The Pernese trans-temporal post (a proposal)
Phillip Thorne
(and her son, Todd), the titular dragons have the ability to teleport
through space -- and also time. The latter is officially discouraged
during weyrling training, but it's a key plot point in most of the
novels.
For instance, in _Dragonsblood_ (Todd McCaffrey, 2005), a sick dragon
leaps 450 years backwards (seeking an ancestor of its rider). The
high-tech ability to diagnose and bioengineer cures is rapidly fading
at the end of the First Pass, but is totally absent at the start of
the Third. The ancestors go to great lengths to engineer and conceal
a solution that won't be uncovered until the right time; they
specifically reject the notion of time-travelling to carry expertise
forward.
Wouldn't it be easier if they could rely on an established postal
system that linked the two eras?
Consider: the time-jump ability was discovered early in the First
Pass, while there are still many people with a technical imagination
and knowledge of precedents. They can establish a forward- and
back-time relay system with packet riders, with easy time-jumps of one
week, targeted using a big calendar on the side of a building.
(A similar relay was established in _Timemaster_ (Robert L. Forward,
1992) when timeholes were opened.)
Applications and advantages:
"Comet will impact in Eastern Ring Islands on (date). Tsunamis at
following coastlines. Please evacuate and pre-position relief
supplies."
"A flood occured on (date). It's a good thing you installed drainage
and moved the critical materiel out of Fort Hold's cellar."
"Plague in dragons. Samples enclosed. Please formulate cure and
return post."
Story implications:
This would of course change the nature of the stories, possibly into
something closer to _Minority Report_ (Philip K. Dick, 1956). For one
thing, it obviates all the scenes of quasi-archeological excitement.
Two-way communication with your forebears solves the biggest problem
on Pern -- loss of technical knowledge (through death of specialists
and decay of records).
And if you're sending mail, it's not a big jump to sending people. The
big point in _Dragonflight_ (Anne McCaffrey, 1968) was the transfer of
5/6 of Pern's dragon population forward 400 years. Since it's a
recurring problem that Pern's holder population resents dragonriders
as parasites during Intervals, the obvious solution is to migrate past
them. Also, there are always heavy casualties when Weyrs re-encounter
Thread for the first time each Pass, after 200 years of practicing
against rope.
Technical considerations:
Riders specify destinations to their dragons by visualization. Usually
they relay an image telepathically from someone who's seen it
first-hand, but they can alternately *imagine* a variation, such as
stellar positions or the presence of spring flowers.
"Doubling up," whereby a rider and dragon exist twice in the same
period, has no effect on dragons but causes humans to be tired and
irritable. Packet-riders should therefore spend a minimum
Riders feel ethically bound to prevent paradoxes (e.g., you can't
prevent the death of someone known to have died), but believe them to
be impossible anyway. I.e., the so-called "chronology protection
conjecture" applies.
In _Dragonsblood_, the ancestors reject the notion of sending human
aid forward in part to prevent cross-contamination (and they're
prepared to acid-sterilize any ill dragons that arrive from the
future). Appropriate sterilization and quarantine procedures can be
erected at the packet transfer stations.
--
** Phillip Thorne ** peth...@comcast.net **************
* RPI CompSci 1998 *
** underbase.livejournal.com ***************************
William December Starr
Phillip Thorne <peth...@comcast.net> said:
> "Doubling up," whereby a rider and dragon exist twice in the same
> period, has no effect on dragons but causes humans to be tired and
> irritable. Packet-riders should therefore
Have good drugs.
> spend a minimum
>
> Riders feel ethically bound to prevent paradoxes (e.g., you can't
> prevent the death of someone known to have died), but believe them
> to be impossible anyway. I.e., the so-called "chronology
> protection conjecture" applies.
Twits. You could at least _try_.
-- wds
Jerry Brown
>"chronology protection conjecture"
Wasn't this an episode title from Big Bang Theory or Middleman?
(Middleman!)
> applies.
>
>In _Dragonsblood_, the ancestors reject the notion of sending human
>aid forward in part to prevent cross-contamination (and they're
>prepared to acid-sterilize any ill dragons that arrive from the
>future). Appropriate sterilization and quarantine procedures can be
>erected at the packet transfer stations.
Jerry Brown
--
A cat may look at a king
(but probably won't bother)
<http://www.jwbrown.co.uk>
<http://www.facebook.com/JerryBrown64>
Damien Valentine
people practise it rarely. What reasons do these mysterious (and
rather callous) ancestors give when they "specifically reject the
notion of time-travelling to carry expertise forward"? As you say,
they can't be concerned with "doubling", paradox or quarantine; those
issues have already been addressed. Perhaps this method of time
travel has a high failure rate? Maybe it endangers the life, or
sanity, of either dragon or rider?
Phillip Thorne
>You say that, though they know time travel is possible and safe,
>these people practise it rarely.
Except when the plot demands it, yes. :) There's no clear overriding
reason why it *can't* be used, but like a lot of SF abilities, the
plot is destroyed if it's used to its full potential.
>What reasons do these mysterious (and
>rather callous) ancestors give when they "specifically reject the
>notion of time-travelling to carry expertise forward"?
Well, I was trying to avoid spoilers for _Dragonsblood_, but since you
asked... They specifically reject it in *this* case for two reasons:
1. There are only three people on Pern with the necessary genetic
knowledge, and it would be a one-way trip -- they're unwilling to risk
carrying the infection back. And they fear the time traveller would
fail to pick exactly the right materiel.
2. The most knowledgeable of the three is an octogenarian, and doesn't
think she'd survive the trip. (Which would mean there's an additional
physiological stress to trips /between/, beyond doubling-up, not
previously mentioned in the books.)
The physician-geneticists have a hard enough time convincing the
authorities of the era that a problem 450 years in the future, even if
it threatens the existence of Pern (it could wipe out dragonkind), is
a problem *now*.
Their solution is to build a set of rooms in Benden Weyr, stock them
with educational materials and genetic synthesis gear, hide the rooms,
and add locks that'll respond only to demonstrated understanding of
the draconic flu. Yeah, it's Rube Goldbergian, and stretches reader
disbelief in other ways.
>As you say, they can't be concerned with "doubling", paradox or
>quarantine; those issues have already been addressed.
They are *extremely* paranoid about quarantine: dissolving a dead
dragon in nitric acid and burying the remains in a pit lined with lime
is Wind Blossom's *minimal* solution.
>Perhaps this method of time travel has a high failure rate?
>Maybe it endangers the life, or sanity, of either dragon or rider?
'Fraid not. The cost (as depicted in the novels) of teleporting
(space or time) is very low. In RPG terms, it's unbalanced. It
drains the dragon-rider dyad only in extreme cases -- dozens of jumps
a day, doubling- and tripling- time jumps, jumps in rapid succession.
