the evolution of
> human society?
>
> I take it from your name that you come from a Jewish background. Are
> you still close enough to it to appreciate this grand old custom?

There are other factors to keep in mind. First, what people actually do
is very different from what their ideals are. The religious leaders can
extol virtues constantly, but that does not mean the people will always
follow. In fact, the whole reason for the "constantly" is because
people regularly do not follow.

Second, when someone wants to be a very good piano player, they spend a
lot of time playing even when nobody else is listening. If someone
wants to be a very good person, it makes sense that they should do it
even when nobody else is looking. And even from a purely pragmatic and
materialist standpoint, the rewards for being a good person are
considerable.

Incidentally, I am not from a Jewish background, though I have a slight
familiarity with that background through friends and through my readings
of folklore and religion.

[Roger Shrubber]

Mark Isaak wrote:
> On 6/4/12 4:26 AM, pnyikos wrote:
>> On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>

>>> pP = probability of successful Pansperia. That is, the probability
>>> that a single panspermia attempt on an earth-like planet will
>>> result in life as described above.
>>
>> There is a lot to be said for what might be called a two-fold attempt,
>> so to speak, as follows. The first soft landings would include a
>> mixture of instruments (to report back about conditions) and various
>> varieties of organisms to picked areas deemed suitable on the basis of
>> prior instrumental flybys.
>>
>> At the same time, an orbiting probe could send back information as to
>> what other areas show promise for a second probe, with much more of
>> the payload devoted to seeding.
>
> For purposes of the equation, that counts as a single seeding attempt
> with a fairly high chance of success. It also reinforces my point that a
> higher pP will cost more, and so will reduce the expected number of
> attempts.

Actually, a two phase effort would, IMO, drastically reduce pP.
The time span between initiation of the effort to launch probes
and recovery of the results would be large. Based on our experience,
it would span many generations. Where have we seen stable motives
over say 20 generations? The time required to get feedback reduces
the chance of even trying. The likelihood of caring after the delay
is not high in my estimation, suggesting no follow-up. And the scatter
in time of feedback means the caring would have to be long term in
order to generate a sustained effort.

At to this, what are the moral implications of seeding?
Is something akin to "the prime directive" going to inhibit impulses
to 'pollute' the universe with life? Probably.

[pnyikos]

I've already shown how misguided this last sentence was, in my first
reply. On the "parent" thread you are acting as though you had never
seen it. I'll be referring to it in reply to that post of yours.

Today, I am tackling this post from a different angle.

> Since,
> however, you have now embraced Mark Isaak's formula, which is a ratio in
> which the probability of life cancels out, this becomes a moot question.

Not quite. You have to replace "probability of life" with
"probability of technological civilization" to get to where anything
becomes moot.

But I'll save you the trouble, by tweaking Mark's analysis a bit.

Here is what he wrote:

pA = probability of Abiogenesis. More specifically, the probability,
given an earth-like planet, of life arising to a population and
robustness that, short of a cosmic catastrophe, it will not go
extinct for millions of years at least.

pP = probability of successful Pansperia. That is, the probability
that a single panspermia attempt on an earth-like planet will
result in life as described above.

pT = probability of Technological capability. Specifically, the
probability that, given life as described above, it will evolve
and develop a race technically capable of doing panspermia.
pS = probability, given the technical capability, that a race will
in fact attempt at least one panspermia seeding.
N = expected number of panspermia attempts by a race which is
attempting
panspermia. By definition, N >= 1.
U = number of earth-like planets in the universe.

Thus, analogous to the Drake equation, we have

Number of planets alive by abiogenesis =
La = U * pA
Number of planets alive by pansperia =
Lp = U * pA * pT * pS * N * pP
Probability that a planet's life arose by panspermia = Lp / (Lp + La)

============ end of Mark's algebraic analysis

Now let's introduce two more numbers:

Number of planets with technological species that arose via
abiogenesis on their planet:
Ta = U * pA * pT
Number of planets with technological species that arose via seeding of
their planet by panspermists:
Tp = U * pA * pT * pS * N * pP
Probability that a planet's technological life arose by panspermia =
Tp / (Tp + Ta)

And this time, U * pA * pT cancels out, showing that your figure of .
0000025 for the above probability was not based on anything I wrote,
inasmuch as my average figure for N was 125,000 and my figure for pP
was around .5 Here is what you wrote on the "parent" thread:

"given your numbers, if life arises once in a
galaxy, or universe, or whatever, the probability that any other
planets
ever get life is around 0.0000025. It seems, then, much more likely
that
we are that one planet rather than some other place."

> And the remainder of this post becomes irrelevant too.

This too is wrong: on the parent thread, you insisted on reviving what
you deleted here: you asked me whether I agreed that my "False" was
useless. Apparently your claim of "irrelevant" is just an excuse for
you leaving the kitchen on this thread because you couldn't stand the
heat.

Peter Nyikos

[pnyikos]

On Jun 6, 5:45 am, Roger Shrubber <rog.shrubb...@gmail.com> wrote:
> Mark Isaak wrote:
> > On 6/4/12 4:26 AM, pnyikos wrote:
> >> On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> >>> pP = probability of successful Pansperia. That is, the probability
> >>> that a single panspermia attempt on an earth-like planet will
> >>> result in life as described above.
>
> >> There is a lot to be said for what might be called a two-fold attempt,
> >> so to speak, as follows. The first soft landings would include a
> >> mixture of instruments (to report back about conditions) and various
> >> varieties of organisms to picked areas deemed suitable on the basis of
> >> prior instrumental flybys.
>
> >> At the same time, an orbiting probe could send back information as to
> >> what other areas show promise for a second probe, with much more of
> >> the payload devoted to seeding.
>
> > For purposes of the equation, that counts as a single seeding attempt
> > with a fairly high chance of success. It also reinforces my point that a
> > higher pP will cost more, and so will reduce the expected number of
> > attempts.
>
> Actually, a two phase effort would, IMO, drastically reduce pP.
> The time span between initiation of the effort to launch probes
> and recovery of the results would be large.

That's if a technological species makes only a token attempt at
panspermia. But I envision at least one-eighth of them making a long-
term project out of it, in which case this is simply a matter of
seeding one planet rather than two with a tiny fraction of the total
effort.

I think about half of the species on our level, given enough time,
will send probes on flybys to many solar systems with planets as
favorably situated for life as our own. My abiogenesis hypothesis
says that, in the absence of prior seeding, they are almost sure to
find no life at all, not even prokaryote level, only lots of
"prebiotic soup" or not even that. [It just now occurred to me that
probiotic soup might not linger for billions of years, even if the
planet continues to be as well situated as earth is; geological events
and asteroid crashes might combine to degrade it.]