Competence in time-navigation *is* uncommon (Jaxom's Ruth, the white
dragon, has perfect time-sense; golds and bronzes are better than
browns, blues and greens); but since regularly dragons take direction
from a leader, that's hardly an insurmountable obstacle.
Phillip Thorne
>> "Doubling up," whereby a rider and dragon exist twice in the same
>> period, has no effect on dragons but causes humans to be tired and
>> irritable. Packet-riders should therefore
On 21 Sep 2009, wds...@panix.com (William December Starr) proposed:
>Have good drugs.
Whether there is a suitable pharmaceutical solution (like McCoy
adapting a Klingon nerve toxin to combat the psychotic effects of
spatial interphase, in ST:TOS "The Tholian Web") has never been
explored. Apparently nobody has tried that old Pernese standby,
fellis juice.
>> Riders feel ethically bound to prevent paradoxes (e.g., you can't
>> prevent the death of someone known to have died), but believe them
>> to be impossible anyway.
>
>Twits. You could at least _try_.
Characters are, at times, sorely tempted.
***
There seem to be three types of time-travel in SF:
1. Causality is inherently protected.
Pern, _Timemaster_ (Forward, 1992).
2. Changing history creates a branch universe.
Star Trek and Stargate have parallel universes, but these do not seem
to be temporal branches.
3. A single history is overwritten.
"Back to the Future," "Timothy Leary, Batu Khan, and the Palimpsest of
Universal Reality" (Flynn, 1993), "Palimpsest" (Stross, 2009), Star
Trek (sometimes), Doctor Who (sometimes), Stargate (usually).
The problem with (3) is evading the grandfather paradox so your
protagonist sticks around.
In the BttF movies, any delta has delayed effect on the agents.
In the ST:DS9 novel _Time's Enemy_ (L.A.Graf, 1996), the characters
live in dread of an oncoming future (to wit, the gunship _Defiant_
getting stuck in a comet 5000 years ago), and when they avert it,
Starfleet posits "temporal inertia" to explain why the 5000-year-old
copy of the ship doesn't evaporate.
In Stross's recent "Palimpsest," time-travel is mediated by wormhole,
and the explanation is information-theoretic: the temporary wormhole
disgorges a bolus of information -- i.e., you -- that needn't be
consistent with surrounding space-time. If you kill "your"
grandfather there is no "cause" for "you" but you're not "you" in the
usual sense -- you're just a packet of atoms that *believes* it had a
grandfather. The library at the end of time is full of "plausible
histories" that unhappened -- time-travel as Wikipedia edit-war.
(Presumably an "implausible history" would be the Earth spontaneously
splitting into three blobs of cotton candy populated by flying talking
ponies.)
Damien Valentine
> 1. There are only three people on Pern with the necessary genetic
> knowledge, and it would be a one-way trip -- they're unwilling to risk
> carrying the infection back. And they fear the time traveller would
> fail to pick exactly the right materiel.
No, there are an *infinite* number of people with the necessary
genetic knowledge, because those three can just teleport forward in
time and teach everybody else. (Or, write it all down and have
someone more expendable deliver it...such as the rider from the future
who's already right there, and plans to return.)
> 2. The most knowledgeable of the three is an octogenarian, and doesn't
> think she'd survive the trip. (Which would mean there's an additional
> physiological stress to trips /between/, beyond doubling-up, not
> previously mentioned in the books.)
But not an insurmountable one. We don't put octogenarians in F-16s
either, but young men and women do just fine. And the benefits of a
working two-way time machine far outweigh the benefits of a mere jet
fighter.
> Their solution is to build a set of rooms in Benden Weyr, stock them
> with educational materials and genetic synthesis gear, hide the rooms,
> and add locks that'll respond only to demonstrated understanding of
> the draconic flu. Yeah, it's Rube Goldbergian, and stretches reader
> disbelief in other ways.
Which means they've got a solution to their quarantine question
already. Just have the dragons teleport into a similarly sealed room,
and let their riders communicate via intercom. If for some reason
Suggestion A from Year 1, Day X doesn't work, just send the rider to
Year 1, Day Y, and let the know-it-alls chew on it a few more weeks.
Then send the rider, equipped with Suggestion B, to a point a few
seconds after the failure of Suggestion A. Wash, rinse, repeat.
> They are *extremely* paranoid about quarantine: dissolving a dead
> dragon in nitric acid and burying the remains in a pit lined with lime
> is Wind Blossom's *minimal* solution.
I didn't say anything about the solution being moderate. Though
throwing corpses in a lime-pit is damn good value for money; they
don't even have to build a Yucca Mountain for them. And again, the
benefits of a time machine far outweigh mere nuclear power. If
nuclear waste doesn't stop us from building fission reactors, chucking
a few dead dragons in a hole is not going to stop the Pernese.
Kay Shapero
bf325c...@q14g2000vbi.googlegroups.com>, vale...@gmail.com says...
> On Sep 21, 8:21=A0pm, Phillip Thorne <petho...@comcast.net> wrote:
>
> > 1. There are only three people on Pern with the necessary genetic
> > knowledge, and it would be a one-way trip -- they're unwilling to risk
> > fail to pick exactly the right materiel.
>
> No, there are an *infinite* number of people with the necessary
> genetic knowledge, because those three can just teleport forward in
> time and teach everybody else. (Or, write it all down and have
> someone more expendable deliver it...such as the rider from the future
> who's already right there, and plans to return.)
>
Actually I wonder just exactly what gives the dragons their ability to
time travel... and just what else might have, or anyway be able to use
if given, that gene complex. Fire lizards? Humans?
More closely related to the immediate discussion - as long as you've got
sapient, or nearly-so life forms about who can time travel quarantine is
not going to be nearly as secure as tracking down the origin of the
whole thing and dealing with it before any dragon ever got infected in
the first place... Same for human plagues (maybe do that first). Same
for other problems.
I'm reminded of a world I never found a story for: The resident sapient
life form discovers a way to travel in time. It is one that can be
edited into their genetic structure. They do. Dominant strain. Folks
go forward, folks go backwards, folks interbreed all the way along. A
few hundred iterations and visitors to the world will find people who
move about freely in four dimensions - and if everybody in your vicinity
suddenly vanishes, get offworld FAST because something nasty is about to
break loose...
For that matter, imagine the fun if the original Pern settlers arrive to
find a fully settled world, dragons and all.
--
Kay Shapero
address munged, email kay at following domain
http://www.kayshapero.net
Walter Bushell
Kay Shapero <k...@invalid.net> wrote:
Can't they because they didn't. Lessa could go back in time because she
did. The universe is static, time is an illusion. You can't change the
past unless you are fated to.
--
A computer without Microsoft is like a chocolate cake without mustard.
Robert Carnegie
There's a Larry Niven story... Space Emperor, let's call him, is
informed by Grand Vizier of a new scientific discovery: time machines
are possible but the universe resists them, by destroying
civilisations that try to build them, in various discreet ways:
plague, severe recession... Vizier gets to point, I think, explaining
that one prototype time machine, a vast space artifact, can be allowed
to fall into the hands of an enemy, and then the universe will destroy
the enemy. Conversation is interrupted as Emperor's own sun rather
surprisingly novas. So yes, you could try...
As for mail through time, yeah, I guess it has applications. There
are already stories about organistions that use time travel for the
benefit of civilisation (depending on your point of view) and
specifically to prevent independent time travellers interfering; also,
about organisations that communicate between parallel universes with
different histories. The plain time travel organisations are rather
liable to be written out of existence in their own stories, which
maybe I shouldn't say when it's the big surprise at the end. So
another reason to hesitate trying it in the first place.
See also James Blish's stories where Dirac radio receives all messages
that ever were or ever will be transmitted by Dirac, in the entire
universe...
Hey, about Pern, instead of colonising the planet back in time to
before the original colonists arrive from Earth, how about evacuating
all the early colonists into the time of the later books? Once again
a little problem of paradox, but isn't that what makes it interesting?
More reasonable perhaps to move the population from before Threadfall
time to after, over and over, but then how long does the ecology take
to recover after Threadfall that isn't resisted by dragonriders?
Erik Max Francis
> There's a Larry Niven story... Space Emperor, let's call him, is
> informed by Grand Vizier of a new scientific discovery: time machines
> are possible but the universe resists them, by destroying
> civilisations that try to build them, in various discreet ways:
> plague, severe recession... Vizier gets to point, I think, explaining
> that one prototype time machine, a vast space artifact, can be allowed
> to fall into the hands of an enemy, and then the universe will destroy
> the enemy. Conversation is interrupted as Emperor's own sun rather
> surprisingly novas. So yes, you could try...
"Rotating Cylinders And the Possibility of Global Causality Violation."
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
Whoever contends with the great sheds his own blood.
-- Sa'di
William George Ferguson
wrote:
>On Mon, 21 Sep 2009, Damien Valentine <vale...@gmail.com> wrote:
>>You say that, though they know time travel is possible and safe,
>>these people practise it rarely.
>
>Except when the plot demands it, yes. :) There's no clear overriding
>reason why it *can't* be used, but like a lot of SF abilities, the
>plot is destroyed if it's used to its full potential.
>
>>What reasons do these mysterious (and
>>rather callous) ancestors give when they "specifically reject the
>>notion of time-travelling to carry expertise forward"?
>
>Well, I was trying to avoid spoilers for _Dragonsblood_, but since you
>asked... They specifically reject it in *this* case for two reasons:
>
>1. There are only three people on Pern with the necessary genetic
>knowledge, and it would be a one-way trip -- they're unwilling to risk
>carrying the infection back. And they fear the time traveller would
>fail to pick exactly the right materiel.
>
>2. The most knowledgeable of the three is an octogenarian, and doesn't
>think she'd survive the trip. (Which would mean there's an additional
>physiological stress to trips /between/, beyond doubling-up, not
>previously mentioned in the books.)
The first major time jump was by Lessa in Dragonquest. She almost died (no
doubling up in a timeline involved).
When dragons go 'between' (teleport) the travel isn't instantaneous. How
long it takes depends on the 'length' of the jump, not just in space but in
time. When Lessa jumped backward 200 turns, using ht etapestry in Ruatha
Hall as her guide, she almost died of asphyxiation and hypothermia (no air
and no heat 'between'). The Lost Weyrs avoided that by coming forward in a
series of smaller jumps, but even there, some of them were pretty useless
by the time they reached the future.
Also, when Robinton went south, he went by boat, at least partly becaue the
healers didn't want him to have the stress of jumping between while
recoverng from his heart attack. (of course, he was amenable becaue it
gave him the opportunity to matchmake between Sebell and Menolly).
>>Perhaps this method of time travel has a high failure rate?
>>Maybe it endangers the life, or sanity, of either dragon or rider?
>
>'Fraid not. The cost (as depicted in the novels) of teleporting
>(space or time) is very low. In RPG terms, it's unbalanced. It
>drains the dragon-rider dyad only in extreme cases -- dozens of jumps
>a day, doubling- and tripling- time jumps, jumps in rapid succession.
Long jumps. Normally jumps on Pern, from any point to any point on the two
main continents, isn't far enough to cause an appreciable difference in the
length of the journey (Nobody seems to jump to the third continent, so we
don't have a marker for that). When F'Nor jumped to the Red Star it took
him noticeably longer (when Jaxom et alia jumped to the Dawn Sisters, in
geostationary (pernostationary?) orbit, there wasn't an appreciable time
lag, and that was likely further than to the Far Western Continent). When
jumping through time, the lag becomes noticeable at about 10 years.
As for sanity, Kylara isn't a wonderful example of time travel promoting
sanity, although you couldn't really say it made her insane, only moreso.
--
I must not fear. Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear. I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain.
(Bene Gesserit)
Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org
wrote:
> Normally jumps on Pern, from any point to any point on the two
> main continents, isn't far enough to cause an appreciable difference in the
> length of the journey (Nobody seems to jump to the third continent, so we
> don't have a marker for that). When F'Nor jumped to the Red Star it took
> him noticeably longer (when Jaxom et alia jumped to the Dawn Sisters, in
> geostationary (pernostationary?) orbit, there wasn't an appreciable time
> lag, and that was likely further than to the Far Western Continent). When
> jumping through time, the lag becomes noticeable at about 10 years.
Can we try to put a figure on the Dawn Sisters distance?
Geostationary is about 36,000 km / 22,000 miles above sea level
according to Wikipedia. Earth's radius is about 6,370 km, so it
counts significantly whether you measure distance from centre of mass
or from surface; I presume 36,000 km is the length of elevator cable
required, not counting the counterweight. (For a beanstalk, which
Pern doesn't have.) Pern is less massive, I think, but somehow has
enough atmosphere for flying dragons, or do we have to assume that
they're levitating by telepathy, and the wings are... to bang together
during mating season?
If Pern is smaller then intercontinental distances are obviously
shorter...
William December Starr
Phillip Thorne <peth...@comcast.net> said:
> In the ST:DS9 novel _Time's Enemy_ (L.A.Graf, 1996), the
> characters live in dread of an oncoming future (to wit, the
> gunship _Defiant_ getting stuck in a comet 5000 years ago), and
> when they avert it, Starfleet posits "temporal inertia" to explain
> why the 5000-year-old copy of the ship doesn't evaporate.