But I don't expect them to be easily discouraged; after all, the
discovery that they are alone in the galaxy is "mighty sobering" as
Pogo's friend Porky said at the end of an oft-quoted comment, and they
would want to explore (in the sense of sending "unmanned' probes for a
close look) an enormous number of systems before coming to such a
revolutionary conclusion.

Part of that exploration would consist of sending landers and orbiters
to the most likely planets. At some point, they would substitute
micro-organisms and machines used to protect and deliver them for some
of the instruments, and this time the original kinds of instruments,
and the orbiters, would have a slightly different purpose of detecting
where a second seeding would be most likely to take hold and prosper.

> Based on our experience,
> it would span many generations. Where have we seen stable motives
> over say 20 generations?

You picked that to go to the beginning of modern science, didn't you?
As we survey the scene, it seems to me that modern science is a lot
more likely to continue indefinitely than is did up to the beginning
of the 20th century.

Also, the Age of Exploration began right about the same time, and the
initial form [exploration of the land] is showing signs of coming to
an end only because there is little left to explore there. But the
exploration of the depths of the oceans still has a good way to go,
and shows no sign of abating.

And, as time goes by, the really big unexplored frontier for science
will probably become exobiology, and if we find no life forms in our
own solar system, there is a good chance we will "explore" many
promising planets with instruments.

> The time required to get feedback reduces
> the chance of even trying.

Within 12 light years of earth are Tau Ceti, Epsilon Eridani, and
Epsilon Indi, all of which are stable suns, a little less luminous
than ours (IIRC the epsilons are K-stars rather than G-stars like Sol)
but their systems are still good candidates for life. We could get
feedback in 120 years from instrumental flybys that we have the
capability of initiating in a decade or two if we were to make them a
high priority.

Even Alpha Centauri, despite the two main stars being so close
together, is a possibility. We could get feedback from there within
40 years.

We waited at least one-third as long for Voyager II to send back
signals from Neptune and its satellites.

> The likelihood of caring after the delay
> is not high in my estimation, suggesting no follow-up. And the scatter
> in time of feedback means the caring would have to be long term in
> order to generate a sustained effort.

Exobiology is a huge magnet. Just think of how excited
cryptobiologists would be if any of their pet targets (like Susquatch
or Mokele-mbebe) turned out to exist.

> At to this, what are the moral implications of seeding?
> Is something akin to "the prime directive" going to inhibit impulses
> to 'pollute' the universe with life? Probably.

The prime directive in Star Trek had to do with *existing*
civilizations. The analogy is to planets with life on them already,
and that is not part of my hypothesis.

Peter Nyikos

[John Harshman]

No, you merely claimed how misguided it was. We can forget all this if
you adopt Mark Isaak's math.

> On the "parent" thread you are acting as though you had never
> seen it. I'll be referring to it in reply to that post of yours.

Really, this is no longer interesting. If you're less interested in how
I've wronged you than in attacking the question of probabilities, you'll
just adopt Isaak's formula and move on.

> Today, I am tackling this post from a different angle.
>
>
>> Since,
>> however, you have now embraced Mark Isaak's formula, which is a ratio in
>> which the probability of life cancels out, this becomes a moot question.
>
> Not quite. You have to replace "probability of life" with
> "probability of technological civilization" to get to where anything
> becomes moot.

Which is easy enough to do, since he already has a factor for that. You
just have to put it in the one place where it isn't already present.

Yes, yes, I've already done that.

P(life originated on earth)= 1/(1 + [pS*N*pP]).

> And this time, U * pA * pT cancels out, showing that your figure of .
> 0000025 for the above probability was not based on anything I wrote,
> inasmuch as my average figure for N was 125,000 and my figure for pP
> was around .5 Here is what you wrote on the "parent" thread:

I never presented a figure for the above probability, since you never
presented a formula for it. But the figure using your numbers is 1/(1 +
..125 * 125,000 * .5) or 1/7813, i.e. nearly certain that life didn't
originate here. I'm pretty sure you never came up with that figure either.

So now we can think about your numbers.

> "given your numbers, if life arises once in a
> galaxy, or universe, or whatever, the probability that any other
> planets
> ever get life is around 0.0000025. It seems, then, much more likely
> that
> we are that one planet rather than some other place."

>> And the remainder of this post becomes irrelevant too.
>
> This too is wrong: on the parent thread, you insisted on reviving what
> you deleted here: you asked me whether I agreed that my "False" was
> useless. Apparently your claim of "irrelevant" is just an excuse for
> you leaving the kitchen on this thread because you couldn't stand the
> heat.

Is it absolutely essential that you triumphantly demonstrate your
victory over poor, silly me? OK, you are the winner.

[Mike Painter]

>
> Actually, it makes no difference. One could consider the "universe" of
> planets in the galaxy if one wishes. I repeat my conclusion that the
> odds of abiogenesis do not enter into it.

If abiogenesis does not enter into it then you are postulating a god
creating life that may then try to spread life by some means through out
the universe.

Allowing for abiogenesis and given the estimated age of the earth as
4.54 ą 0.05 billion years they would have to have reached a similar
point at least that long ago (plus travel time which could add another
billion years or so).
Is there any reason to believe that they took less time to develop?


Even if they took longer to develop, it happened there, why not here?

[pnyikos]

On Jun 5, 12:03 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>

wrote:
> On 6/4/12 12:58 PM, pnyikos wrote:

> > On Jun 4, 1:07 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> > wrote:
> >> On 6/4/12 4:42 AM, pnyikos wrote:
>
> >>> On Jun 1, 7:40 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> >>> wrote:
>
> >>> I've repeated a bit from my first reply to make this self-contained.
>
> >>>> First, definition of the relevant variables:
>
> >>>> pA = probability of Abiogenesis.  More specifically, the probability,
> >>>>       given an earth-like planet, of life arising to a population and
> >>>>       robustness that, short of a cosmic catastrophe, it will not go
> >>>>       extinct for millions of years at least.
> >>>> pP = probability of successful Pansperia.  That is, the probability
> >>>>       that a single panspermia attempt on an earth-like planet will
> >>>>       result in life as described above.
> >>>> pT = probability of Technological capability.  Specifically, the
> >>>>       probability that, given life as described above, it will evolve
> >>>>       and develop a race technically capable of doing panspermia.
> >>>> pS = probability, given the technical capability, that a race will
> >>>>       in fact attempt at least one panspermia seeding.
> >>>> N = expected number of panspermia attempts by a race which is attempting
> >>>>       panspermia.  By definition, N>= 1.
> >>>> U = number of earth-like planets in the universe.

Picking up where the last post left off, we come to some discussion
relevant to the numbers pA and N.