Because calling it "Oogie-boogie galoogie" would sound too silly,
despite being exactly as meaningful?
-- wds
William December Starr
Walter Bushell <pr...@panix.com> said:
> Kay Shapero <k...@invalid.net> wrote:
>
>> For that matter, imagine the fun if the original Pern settlers
>> arrive to find a fully settled world, dragons and all.
>
> Can't they because they didn't. Lessa could go back in time
> because she did. The universe is static, time is an illusion. You
> can't change the past unless you are fated to.
Do they rigorously test that hypothesis?
-- wds
William December Starr
Phillip Thorne <peth...@comcast.net> said:
> In Stross's recent "Palimpsest," time-travel is mediated by
> wormhole, and the explanation is information-theoretic: the
> temporary wormhole disgorges a bolus of information -- i.e., you
> -- that needn't be consistent with surrounding space-time. If you
> kill "your" grandfather there is no "cause" for "you" but you're
> not "you" in the usual sense -- you're just a packet of atoms that
> *believes* it had a grandfather.
That seems like a bit of work to explain something that doesn't need
any explaining.
A time traveler arrives in his past and -- let us assume here that
he isn't a murderer -- does something that causes his grandparents
to never meet. Despite this, he continues to exist. "But how can
this be?" asks a stunned observer. 'You don't have any origin!"
"Eh." replies the time traveler. "So I'm acausal. Big deal."
"But no effect can exist without a cause!" persists the observer.
"Well, obviously that's not true," explains the time traveler.
"Live with it. Hey, are you hungry? I could really go for some
Chinese food."
-- wds
Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org
> In article <proto-FEA462.23244622092...@news.panix.com>,
IIRC when they're planning to send dragons back in time to found a
Southern Weyr, its leader briefly visits them to say it is not going
to be a success. Before he's left to found it. They decide that this
means they're going to decide to do it anyway.
There's probably a Dilbert cartoon where much the same reasoning
process happens. I know there's one where Dilbert's future self
visits him... but I don't believe it's during a meeting...
Incidentally, in kid superhero school comic P.S. 238 there's a time
traveller shapeshifter character whose function is, to prevent paradox
situations happening, when you travel in time and meet yourself or
somone you know, or when /they/ travel in time, it's not really who it
appears to be, it's this guy standing in. I suppose not every time,
but often.
Patok
following:
- static time-space; nothing a traveler does changes anything, because
whatever will happen, already has. In this model, time-travelers can't
kill their early selves. This one is internally consistent
- dynamic time-space. Travelers can and do produce paradoxes. It is up
to somebody else to fix them, if fixed they be. When travelers change
history, entire timelines, people and facts, simply vanish. This one has
the inherent problem of how to detect the change and fix it.
- onion-ring time-space. Time travel goes into a different universe.
Essentially, you can't change your own past or future - they're somebody
else's. The past and future of one's own universe don't exist on a
physical level, and can't be visited; there's only the 'now'.
- others?
I think that number two is the most widely used, because it offers the
author the greatest freedom in improvising situations and interactions,
but is on the other hand almost impossible to do right, without
contradictions and paradoxes. And I don't think I've read many books
with number three - only Simak's "All flesh is grass" comes to mind.
Phillip Thorne wrote:
> In the long-running "Dragonriders of Pern" series by Anne McCaffrey
> (and her son, Todd), the titular dragons have the ability to teleport
> through space -- and also time. The latter is officially discouraged
> during weyrling training, but it's a key plot point in most of the
> novels.
>
--
You'd be crazy to e-mail me with the crazy. But leave the div alone.
David Johnston
wrote:
>What models of time travel do we see in literature? I can think of the
>following:
>
>- static time-space; nothing a traveler does changes anything, because
>whatever will happen, already has. In this model, time-travelers can't
>kill their early selves. This one is internally consistent
And totally eliminates the illusion of free will.
>
>- dynamic time-space. Travelers can and do produce paradoxes. It is up
>to somebody else to fix them, if fixed they be. When travelers change
>history, entire timelines, people and facts, simply vanish. This one has
>the inherent problem of how to detect the change and fix it.
Usually handled by the Time Traveller's Immunity Clause.
>
>- onion-ring time-space. Time travel goes into a different universe.
>Essentially, you can't change your own past or future - they're somebody
>else's. The past and future of one's own universe don't exist on a
>physical level, and can't be visited; there's only the 'now'.
>
>- others?
There is of course the one where time travel spawns a different
universe.
>
>I think that number two is the most widely used, because it offers the
>author the greatest freedom in improvising situations and interactions,
>but is on the other hand almost impossible to do right, without
>contradictions and paradoxes.
Assuming of course you labour under the impression that the right way
to do time travel is without paradoxes.
Patok
> On Wed, 23 Sep 2009 13:44:13 -0400, Patok <crazy.d...@gmail.com>
> wrote:
>
>> What models of time travel do we see in literature? I can think of the
>> following:
>>
>> - static time-space; nothing a traveler does changes anything, because
>> whatever will happen, already has. In this model, time-travelers can't
>> kill their early selves. This one is internally consistent
>
> And totally eliminates the illusion of free will.
Well, as it is an illusion anyway, I don't see anything wrong with
that. :)
>> - dynamic time-space. Travelers can and do produce paradoxes. It is up
>> to somebody else to fix them, if fixed they be. When travelers change
>> history, entire timelines, people and facts, simply vanish. This one has
>> the inherent problem of how to detect the change and fix it.
>
> Usually handled by the Time Traveller's Immunity Clause.
What I meant was how do the others detect it (like time cops and
suchlike). The only realistic case seems to be when the travelers
themselves alone detect and fix changes.
>
>> - onion-ring time-space. Time travel goes into a different universe.
>> Essentially, you can't change your own past or future - they're somebody
>> else's. The past and future of one's own universe don't exist on a
>> physical level, and can't be visited; there's only the 'now'.
>>
>> - others?
>
> There is of course the one where time travel spawns a different
> universe.
I was thinking of including it, but it seemed to me that it is a
particular case of either number two or number three, depending on point
of view.
>> I think that number two is the most widely used, because it offers the
>> author the greatest freedom in improvising situations and interactions,
>> but is on the other hand almost impossible to do right, without
>> contradictions and paradoxes.
>
> Assuming of course you labour under the impression that the right way
> to do time travel is without paradoxes.
If it pretends to be scientifically realistic, it must.
Entertainment value is, of course, a different aspect altogether.
Butch Malahide
> What models of time travel do we see in literature? I can think of the
> following:
> - onion-ring time-space. Time travel goes into a different universe.
> Essentially, you can't change your own past or future - they're somebody
> else's. The past and future of one's own universe don't exist on a
> physical level, and can't be visited; there's only the 'now'.
>
> - others?