> >> [...]
> >>>> Panspermia means taking away
> >>>> resources for purposes that nobody on your planet will ever benefit
> >>>> from. That sort of pure altruism is selected against by evolution,
>
> >>> That depends on how broadly you interpret "That sort". Stephen Jay
> >>> Gould did a great essay in _The Panda's Thumb_ talking about how
> >>> hostile most evolutionary biologists were to the idea of any sort of
> >>> altruism being selected for, something that he didn't go along with.
> >>> Cleverly, he also provided the opposite extreme: Dawkins's silly
> >>> notion of "selfish genes" according to which individual organisms
> >>> aren't what are selected for, but rather subunits thereof.
>
> >> "Pure altruism" has a fairly standard and specific definition --
> >> behavior that benefits another and imposes a cost and no benefit on its
> >> performer. It is something that, when it has a genetic component, will
> >> not survive evolution.
>
> > Do you think the grand old Jewish custom of giving alms without
> > expecting anything in return -- and, if possible, without the
> > beneficiary -- or anyone else -- even seeing the almsgiver or having
> > any idea who [s]he is -- is destined to not survive the evolution of
> > human society?

After I posted this, I recalled the right word for that custom:
mitzvah. See below.

> > I take it from your name that you come from a Jewish background. Are
> > you still close enough to it to appreciate this grand old custom?
>
> There are other factors to keep in mind. First, what people actually do
> is very different from what their ideals are. The religious leaders can
> extol virtues constantly, but that does not mean the people will always
> follow. In fact, the whole reason for the "constantly" is because
> people regularly do not follow.

But there are enough people, I think, who are altruistic to make my
scenarios feasible. Part of the reason I think only about one-eighth
of all technological civilizations go on to become panspermists is
that the majority might lack sufficiently altruistic and long-sighted
leaders.

>
> Second, when someone wants to be a very good piano player, they spend a
> lot of time playing even when nobody else is listening. If someone
> wants to be a very good person, it makes sense that they should do it
> even when nobody else is looking.

You are getting a bit far from your original application of one theory
of biological evolution about pure altruism, don't you think?

> And even from a purely pragmatic and
> materialist standpoint, the rewards for being a good person are
> considerable.

The book of Job suggests otherwise. Sure, Job was rewarded in the
end, but in the heart of the book he goes on and on about how the
wicked prosper and the good are at a disadvantage. See Chapters 21
and especially 24. See also Jeremiah 12: 1-4.

> Incidentally, I am not from a Jewish background, though I have a slight
> familiarity with that background through friends and through my readings
> of folklore and religion.

Here is what one site says about mitzvah:

" In order to successfully fulfill a Mitzvah you have to perform an
act of kindness that is above and beyond the normal act of kindness.
It is performing an act that is completely selfless. One such act of
kindness that is often referenced when referring to a Mitzvah is
burying someone unknown. This is completely selfless and considered to
be a Mitzvah. While other acts can also be a Mitzvah, they need to
follow the same lines. They need to be acts that help someone else,
but do not actually help the person who performed them.

" A Mitzvah is really what religion should be built upon. Random acts
of kindness will always have a place in religion, and they help
society every time they are performed. Mitzvahs are necessary in order
for religion to remain powerful in the world today. They get to the
heart of religion and remind people what faith is really about.

" Goodness has a place in every religion. Performing a mitzvah is one
of the most important things anyone can do in a religion. When people
perform acts of kindness, they remember why they believe in their
religion. They believe because of the goodness, and that goodness
allows them to help others."
[end of quote]

Peter Nyikos

[pnyikos]

On Jun 5, 12:03 pm, Mark Isaak <eci...@curioustaxonomyNOSPAM.net>

As I said, Crick and Orgel gave one possibility (involving altruism,
which I discuss below) specifically based on the assumption that pA is
exceedingly low, and I think it can be a powerful motive in at least
one-fourth of the cases where a species would have the information
that pA *is* exceedingly low.

Also, I believe a species at our stage of technology has about an even
chance of getting a good estimate of pA. See my reply to Roger
Shrubber less than an hour ago.

> >>> About pT, you wrote:
>
> >>>> On the other hand, if
> >>>> intelligence were very likely, it probably would have evolved a hundred
> >>>> million years or more sooner than it did.
>
> >>> The conditions have to be right for that.  On our own earth, things
> >>> seemed to go very slowly until the Vendian/Ediacaran, when there was a
> >>> sudden explosion of multicellular forms, to be replaced not long after
> >>> by the products of the Cambrian explosion.
>
> >>>> My own wild guess is to put pT at .6.
>
> >>> One of the most optimistic I've seen.  Carl Sagan puts f_i x f_c at .
> >>> 01 in _Cosmos_.
>
> >> Like I said, wild guesses all around.  I simply have trouble justifying
> >> a very low probability for an event that has occurred, without
> >> exception, in every trial we have seen.
>
> > You are being very "empirical", and making no effort to apply
> > reasoning.
>
> Rejecting empiricism would not be very reasonable, don't you agree?

Yes, the two complement each other.

> > But as I am sure you are aware, it is very risky to
> > conclude much of anything from a sample of one, in most ordinary
> > statistical analyses.
>
> Keep in mind, though, that tool use has arisen independently in multiple
> lineages, including at least two phyla.  The base of data is slightly
> bigger than just humans.

But that is already far along towards intelligence. The big
bottleneck seems to be the stages from prokaryotes to metazoans, as
Harshman has pointed out. But even there, the fossil record could
conceivably hold some surprises for us. Moreover, we need to
understand just *why* metazoans are such late arrivals, and that could
influence our reasoning as to how hard that step is on the average
planet.

By the way, on a lower gravity planet (think Titan moved to the
location of earth) there could be quite an "evolutionary race" between
terrestrial creatures with exoskeletons and those with endoskeletons
(like us vertebrates) towards intelligence capable of sophisticated
technology, not just tool use.

[Mark Isaak]

On 6/6/12 12:33 PM, pnyikos wrote:
> On Jun 5, 12:03 pm, Mark Isaak<eci...@curioustaxonomyNOSPAM.net>
> wrote:

>> [snip. Back up if you missed anything.]

>>
>> Your estimate of N depends on at least two assumptions: a very low pA
>> and an expectation of alien motives. Since the latter is completely
>> unknown, an estimate of pA adds nothing.
>
> As I said, Crick and Orgel gave one possibility (involving altruism,
> which I discuss below) specifically based on the assumption that pA is
> exceedingly low,

And as I said a sentence earlier, the other unknown factors that go into
their possibility render any value of pA moot. It is still moot two
sentences later.

> and I think it can be a powerful motive in at least
> one-fourth of the cases where a species would have the information
> that pA *is* exceedingly low.

That's another thing. The civilization would have almost exactly zero
chance of ever knowing that pA is exceedingly low. If pA is high, that
could be established by finding life here and there. But to show pA is
so low that life is unlikely to have arisen again in the universe, you
would have to visit every place in the universe to rule out that life
has arisen there.

> Also, I believe a species at our stage of technology has about an even
> chance of getting a good estimate of pA.

You are dreaming.

> See my reply to Roger Shrubber less than an hour ago.

I saw nothing there relevant to estimating pA.

>> [re probability of developing technology]

>> Keep in mind, though, that tool use has arisen independently in multiple
>> lineages, including at least two phyla. The base of data is slightly
>> bigger than just humans.
>
> But that is already far along towards intelligence. The big
> bottleneck seems to be the stages from prokaryotes to metazoans, as
> Harshman has pointed out. But even there, the fossil record could
> conceivably hold some surprises for us. Moreover, we need to
> understand just *why* metazoans are such late arrivals, and that could
> influence our reasoning as to how hard that step is on the average
> planet.

I disagree, but that is an issue for another time. We already agree
that any estimates are uncertain to the degree of several orders of
magnitude.

> Concluded in next post.

And brought back here.

>>>> [...]
>>>>>> Panspermia means taking away
>>>>>> resources for purposes that nobody on your planet will ever benefit
>>>>>> from. That sort of pure altruism is selected against by evolution,
>>
>>>>> That depends on how broadly you interpret "That sort". Stephen Jay
>>>>> Gould did a great essay in _The Panda's Thumb_ talking about how
>>>>> hostile most evolutionary biologists were to the idea of any sort of
>>>>> altruism being selected for, something that he didn't go along with.
>>>>> Cleverly, he also provided the opposite extreme: Dawkins's silly
>>>>> notion of "selfish genes" according to which individual organisms
>>>>> aren't what are selected for, but rather subunits thereof.
>>
>>>> "Pure altruism" has a fairly standard and specific definition --
>>>> behavior that benefits another and imposes a cost and no benefit
>>>> on its performer. It is something that, when it has a genetic
>>>> component, will not survive evolution.
>>
>>> Do you think the grand old Jewish custom of giving alms without
>>> expecting anything in return -- and, if possible, without the
>>> beneficiary -- or anyone else -- even seeing the almsgiver or having
>>> any idea who [s]he is -- is destined to not survive the evolution of
>>> human society?
>

> After I posted this, I recalled the right word for that custom:
> mitzvah. See below.

I was already familiar with it.

>> There are other factors to keep in mind. First, what people
>> actually do is very different from what their ideals are. The
>> religious leaders can extol virtues constantly, but that does
>> not mean the people will always follow.
>> In fact, the whole reason for the "constantly" is because
>> people regularly do not follow.
>

> But there are enough people, I think, who are altruistic to make my
> scenarios feasible. Part of the reason I think only about one-eighth
> of all technological civilizations go on to become panspermists is
> that the majority might lack sufficiently altruistic and long-sighted
> leaders.

Note that "I think." How many of those people do you know well enough
to judge how altruistic they will be? For all you know, their altruism
may take the form of keeping the natural beauty of the universe free
from the corrupting influence of life. More plausibly, their altruism
means taking care of their neighbors rather than shooting resources into
space where they will never see them again.

In fact, your proposal might sound more plausible if drop the word
"altruism" from its description. I personally have trouble thinking of
the early Spanish explorers of the New World as "altruistic" as they
destroyed entire cultures to remake the continents on their own terms.
What you are suggesting sounds like similar motives.

The bottom line, though, is that the reason you are suggesting why
aliens do panspermy are not based on anything we know about aliens; the
reason comes entirely, 100%, from your own imagination. Now, that is
not such a bad starting point when your imagination is all you have to
work with, but do keep in mind that it is your idea that you are talking
about, and not the aliens'.

[Roger Shrubber]

That isn't clear, meaning I don't know what you are claiming.
The one eight part is clear enough although both arbitrary and specific.
But I don't understand the one rather than two allusion.

> I think about half of the species on our level, given enough time,
> will send probes on flybys to many solar systems with planets as
> favorably situated for life as our own. My abiogenesis hypothesis
> says that, in the absence of prior seeding, they are almost sure to
> find no life at all, not even prokaryote level, only lots of
> "prebiotic soup" or not even that. [It just now occurred to me that
> probiotic soup might not linger for billions of years, even if the
> planet continues to be as well situated as earth is; geological events
> and asteroid crashes might combine to degrade it.]

This last bit is odd and just piles arbitrary assertion upon arbitrary
assertion. It also suggests you know next to nothing about the chemistry
and thermodynamics that ostensibly drives accumulation of 'prebiotic soup'.

> But I don't expect them to be easily discouraged; after all, the
> discovery that they are alone in the galaxy is "mighty sobering" as
> Pogo's friend Porky said at the end of an oft-quoted comment, and they
> would want to explore (in the sense of sending "unmanned' probes for a
> close look) an enormous number of systems before coming to such a
> revolutionary conclusion.

The motivation you ascribe to these progenitors is rather fanciful.
My bias is that it derives from some idealism rather than observation
of what exists here.

> Part of that exploration would consist of sending landers and orbiters
> to the most likely planets. At some point, they would substitute
> micro-organisms and machines used to protect and deliver them for some
> of the instruments, and this time the original kinds of instruments,
> and the orbiters, would have a slightly different purpose of detecting
> where a second seeding would be most likely to take hold and prosper.
>
>> Based on our experience,
>> it would span many generations. Where have we seen stable motives
>> over say 20 generations?

> You picked that to go to the beginning of modern science, didn't you?

Not intentionally. My thinking was based on the Iroquois notion
of the seventh generation and I just extended it 3 fold
and then rounded. I just figured if we are that pathetically bad
at planning just 7 generations out, tripling that would dilute
things into total obscurity. For what it's worth, my take on the
7th generation is that, in the extreme, a great grandfather
might be able to directly tell a story to their great grandson,
that could be someday related to a great grandson, bridging over
7 generations. Beyond that, linkage and motivation is too
impersonal to have a hope. I fancy that to be an observation.

> As we survey the scene, it seems to me that modern science is a lot
> more likely to continue indefinitely than is did up to the beginning
> of the 20th century.

Any presumption that we are a privileged case is suspect.

> Also, the Age of Exploration began right about the same time, and the
> initial form [exploration of the land] is showing signs of coming to
> an end only because there is little left to explore there. But the
> exploration of the depths of the oceans still has a good way to go,
> and shows no sign of abating.
>
> And, as time goes by, the really big unexplored frontier for science
> will probably become exobiology, and if we find no life forms in our
> own solar system, there is a good chance we will "explore" many
> promising planets with instruments.

Charmingly naive.