>
> I think that number two is the most widely used, because it offers the
> author the greatest freedom in improvising situations and interactions,
> but is on the other hand almost impossible to do right, without
> contradictions and paradoxes. And I don't think I've read many books
> with number three - only Simak's "All flesh is grass" comes to mind.
_The Empire of Time_ by Crawford Kilian.
http://www.isfdb.org/cgi-bin/title.cgi?3026
David Johnston
wrote:
>> There is of course the one where time travel spawns a different
>> universe.
>
> I was thinking of including it, but it seemed to me that it is a
>particular case of either number two or number three, depending on point
>of view.
In the end everything is a special case of either you can do it, or
you can't.
>
>
>>> I think that number two is the most widely used, because it offers the
>>> author the greatest freedom in improvising situations and interactions,
>>> but is on the other hand almost impossible to do right, without
>>> contradictions and paradoxes.
>>
>> Assuming of course you labour under the impression that the right way
>> to do time travel is without paradoxes.
>
> If it pretends to be scientifically realistic, it must.
Scientific "realism" would require recognising that attempts to change
history are invitable and figuring out what would happen when people
tried. The only good approach to that I've ever seen involves the
time travel not being under the control of the people doing i t.
Erik Max Francis
> What models of time travel do we see in literature? I can think of the
> following:
>
> - static time-space; nothing a traveler does changes anything, because
> whatever will happen, already has. In this model, time-travelers can't
> kill their early selves. This one is internally consistent
>
> - dynamic time-space. Travelers can and do produce paradoxes. It is up
> to somebody else to fix them, if fixed they be. When travelers change
> history, entire timelines, people and facts, simply vanish. This one has
> the inherent problem of how to detect the change and fix it.
>
> - onion-ring time-space. Time travel goes into a different universe.
> Essentially, you can't change your own past or future - they're somebody
> else's. The past and future of one's own universe don't exist on a
> physical level, and can't be visited; there's only the 'now'.
>
> - others?
>
> I think that number two is the most widely used, because it offers the
> author the greatest freedom in improvising situations and interactions,
> but is on the other hand almost impossible to do right, without
> contradictions and paradoxes. And I don't think I've read many books
> with number three - only Simak's "All flesh is grass" comes to mind.
Many years ago I posted a classification of time travel rationalizations
used in science fiction. It was pretty much the same as Phillip's: 1.
causality is protected (which doesn't necessarily mean time travel is
impossible, just that somehow consistency is enforced); 2. time travel
spins you off into a different "timeline," which doesn't affect other
timelines; and 3. there's one timeline but there's a form of "metatime,"
where changes somehow take this "metatime" to propagate. This is
awfully common in the more popularized science fiction such as _Back to
the Future_, though it probably makes the least sense.
Obviously you could add the case where time travel is fundamentally
impossible, but then that doesn't really change much.
Recently Sean Carroll posted a blog post (which I linked to here)
outlining the set of restrictions on time travel that would have to be
imposed by the laws of physics as we currently understand them. It
basically boils down to case 1 above; if time travel is possible, then
you can't have closed loops or change the past, as what has happened has
already happened and cannot be changed.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
No one should have to dance backward all their lives.
-- Jill Ruckelshaus
Erik Max Francis
> That seems like a bit of work to explain something that doesn't need
> any explaining.
>
> A time traveler arrives in his past and -- let us assume here that
> he isn't a murderer -- does something that causes his grandparents
> to never meet. Despite this, he continues to exist. "But how can
> this be?" asks a stunned observer. 'You don't have any origin!"
>
> "Eh." replies the time traveler. "So I'm acausal. Big deal."
>
> "But no effect can exist without a cause!" persists the observer.
>
> "Well, obviously that's not true," explains the time traveler.
> "Live with it. Hey, are you hungry? I could really go for some
> Chinese food."
Well, the total lack of logical consistency is arguably a pretty serious
problem. In terms of suspension of disbelief, perhaps the issue won't
present itself in an individual story. But if you want to take such
things seriously, you'll end up exploring the boundary conditions and
weird edge cases inevitable, even in the fictional world itself.
alien8er
> What models of time travel do we see in literature? I can think of the
> following:
(snip)
> - others?
There's "Ian Wallace's" Croyd Spacetime Maneouvres series. Croyd is
an almost-human who can, among other things, travel in time but only
to the past (the future doesn't exist yet, so trying to travel
forwards just gets you lost).
When he travels into the past it's only for observational purposes;
he can change nothing. Also he cannot get in the way of anything
moving because objects in the past are "denser" the farther back he
goes; he'd be squished by contact.
How air molecules don't shred him is not addressed.
I'm failing to recall the general story line in one of Laumer's
tales; the detail I can recall is that when one character (the
protag?) travels back in time he has causality issues; he does so in
reverse, and appears to those in the past to be a man on fire. Also,
when traveling backwards, he can see because "light is a condition,
not an event".
Mark L. Fergerson
David Johnston
wrote:
>
>Recently Sean Carroll posted a blog post (which I linked to here)
>outlining the set of restrictions on time travel that would have to be
>imposed by the laws of physics as we currently understand them. It
>basically boils down to case 1 above; if time travel is possible, then
>you can't have closed loops or change the past, as what has happened has
>already happened and cannot be changed.
Which is not in fact a law of physics until tested by experiment.
Since time travel is probably impossible in any meaningful sense,
that's probably not going to happen. The Novikov Self-Consistency
Conjecture is just a statement of how he wants the universe to work
but there's no explanation of what enforces it.
Howard Brazee
wrote:
>> "Well, obviously that's not true," explains the time traveler.
>> "Live with it. Hey, are you hungry? I could really go for some
>> Chinese food."
>
>Well, the total lack of logical consistency is arguably a pretty serious
>problem. In terms of suspension of disbelief, perhaps the issue won't
>present itself in an individual story. But if you want to take such
>things seriously, you'll end up exploring the boundary conditions and
>weird edge cases inevitable, even in the fictional world itself.
The trouble is, we assume that everything has to have a cause - but we
have no way of testing this assumption. It is a useful assumption to
make, as long as we stay away from theology.
With time travel, we are already throwing away causality. So why not
have experiments like Heinlein's two stories, or Gerrald's novel, or
Bradbury's story, or Tenn's story? We can't say that one set of
assumptions is right and another's is wrong. None of them fit our
(untested) assumptions about causality.
--
"In no part of the constitution is more wisdom to be found,
than in the clause which confides the question of war or peace
to the legislature, and not to the executive department."
- James Madison
Howard Brazee
wrote:
>- static time-space; nothing a traveler does changes anything, because
>whatever will happen, already has. In this model, time-travelers can't
>kill their early selves. This one is internally consistent
>
>- dynamic time-space. Travelers can and do produce paradoxes. It is up
>to somebody else to fix them, if fixed they be. When travelers change
>history, entire timelines, people and facts, simply vanish. This one has
>the inherent problem of how to detect the change and fix it.