>> The time required to get feedback reduces
>> the chance of even trying.
>
> Within 12 light years of earth are Tau Ceti, Epsilon Eridani, and
> Epsilon Indi, all of which are stable suns, a little less luminous
> than ours (IIRC the epsilons are K-stars rather than G-stars like Sol)
> but their systems are still good candidates for life. We could get
> feedback in 120 years from instrumental flybys that we have the
> capability of initiating in a decade or two if we were to make them a
> high priority.
>
> Even Alpha Centauri, despite the two main stars being so close
> together, is a possibility. We could get feedback from there within
> 40 years.
>
> We waited at least one-third as long for Voyager II to send back
> signals from Neptune and its satellites.
>
>
>> The likelihood of caring after the delay
>> is not high in my estimation, suggesting no follow-up. And the scatter
>> in time of feedback means the caring would have to be long term in
>> order to generate a sustained effort.
>
> Exobiology is a huge magnet. Just think of how excited
> cryptobiologists would be if any of their pet targets (like Susquatch
> or Mokele-mbebe) turned out to exist.

What fraction of today's humanity gives a damn about ancient human
fossils? Significantly less than your 1/8th. In a battle to compete
for resources, who is going to fund these fanciful exploration
programs? The motivations for space exploration so far have been
competing with rivals. You imagine this altruistic conversion that
is not compatible with my observation of Earthly life.

>> At to this, what are the moral implications of seeding?
>> Is something akin to "the prime directive" going to inhibit impulses
>> to 'pollute' the universe with life? Probably.

> The prime directive in Star Trek had to do with *existing*
> civilizations. The analogy is to planets with life on them already,
> and that is not part of my hypothesis.

Slippery slope.

[pnyikos]

On Jun 7, 8:17 am, Roger Shrubber <rog.shrubb...@gmail.com> wrote:
> pnyikos wrote:
> > On Jun 6, 5:45 am, Roger Shrubber<rog.shrubb...@gmail.com>  wrote:

[picking up where I left off in my first reply]

> > As we survey the scene, it seems to me that modern science is a lot

> > more likely to continue indefinitely than [it] did up to the beginning

> > of the 20th century.
>
> Any presumption that we are a privileged case is suspect.

So what future do you envision for science?

> > Also, the Age of Exploration began right about the same time, and the
> > initial form [exploration of the land] is showing signs of coming to
> > an end only because there is little left to explore there. But the
> > exploration of the depths of the oceans still has a good way to go,
> > and shows no sign of abating.
>
> > And, as time goes by, the really big unexplored frontier for science
> > will probably become exobiology, and if we find no life forms in our
> > own solar system, there is a good chance we will "explore" many
> > promising planets with instruments.
>
> Charmingly naive.

So what's your prognosis? That we will never send probes even as far
as Alpha Centauri? As you objected and I replied earlier...

> >> The time required to get feedback reduces
> >> the chance of even trying.
>
> > Within 12 light years of earth are Tau Ceti, Epsilon Eridani, and
> > Epsilon Indi, all of which are stable suns, a little less luminous
> > than ours (IIRC the epsilons are K-stars rather than G-stars like Sol)
> > but their systems are still good candidates for life. We could get
> > feedback in 120 years from instrumental flybys that we have the
> > capability of initiating in a decade or two if we were to make them a
> > high priority.
>
> > Even Alpha Centauri, despite the two main stars being so close
> > together, is a possibility. We could get feedback from there within
> > 40 years.
>
> > We waited at least one-third as long for Voyager II to send back
> > signals from Neptune and its satellites.

Didn't you have any thoughts on these matters?

> >> The likelihood of caring after the delay
> >> is not high in my estimation, suggesting no follow-up. And the scatter
> >> in time of feedback means the caring would have to be long term in
> >> order to generate a sustained effort.
>
> > Exobiology is a huge magnet. Just think of how excited
> > cryptobiologists would be if any of their pet targets (like Susquatch
> > or Mokele-mbebe) turned out to exist.
>
> What fraction of today's humanity gives a damn about ancient human
> fossils?

Enough to keep research alive. But nobody expects any big surprises
here any more.

> Significantly less than your 1/8th. In a battle to compete
> for resources,

"resources" is a highly misused word. I take it you are talking about
financial resources, but what's relevant is the number of man-hours
devoted to the project, because I don't think lack of REAL resources
is going to be a problem if we ever get around to mining asteroids.

> who is going to fund these fanciful exploration
> programs?

In the not too god-awful future, I think there is an even chance that
there will be people stationed on lots of asteroids and some moons,
mining them for minerals and sending them back to earth, being well
supplied to keep them happy, and building spacecraft capable of the
great journeys to other solar systems.

>The motivations for space exploration so far have been
> competing with rivals.

Not Voyager I and II. The Soviets had pretty much thrown in the towel
by then.

> You imagine this altruistic conversion that
> is not compatible with my observation of Earthly life.

A few hundred years ago, a lot of things we take for granted today
were not compatible with the observations of the people living then.
One is the lack of slavery in the Western world. Another is the
shortage of wars being fought for trivial reasons between the leading
countries of the world.

I am more optimistic than you, that's more and more abundantly clear.

> >> At to this, what are the moral implications of seeding?
> >> Is something akin to "the prime directive" going to inhibit impulses
> >> to 'pollute' the universe with life? Probably.
>
> > The prime directive in Star Trek had to do with *existing*
> > civilizations. The analogy is to planets with life on them already,
> > and that is not part of my hypothesis.
>
> Slippery slope.

Pessimism.

Peter Nyikos

[pnyikos]

[unsupported denial by you snipped]

> > On the "parent" thread you are acting as though you had never
> > seen it.  I'll be referring to it in reply to that post of yours.

[sudden lack of interest by you snipped]

> > Today, I am tackling this post from a different angle.
>
> >> Since,
> >> however, you have now embraced Mark Isaak's formula, which is a ratio in
> >> which the probability of life cancels out, this becomes a moot question.
>
> > Not quite.  You have to replace "probability of life" with
> > "probability of technological civilization" to get to where anything
> > becomes moot.
>
> Which is easy enough to do, since he already has a factor for that. You
> just have to put it in the one place where it isn't already present.

As it turns out, I became careless at one point, and so I would have
gotten something ridiculously close to 1 for the probability of us
arising by panspermia, by leaving out a crucial factor that has to be
added at the end of Mark's longer equation.

> > But I'll save you the trouble, by tweaking Mark's analysis a bit.
> > Here is what he wrote:
>
> > pA = probability of Abiogenesis.  More specifically, the probability,
> >     given an earth-like planet, of life arising to a population and
> >     robustness that, short of a cosmic catastrophe, it will not go
> >     extinct for millions of years at least.
> > pP = probability of successful Pansperia.  That is, the probability
> >     that a single panspermia attempt on an earth-like planet will
> >     result in life as described above.

I gave .5 here, but that was because I initially considered two probes
to be separate attempts. Howevewr, all along i've been talking about
number of planets seeded, not number of probes sent, and so "attempt"
really covers up to two seedings, and my estimate now is .8.

> > pT = probability of Technological capability.  Specifically, the
> >     probability that, given life as described above, it will evolve
> >     and develop a race technically capable of doing panspermia.

I gave .00002 here.

> > pS = probability, given the technical capability, that a race will
> >     in fact attempt at least one panspermia seeding.
> > N = expected number of panspermia attempts by a race which is
> > attempting
> >     panspermia.

My estimate for pS * N was 125, 000

>  By definition, N >= 1.
> > U = number of earth-like planets in the universe.
>
> > Thus, analogous to the Drake equation, we have
>
> > Number of planets alive by abiogenesis =
> >    La = U * pA
> > Number of planets alive by pansperia =
> >    Lp = U * pA * pT * pS * N * pP
> > Probability that a planet's life arose by panspermia = Lp / (Lp + La)

> > ============ end of Mark's algebraic analysis
>
> > Now let's introduce two more numbers:
> > Number of planets with technological species that arose via
> > abiogenesis on their planet:
> > Ta = U * pA * pT
> > Number of planets with technological species that arose via seeding of
> > their planet by panspermists:
> > Tp = U * pA * pT * pS * N * pP

I forgot to add the factor pT to the end of this second figure. The
above is simply Mark's number for number of planets that have stable,
prosperous life on them. And so:

Tp = U * pA * pT * pS * N * pP * pT

> > Probability that a planet's technological life arose by panspermia =
> > Tp / (Tp + Ta)

With U * pA * pT canceling out of both numerator and denominator, the
numerator becomes pS * N * pP * pT
= 100,000 * .00002 = 2.

And the denominator thus becomes 2+1 = 3, giving a probability of 2/3.

> Yes, yes, I've already done that.

You messed up by sticking to life.

> P(life originated on earth)= 1/(1 + [pS*N*pP]).

> > And this time, U * pA * pT cancels out, showing that your figure of .
> > 0000025 for the above probability was not based on anything I wrote,
> > inasmuch as my average figure for N was 125,000 and my figure for pP
> > was around .5 Here is what you wrote on the "parent" thread:
>
> I never presented a figure for the above probability, since you never
> presented a formula for it. But the figure using your numbers is 1/(1 +
> ..125 * 125,000 * .5) or 1/7813,

> i.e. nearly certain that life didn't
> originate here.

You are using the wrong conditional probability. Ours isn't just any
old planet with life; ours is a planet with a technological species on
it.

I do expect that for every planet like ours, there are thousands where
the initial seeding went fine, but then for one reason or another, it
will never progress to a technological species like ourselves.

> I'm pretty sure you never came up with that figure either.
>

On this, we are in complete agreement (!)

You never did divulge the basis for this other claim of yours:

> > "given your numbers, if life arises once in a
> > galaxy, or universe, or whatever, the probability that any other
> > planets
> > ever get life is around 0.0000025. It seems, then, much more likely
> > that
> > we are that one planet rather than some other place."

But now I think we can agree to forget this earlier attempt of yours.

> >> And the remainder of this post becomes irrelevant too.
>
> > This too is wrong: on the parent thread, you insisted on reviving what
> > you deleted here: you asked me whether I agreed that my "False" was
> > useless.  Apparently your claim of "irrelevant" is just an excuse for
> > you leaving the kitchen on this thread because you couldn't stand the
> > heat.
>
> Is it absolutely essential that you triumphantly demonstrate your
> victory over poor, silly me?

This is an even more blatant "underdog" act than the earlier one on
the "parent thread," belied in the same way as the original one but
also by the way you invested some triumph of your own into your
revival of the "False" issue.

You've been breathing down my neck for over a year and a half now,
upbraiding me for so many things that I've lost count, with me
sometimes fighting back and sometimes letting you have your way, like
when some talk.abortion regulars invaded talk.origins and you kept
after me not to reply to them, not even accidentally.

> OK, you are the winner.

Thanks. :-)

Peter Nyikos

[pnyikos]

Isn't it obvious? Both concepts are covered with me saying "There is
a lot to be said for what might be called a two-fold attempt,' and
Mark saying, "that counts as a single seeding attempt with a fairly
high chance of success."

> > I think about half of the species on our level, given enough time,
> > will send probes on flybys to many solar systems with planets as
> > favorably situated for life as our own.  My abiogenesis hypothesis
> > says that, in the absence of prior seeding, they are almost sure to
> > find no life at all, not even prokaryote level, only lots of
> > "prebiotic soup" or not even that. [It just now occurred to me that
> > probiotic soup might not  linger for billions of years, even if the
> > planet continues to be as well situated as earth is; geological events
> > and asteroid crashes might combine to degrade it.]
>
> This last bit is odd and just piles arbitrary assertion upon arbitrary
> assertion. It also suggests you know next to nothing about the chemistry
> and thermodynamics that ostensibly drives accumulation of 'prebiotic soup'.

It was a spur of the moment thought, punctuated with "might." I
hadn't thought of constant production to replace what was degraded.

Am I correct in thinking that the only thing preventing the copious
production of amino acids in the present-day earth is the oxygen in
the atmosphere and dissolved in the water? [Even if they were
produced in copious amounts, they would become food for microorganisms
in short order, wouldn't they?]

> > But I don't expect them to be easily discouraged; after all, the
> > discovery that they are alone in the galaxy is "mighty sobering" as
> > Pogo's friend Porky said at the end of an oft-quoted comment, and they
> > would want to explore (in the sense of sending "unmanned' probes for a
> > close look) an enormous number of systems before coming to such a
> > revolutionary conclusion.
>
> The motivation you ascribe to these progenitors is rather fanciful.

No more fanciful than the motivation to explore our solar system is at
the present time. We are taking our time about it, with lots of
disappointments, like the miserly funding of NASA, but I'm hoping that
in the long run, world peace will obviate the need for massive
armaments, and then we could turn to exploration in earnest.

> My bias is that it derives from some idealism rather than observation
> of what exists here.

You sure are pessimistic, aren't you?

> > Part of that exploration would consist of sending landers and orbiters
> > to the most likely planets.  At some point, they would substitute
> > micro-organisms and machines used to protect and deliver them for some
> > of the instruments, and this time the original kinds of instruments,
> > and the orbiters, would have a slightly different purpose of detecting
> > where a second seeding would be most likely to take hold and prosper.
>
> >> Based on our experience,
> >> it would span many generations. Where have we seen stable motives
> >> over say 20 generations?
> > You picked that to go to the beginning of modern science, didn't you?
>
> Not intentionally. My thinking was based on the Iroquois notion
> of the seventh generation and I just extended it 3 fold
> and then rounded.

This looks like a satire on what I am doing.

Or do you think there is something special about the musings of the
Iroquois?

Which tribe? the genocidal Mohawk nation?

> I just figured if we are that pathetically bad
> at planning just 7 generations out, tripling that would dilute
> things into total obscurity.