>
>- onion-ring time-space. Time travel goes into a different universe.
>Essentially, you can't change your own past or future - they're somebody
>else's. The past and future of one's own universe don't exist on a
>physical level, and can't be visited; there's only the 'now'.
Time travel changes everything except the traveler (Bradbury).
Time travel changes everything except the reader (Tenn).
Howard Brazee
wrote:
>- dynamic time-space. Travelers can and do produce paradoxes. It is up
>to somebody else to fix them, if fixed they be. When travelers change
>history, entire timelines, people and facts, simply vanish. This one has
>the inherent problem of how to detect the change and fix it.
This one bothers me. It allows for some conflict, but it means that
minor changes don't matter.
Wayne Throop
: The Novikov Self-Consistency
: Conjecture is just a statement of how he wants the universe to work
: but there's no explanation of what enforces it.
What, the likelyhood that any method of causally affecting anything in
your own past lightcone will end up creating a closed lightlike curve,
which will in turn destroy whatever it was that was trying to get
into the pastward lightcone (or was tryng to create a path to do so)
is "no explanation"? What *would* count as an explanation?
Wayne Throop thr...@sheol.org http://sheol.org/throopw
David Johnston
wrote:
Doesn't that just mean time travel is impossible?
Erik Max Francis
> On Wed, 23 Sep 2009 13:44:13 -0400, Patok <crazy.d...@gmail.com>
> wrote:
>
>> What models of time travel do we see in literature? I can think of the
>> following:
>>
>> - static time-space; nothing a traveler does changes anything, because
>> whatever will happen, already has. In this model, time-travelers can't
>> kill their early selves. This one is internally consistent
>
> And totally eliminates the illusion of free will.
Perhaps, perhaps not (if indeed there really is such a thing as free
will, a subject which often has seemed like philosophical mental
masturbation to me). What it does mean is that if you deliberately try
to go back in time and screw with things in sufficiently naughty ways,
something will stop you. That doesn't _necessarily_ mean that you can't
travel back in time and mess with things at all, as long as you actually
did that in the past.
Mike Ash
Erik Max Francis <m...@alcyone.com> wrote:
> 3. there's one timeline but there's a form of "metatime,"
> where changes somehow take this "metatime" to propagate. This is
> awfully common in the more popularized science fiction such as _Back to
> the Future_, though it probably makes the least sense.
It makes perfect sense. Metatime is just time as measured by clocks
residing outside of the television rather than inside.
The only remaining question is how we can get access to clocks outside
our TV so we can tell what's going on when we start traveling through
time.
--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon
Erik Max Francis
> There's "Ian Wallace's" Croyd Spacetime Maneouvres series. Croyd is
> an almost-human who can, among other things, travel in time but only
> to the past (the future doesn't exist yet, so trying to travel
> forwards just gets you lost).
>
> When he travels into the past it's only for observational purposes;
> he can change nothing. Also he cannot get in the way of anything
> moving because objects in the past are "denser" the farther back he
> goes; he'd be squished by contact.
>
> How air molecules don't shred him is not addressed.
Also apparently why he's not supposed to be able to change things but
still absorbs photons to see anything. Otherwise he wouldn't be able to
detect anything -- but that certainly changes things.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
Chastity the most unnatural of the sexual perversions.
-- Aldous Huxley
David Johnston
wrote:
>David Johnston wrote:
>> On Wed, 23 Sep 2009 13:44:13 -0400, Patok <crazy.d...@gmail.com>
>> wrote:
>>
>>> What models of time travel do we see in literature? I can think of the
>>> following:
>>>
>>> - static time-space; nothing a traveler does changes anything, because
>>> whatever will happen, already has. In this model, time-travelers can't
>>> kill their early selves. This one is internally consistent
>>
>> And totally eliminates the illusion of free will.
>
>Perhaps, perhaps not (if indeed there really is such a thing as free
>will, a subject which often has seemed like philosophical mental
>masturbation to me). What it does mean is that if you deliberately try
>to go back in time and screw with things in sufficiently naughty ways,
>something will stop you.
To which the question is always "what"?
Robert Carnegie
to intervene in historical events and change them as ordered by
mysterious commanders, as in
<http://en.wikipedia.org/wiki/The_Big_Time>
- oh,hey, here's tentacled moon-people who blew up their world to
leave it in the condition we see now - anyway, in that world's physics
(in other stories), making small changes in the past doesn't work,
because they are ironed out. One story explains that soldiers are
"recruited" by being snatched from reality around the moment of their
violent death, copied really, and one recruit tries over and over to
prevent his own death (which they aren't normally allowed to do) and
the original events keep reinstating themselves. And yet major
changes are possible. Maybe it's like changing the course of a river,
move one drop of water and it just goes back to how it was.
Slightly related concept - in the comics and in some Star Trek,
parallel universes exist and influence each other's history, so Star
Trek's "mirror universe" initially has a duplicate evil Starship
Enterprise and crew who presumably consider themselves the real thing
and the regular show cast the copies. there are some differences but
major personnel are the same, and one way to make sense of that is to
say something like, history leaks from one universe into others.
In the comics, changing history radically or visiting a parallel
universe is liable to show you a world with different history but
where the major comics characters still exist - you know, Superman,
Batman, Spider-Man. Not always guaranteed, though. And usually
history is restored to the original version, but there are exceptions
- DC Comics has recreated its universe several times now while
installing most of the original characters,some not even noticing the
changes; Spider-Man has done something creepy involving magic so now
he was never married - and some parallel universes have a long-term
existence while incorporating versions of major trademark characters.
For instance there's a year 2099 Spider-Man - revised one or more
times himself, in fact - and another independent Ultimate Spider-Man.
There must be some really strange physics behind this. The Fantastic
Four once visited God and they perceived him as a comics writer and
artist who received them in his working office...
And then there's
<http://everything2.com/title/The+Men+Who+Murdered+Mohammed>
whose story title seems to be chosen for the alliteration as well as
the evident magnitude of the action.
Erik Max Francis
> On Wed, 23 Sep 2009 13:44:13 -0400, Patok <crazy.d...@gmail.com>
> wrote:
>
>> - dynamic time-space. Travelers can and do produce paradoxes. It is up
>> to somebody else to fix them, if fixed they be. When travelers change
>> history, entire timelines, people and facts, simply vanish. This one has
>> the inherent problem of how to detect the change and fix it.
>
> This one bothers me. It allows for some conflict, but it means that
> minor changes don't matter.