Plans change as circumstances change, but I think NASA is here to
stay. And then there are all those other countries exploring space to
keep some measure of competition going.

> For what it's worth, my take on the
> 7th generation is that, in the extreme, a  great grandfather
> might be able to directly tell a story to their great grandson,
> that could be someday related to a great grandson, bridging over
> 7 generations. Beyond that, linkage and motivation is too
> impersonal to have a hope. I fancy that to be an observation.

Charming, really charming, this descent into a prehistoric way of
looking to the future.

[John Harshman]

I was trying to calculate the probability that a planet's technological
life arose by native abiogenesis, which using your figures would be 1/3.

> = 100,000 * .00002 = 2.

So it is.

> And the denominator thus becomes 2+1 = 3, giving a probability of 2/3.
>
>> Yes, yes, I've already done that.
>
> You messed up by sticking to life.

Ah, yes, I forgot that there is a pT^2 factor in Tp, not just pT.

>> P(life originated on earth)= 1/(1 + [pS*N*pP]).

Should be P(intelligent, technological life arose on earth) =
1/(1 + [pS*N*pP*pT]).

>>> And this time, U * pA * pT cancels out, showing that your figure of .
>>> 0000025 for the above probability was not based on anything I wrote,
>>> inasmuch as my average figure for N was 125,000 and my figure for pP
>>> was around .5 Here is what you wrote on the "parent" thread:
>> I never presented a figure for the above probability, since you never
>> presented a formula for it. But the figure using your numbers is 1/(1 +
>> ..125 * 125,000 * .5) or 1/7813,
>
>> i.e. nearly certain that life didn't
>> originate here.
>
> You are using the wrong conditional probability. Ours isn't just any
> old planet with life; ours is a planet with a technological species on
> it.

> I do expect that for every planet like ours, there are thousands where
> the initial seeding went fine, but then for one reason or another, it
> will never progress to a technological species like ourselves.

Or would be if there were any such seeding. And that's why pT is there.

[pnyikos]

On Jun 7, 4:06�pm, John Harshman <jharsh...@pacbell.net> wrote:
> pnyikos wrote:
> > On Jun 6, 3:29 pm, John Harshman <jharsh...@pacbell.net> wrote:
> >> pnyikos wrote:
> >>> On Jun 4, 4:14 pm, John Harshman <jharsh...@pacbell.net> wrote:

> >>>> Since,
> >>>> however, you have now embraced Mark Isaak's formula, which is a ratio in
> >>>> which the probability of life cancels out, this becomes a moot question.
> >>> Not quite. �You have to replace "probability of life" with
> >>> "probability of technological civilization" to get to where anything
> >>> becomes moot.

[...]

> >>> Here is what he wrote:
> >>> pA = probability of Abiogenesis. �More specifically, the probability,
> >>> � � given an earth-like planet, of life arising to a population and
> >>> � � robustness that, short of a cosmic catastrophe, it will not go
> >>> � � extinct for millions of years at least.
> >>> pP = probability of successful Pansperia. �That is, the probability
> >>> � � that a single panspermia attempt on an earth-like planet will
> >>> � � result in life as described above.
>
> > I gave .5 here, but that was because I initially considered two probes
> > to be separate attempts. �Howevewr, all along i've been talking about
> > number of planets seeded, not number of probes sent, and so "attempt"
> > really covers up to two seedings, and my estimate now is .8.
>
> >>> pT = probability of Technological capability. �Specifically, the
> >>> � � probability that, given life as described above, it will evolve
> >>> � � and develop a race technically capable of doing panspermia.
>
> > I gave .00002 �here.
>
> >>> pS = probability, given the technical capability, that a race will
> >>> � � in fact attempt at least one panspermia seeding.
> >>> N = expected number of panspermia attempts by a race which is
> >>> attempting
> >>> � � panspermia.
>
> > My estimate for pS * N was 125, 000
>
> >> �By definition, N >= 1.
> >>> U = number of earth-like planets in the universe.

[...]

> >>> ============ end of Mark's algebraic analysis
> >>> Now let's introduce two more numbers:
> >>> Number of planets with technological species that arose via
> >>> abiogenesis on their planet:
> >>> Ta = U * pA * pT
> >>> Number of planets with technological species that arose via seeding of
> >>> their planet by panspermists:

[...]

> > Tp = U * pA * pT * pS * N * pP * pT
>
> >>> Probability that a planet's technological life arose by panspermia =
> >>> Tp / (Tp + Ta)
>
> > With U * pA * pT canceling out of both numerator and denominator, the
> > numerator becomes pS * N * pP * pT
>
> I was trying to calculate the probability that a planet's technological
> life arose by native abiogenesis, which using your figures would be 1/3.

Yes, while I was calculating the complementary probability, the one
for it arising by panspermia:

> > And the denominator thus becomes 2+1 = 3, giving a probability of 2/3.

[...]

> >> P(life originated on earth)= 1/(1 + [pS*N*pP]).
>
> Should be P(intelligent, technological life arose on earth) =
> 1/(1 + [pS*N*pP*pT]).

[...]

Yes, these two figures both have relevance:

> > I do expect that for every planet like ours, there are thousands where
> > the initial seeding went fine, but then for one reason or another, it
> > will never progress to a technological species like ourselves.
>
> Or would be if there were any such seeding.

And I believe there was: if not in our galaxy [and thus we arose by
abiogenesis that took place on earth] then elsewhere in the universe,
or if life is a once-in-a-universe-like-ours event, then in oodles of
other universes.

You see, I do believe there is a staggering number of universes, even
an enormous number like ours in all relevant respects, so that there
is plenty of opportunity for "whatever can happen, will happen".

The main alternatives are (1) that "our universe is all there is or
was or will be," and

(2) that our universe was supernaturally created.

If either of these were true, the above analysis would not hold, and
all bets would be off as to us arising by panspermia. But I think
the chance of (1) is infinitesimal, as is that of (2) in the absence
of a staggering number of universes.

If I am correct in my belief that abiogenesis resulting in even
prokaryote-level organisms is extraordinarily rare, then that makes
(1) harder to believe than it would be if abiogenesis were quite
common. This is because it seems a fantastic stroke of luck that the
one universe that could possibly have existed according to (1) should
be gifted with even one technological civilization.

We are able to ask "Why is there something rather than nothing?" If
(1) is true, but we humans had not come along, perhaps nobody and
nothing would ever be able to ask that question.

Peter Nyikos

[John Harshman]

Given enough intelligent, technological species, I agree that this would
happen occasionally. And given enough species, "occasionally" can equal
"oodles".

> The main alternatives are (1) that "our universe is all there is or
> was or will be," and

I don't see that as an alternative, actually. Our universe isn't any
different whether or not there are other universes.