It also would suggest Niven's law on time travel: Unrestricted time
travel that really can change the past, cause paradoxes, etc. suggests
an unstable state. It's not unreasonable to conclude that eventually
this will have to settle down to a stable state, and the only way that
can happen is if no time travel machine ever gets invented or, if
invented, used.
Erik Max Francis
Sounds like you're mixing up two things; you sound like a (plausible)
explanation for what would enforce the cosmic censorship conjecture,
which is separate from the self-consistency conjecture. The former
asserts that time machines aren't allowed; the latter merely asserts
that time travel, if possible, does not allow paradoxes.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
Wayne Throop
::: he wants the universe to work but there's no explanation of what
::: enforces it.
:: What, the likelyhood that any method of causally affecting anything
:: in your own past lightcone will end up creating a closed lightlike
:: curve, which will in turn destroy whatever it was that was trying to
:: get into the pastward lightcone (or was tryng to create a path to do
:: so) is "no explanation"? What *would* count as an explanation?
: David Johnston <da...@block.net>
: Doesn't that just mean time travel is impossible?
No. It's a description of a mechanism.
Any conclusion based on it that time travel is impossible
is just that, a conclusion based on it. Which is just what
was asked for, ie, an "expalanation of what enforces it".
It's a vague, handwavy description/explanation, but it *is* one.
Wayne Throop
: Doesn't that just mean time travel is impossible?
Oops, in my previous two messages in this subthread, I was mistaking
which conjecture you were talking about. You clearly said "consistency",
I kept hearing "chronology protection". So, rewinding those two...
:::: The Novikov Self-Consistency Conjecture is just a statement of how
:::: he wants the universe to work but there's no explanation of what
:::: enforces it.
But isn't it enough to suppose that there's no meta-time and no alternate
timelines? If your time travel produced a change, then that would imply
that there's a meta-time. At a small touch of quantum indeterminacy,
to provide some jiggle, and basically if everything wasn't unchanging,
things would inevitably jiggle until it *was* unchanging.
Or, look at it as a causal loop. If the events along it aren't stable,
it's going to evaporate.
Now, one could suppose there's a bistable state. A loop that has one
outcome (you get born, decide to kill your grandfather) alternating
with another outcome (you don't get born, and so don't decide to kill
your grandfather). In which case, absent meta-time, you'd have a
macroscopic object in a superposition of states (eg, your grandfather,
schroedinger-cat-like, both alive and dead), and a macroscopic object's
wave function always collapses into a single state (more or less).
So like I say, isn't it enough to suppose there's no meta-time?
Well, and no alternate timelines so that it can't be two objects
on a bifurcated timeline?
Or, put another way, what do you count as the mechanism that causes
wave functions to so consistently collapse and the universe to
appear non-quantum-mechanical at macroscopic scales, and why wouldn't
the same mechanism work for this?
Ted Nolan <tednolan>
In the Cryod books (and I highly recommend the first two: _Croyd_ & _Dr.
Orpheus_) going into the past is referred to as going "uptime" since you
are going against the flow of time. In Dr. Orpheus, the titular character
does something (a drug inhibiting Free Will maybe?) that causes Erth's
"present" to stretch out for decades into the future -- things are so
completely determined that you can visit it.
In Wallace's _Pan Sagittarius_, Croyd's brother Pan discovers the "if nodes
of antan" a feature of uptime such that if you take souls uptime and put
them back into their bodies (which are otherwise just automatons, their
souls and will having flowed forward with the "present") the soul can
make new decisions and come to new realizations though it still can't, I think,
change uptime events.
Really weird series. Two strong books, and the rest going off in completely
other directions and IMHO way downhill.
Ted
--
------
columbiaclosings.com
What's not in Columbia anymore..
Ted Nolan <tednolan>
Robert Carnegie <rja.ca...@excite.com> wrote:
>
>Slightly related concept - in the comics and in some Star Trek,
>parallel universes exist and influence each other's history, so Star
>Trek's "mirror universe" initially has a duplicate evil Starship
>Enterprise and crew who presumably consider themselves the real thing
>and the regular show cast the copies. there are some differences but
>major personnel are the same, and one way to make sense of that is to
>say something like, history leaks from one universe into others.
>
I don't see that that's necessary. Perhaps out of the infinite number
of parallel universes, it's simply easier to travel to the ones which
have a high correlation to one's own.
Lawrence Watt-Evans
wrote:
>It also would suggest Niven's law on time travel: Unrestricted time
>travel that really can change the past, cause paradoxes, etc. suggests
>an unstable state. It's not unreasonable to conclude that eventually
>this will have to settle down to a stable state, and the only way that
>can happen is if no time travel machine ever gets invented or, if
>invented, used.
Why would it settle down to a stable state, though?
--
My webpage is at http://www.watt-evans.com
I'm selling my comic collection -- see http://www.watt-evans.com/comics.html
I'm serializing a novel at http://www.watt-evans.com/realmsoflight0.html
Kay Shapero
says...
> >
> > For that matter, imagine the fun if the original Pern settlers arrive to
> > find a fully settled world, dragons and all.
>
> Can't they because they didn't. Lessa could go back in time because she
> did. The universe is static, time is an illusion. You can't change the
> past unless you are fated to.
>
Gee, that's no fun. I stopped reading the series about the time Todd
came on board as it had started tying itself up in knots - have the
Pernese tested that hypothesis? Rigorously? In which book? I may go
read that one.
--
Kay Shapero
address munged, email kay at following domain
http://www.kayshapero.net
Butch Malahide
>
> In the Cryod books (and I highly recommend the first two: _Croyd_ & _Dr.
> Orpheus_) going into the past is referred to as going "uptime" since you
> are going against the flow of time.
And so this boring thread spawns an interesting scientiphilological
question: which way is "uptime" (and "downtime") in stf, generally
speaking?
Uptime = pastward:
1. Ian Wallace, _Croyd_ etc.
Uptime = futureward:
1. Poul Anderson, _There Will Be Time_ etc.
2. Crawford Kilian, _The Empire of Time_
So far, it's 2 to 1 in favor of uptime = futurward & downtime =
pastward. Any other examples? I couldn't find "uptime" or "downtime"
in Silverberg's _Up the Line_, though I wouldn't bet my house they
aren't there; if they *were* there, presumably "uptime" would mean
"pastward", i.e. "up the line".
Bill Snyder
I always favored uptime being the past by analogy with
upstream/downstream; but naming them the other way 'round seems to
be more common. Always gives me a mental jolt.
--
Bill Snyder [This space unintentionally left blank]
Butch Malahide
> On Thu, 24 Sep 2009 00:03:12 -0700 (PDT), Butch Malahide
>
>
>
>
>
> <fred.gal...@gmail.com> wrote:
> >On Sep 23, 9:40 pm, t...@loft.tnolan.com (Ted Nolan <tednolan>) wrote:
>
> >> In the Cryod books (and I highly recommend the first two: _Croyd_ & _Dr.