> (2) that our universe was supernaturally created.
>
> If either of these were true, the above analysis would not hold, and
> all bets would be off as to us arising by panspermia.

I don't see why the existence of other universes would have any effect
whatsoever on the probability of panspermia in this universe.

> But I think
> the chance of (1) is infinitesimal, as is that of (2) in the absence
> of a staggering number of universes.

How do you calculate these chances?

> If I am correct in my belief that abiogenesis resulting in even
> prokaryote-level organisms is extraordinarily rare, then that makes
> (1) harder to believe than it would be if abiogenesis were quite
> common. This is because it seems a fantastic stroke of luck that the
> one universe that could possibly have existed according to (1) should
> be gifted with even one technological civilization.

I suppose that's true if abiogenesis has an expectation of less than
once per universe.

> We are able to ask "Why is there something rather than nothing?" If
> (1) is true, but we humans had not come along, perhaps nobody and
> nothing would ever be able to ask that question.

Weak anthropic principle.

[pnyikos]

I disagree with "occasionally", but we don't have to resolve this
particular issue any time soon in order to continue this discussion.

> And given enough species, "occasionally" can equal
> "oodles".

Yup.

> > The main alternatives are  (1) that "our universe is all there is or
> > was or will be," and
>
> I don't see that as an alternative, actually. Our universe isn't any
> different whether or not there are other universes.

You can't say "different" without at least two things to compare.
What are you comparing here?

> > (2) that our universe was supernaturally created.
>
> > If either of these were true, the above analysis would not hold, and
> > all bets would be off as to us arising by panspermia.
>
> I don't see why the existence of other universes would have any effect
> whatsoever on the probability of panspermia in this universe.

For once, I'm glad you disagree with me; it makes my short-term task
easier.

> > But I think
> > the chance of (1) is infinitesimal, as is that of (2) in the absence
> > of a staggering number of universes.
>
> How do you calculate these chances?

I think you agree with me on (2) so I'll focus on (1) this time.

(1) is just too great a stroke of luck, given some things that are in
lots less dispute than the probability of abiogenesis. Six of them
are listed by Martin Rees, Astronomer Royal, in _Just Six Numbers_, a
small excerpt from which appears here:

http://www.ichthus.info/BigBang/Docs/Just6num.pdf

It is interesting that Professor Rees prefers (3) to both (1) ["brute
fact"] and (2) ["benign Creator"], and gives a rationale for why (3)
is preferable to (1):

"These six numbers constitute a ‘recipe’ for a universe. Moreover, the
outcome is sensitive
to their values: if any one of them were to be ‘untuned’, there would
be no stars and no life. Is this
tuning just a brute fact, a coincidence? Or is it the providence of a
benign Creator? I take the view
that it is neither. An infinity of other universes may well exist
where the numbers are different.
Most would be stillborn or sterile. We could only have emerged (and
therefore we naturally now
find ourselves) in a universe with the ‘right’ combination. This
realization offers a radically new
perspective on our universe, on our place in it, and on the nature of
physical laws.

"It is astonishing that an expanding universe, whose starting point is
so ‘simple’ that it can be
specified by just a few numbers, can evolve (if these numbers are
suitable ‘tuned’) into our
intricately structured cosmos. Let us first set the scene by viewing
these structures on all scales,
from atoms to galaxies ...."

> > If I am correct in my belief that abiogenesis resulting in even
> > prokaryote-level organisms is extraordinarily rare, then that makes
> > (1) harder to believe than it would be if abiogenesis were quite
> > common.  This is because it seems a fantastic stroke of luck that the
> > one universe that could possibly have existed according to (1) should
> > be gifted with even one technological civilization.
>
> I suppose that's true if abiogenesis has an expectation of less than
> once per universe.

But see also above for why it is simply a fantastic stroke of luck
that our universe, if it is the ONLY universe, has any life in it at
all, much less intelligent life.

> > We are able to ask "Why is there something rather than nothing?"  If
> > (1) is true, but we humans had not come along, perhaps nobody and
> > nothing would ever be able to ask that question.
>
> Weak anthropic principle.

The usual use to which this principle is put is to support the
conclusion that there is nothing unusual in our seeing a tremendously
orderly universe, because intelligent beings would only be found in
such a universe in the first place.

Is that why you said what you did--to try and minimize the effect of
the paragraph to which you were responding?

Peter Nyikos

[John Harshman]

Our universe, if it's the only one, vs. our universe, if there are many
universes. In either case, the weak anthropic principle applies.

Before we get to that, let me point out that this matches none of your
hypotheses. According to Rees, very few of the universes have the
capacity for life at all. This has nothing to do with your idea that
life is improbable in a universe just like ours. In fact it makes the
multiverse not very relevant to your calculations.

Anyway, there are many physicists who disagree with Rees. I believe some
of them have come in conversation. But let me summarize. First, we don't
know the range of possible constants, i.e. we don't know the extent in
any dimension of the space of possible universes, so we can't say that
what we have here is unlikely. Second, if you vary pairs of constants
rather than single constants (ignoring the first problem), there are
many more universes that work. I believe I have used the analogy of a
line in a plane, with some non-zero slope. Change the x value, and
you're off the line; same with the y value. But there are an infinite
number of (x,y) pairs that keep you on the line. Of course in the real
space of universes the line wouldn't be infinite and would have some
thickness. But the point remains that a small change in either variable
could give you an inviable universe, while comparable changes in both
variables could give you a life-friendly universe.

>>> If I am correct in my belief that abiogenesis resulting in even
>>> prokaryote-level organisms is extraordinarily rare, then that makes
>>> (1) harder to believe than it would be if abiogenesis were quite
>>> common. This is because it seems a fantastic stroke of luck that the
>>> one universe that could possibly have existed according to (1) should
>>> be gifted with even one technological civilization.
>> I suppose that's true if abiogenesis has an expectation of less than
>> once per universe.
>
> But see also above for why it is simply a fantastic stroke of luck
> that our universe, if it is the ONLY universe, has any life in it at
> all, much less intelligent life.

Note that the prevalence or lack thereof of universes in which life is
possible says nothing about the probability of life in such universes,
which is what you are really interested in. This fine-tuning thing is
largely irrelevant to your point.

>>> We are able to ask "Why is there something rather than nothing?" If
>>> (1) is true, but we humans had not come along, perhaps nobody and
>>> nothing would ever be able to ask that question.
>> Weak anthropic principle.
>
> The usual use to which this principle is put is to support the
> conclusion that there is nothing unusual in our seeing a tremendously
> orderly universe, because intelligent beings would only be found in
> such a universe in the first place.
>
> Is that why you said what you did--to try and minimize the effect of
> the paragraph to which you were responding?

I merely point out that what you say is identical to the weak anthropic
principle. Now there are uses for that principle, and one of them is to
reduce the interest value of questions like yours. I also do not see the
relevance to our discussion.