> >> Orpheus_) going into the past is referred to as going "uptime" since you
> >> are going against the flow of time.
>
> >And so this boring thread spawns an interesting scientiphilological
> >question: which way is "uptime" (and "downtime") in stf, generally
> >speaking?
>
> >Uptime = pastward:
> >1. Ian Wallace, _Croyd_ etc.
>
> >Uptime = futureward:
> >1. Poul Anderson, _There Will Be Time_ etc.
> >2. Crawford Kilian, _The Empire of Time_
>
> >So far, it's 2 to 1 in favor of uptime = futurward & downtime =
> >pastward. Any other examples? I couldn't find "uptime" or "downtime"
> >in Silverberg's _Up the Line_, though I wouldn't bet my house they
> >aren't there; if they *were* there, presumably "uptime" would mean
> >"pastward", i.e. "up the line".
>
> I always favored uptime being the past by analogy with
> upstream/downstream;
I tend to agree with you, though thinking of an archeological dig
suggests the opposite. However, my question is about what the
prevailing usage *is*, not what it ought to be; maybe I wasn't clear
on that. This comes from my interest in the OED science fiction
project.
> but naming them the other way 'round seems to
> be more common.
I guess so, but that's what I'm trying to find out. So I'd appreciate
pointers to any other stf authors using the terms "uptime" and/or
"downtime".
Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org
> On Wed, 23 Sep 2009 17:09:18 -0700, Erik Max Francis <m...@alcyone.com>
> wrote:
>
>
>
>
>
> >David Johnston wrote:
> >> wrote:
>
> >>> What models of time travel do we see in literature? I can think of the
> >>> following:
>
> >>> - static time-space; nothing a traveler does changes anything, because
> >>> whatever will happen, already has. In this model, time-travelers can't
> >>> kill their early selves. This one is internally consistent
>
> >> And totally eliminates the illusion of free will.
>
> >Perhaps, perhaps not (if indeed there really is such a thing as free
> >will, a subject which often has seemed like philosophical mental
> >masturbation to me). What it does mean is that if you deliberately try
> >to go back in time and screw with things in sufficiently naughty ways,
> >something will stop you.
>
> To which the question is always "what"?
Well, in an unchangeable past physics, you can only say that something
evidently did. You know your paternal grandfather wasn't murdered
before your father wasconceived, so if you or somebody else were in
the past by time machine, plotting to murder your grandfather,
evidently they failed.
But let me offer another paradox. Suppose that you know that a future
you travels back in time and saved your grandfather's life before your
father was conceived; if future you hadn't been there, your
grandfather would have died. Can you now choose not to travel back in
time to do that? This time it isn't using a time machine that breaks
reality, it is /not/ using a time machine.
Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org
We're crossposting with rec.arts.sf.science, so I think we can say
that is a formal theory and an u&testable one - unless it can be
tested on the quantum mechanical scale and scope of nature, where
cause and effect and where and, perhaps, when, are not rigid
realities, and where, perhaps, you can construct real causality
violation experiments.
By "destroy whatever it was that was trying to get into the pastward
lightcone", do you mean that an H. G. Wells time machine will blow up
before it leaves the present time? Or blow up as soon as it arrives
in the past? In the latter case, merely the means to send bombs into
history could be militarily useful. Although I'm having trouble
thinking of ways to use it without breaching the Geneva Conventions or
international law. If you bomb an enemy soldier the day before he
joined up, for instance, then you hit a civilian. Or if you send an
attack back in time to before you were at war with the enemy, that's
worse.
Robert Carnegie: Fnord: cc talk-origins@moderators.isc.org
> In article <c49ee31f-9e27-4c51-9102-57eb47afa...@h30g2000vbr.googlegroups.com>,
> Robert Carnegie <rja.carne...@excite.com> wrote:
>
>
>
> >Slightly related concept - in the comics and in some Star Trek,
> >parallel universes exist and influence each other's history, so Star
> >Trek's "mirror universe" initially has a duplicate evil Starship
> >Enterprise and crew who presumably consider themselves the real thing
> >and the regular show cast the copies. there are some differences but
> >major personnel are the same, and one way to make sense of that is to
> >say something like, history leaks from one universe into others.
>
> I don't see that that's necessary. Perhaps out of the infinite number
> of parallel universes, it's simply easier to travel to the ones which
> have a high correlation to one's own.
But how is correlation defined? In physics you'd expect it to start
with individual sub-atomic particles, or else big things like
supermassive black holes, and the easiest parallel universes to visit
would be practically indistinguishable from your own. Maybe they are
and we all flip between minutely different universes without ever
knowing. But why isn't a universe where Captain Archer keeps a cat
instead of a dog more easily found than one where Captain Archer and
his crew are all space Nazis? Maybe the dog-cat type stories are just
the ones they don't bother to film?
George W Harris
talk-o...@moderators.isc.or�g <rja.ca...@excite.com> wrote:
>
>But let me offer another paradox. Suppose that you know that a future
>you travels back in time and saved your grandfather's life before your
>father was conceived; if future you hadn't been there, your
>grandfather would have died. Can you now choose not to travel back in
>time to do that? This time it isn't using a time machine that breaks
>reality, it is /not/ using a time machine.
It will turn out that it wasn't future you
after all, but someone else. Or, circumstances
will conspire to force you to go back in time and
save him afterall.
--
Doesn't the fact that there are *exactly* 50 states seem a little suspicious?
George W. Harris For actual email address, replace each 'u' with an 'i'
David Johnston
talk-o...@moderators.isc.or�g <rja.ca...@excite.com> wrote:
Obviously you would fail at not doing anything. The divine
scriptwriter would puppet you into the time machine no matter what.
Which is why unchangeable pasts combined with time travel under your
control equal no freedom of will.
Mad Hamish
In the Nantucket series the people who go back in time are the
uptimers.
Mike Ash
<2avlb5h4npgc44ipt...@news.eternal-september.org>,
Lawrence Watt-Evans <l...@sff.net> wrote:
> On Wed, 23 Sep 2009 17:27:59 -0700, Erik Max Francis <m...@alcyone.com>
> wrote:
>
> >It also would suggest Niven's law on time travel: Unrestricted time
> >travel that really can change the past, cause paradoxes, etc. suggests
> >an unstable state. It's not unreasonable to conclude that eventually
> >this will have to settle down to a stable state, and the only way that
> >can happen is if no time travel machine ever gets invented or, if
> >invented, used.
>
> Why would it settle down to a stable state, though?
I figure there are three possibilities:
1) It encounters a stable state, then stays there.
2) It encounters a set of states arranged in a cycle, each one leading
to the next.
3) There are an infinite number of possible states, and it never cycles
or remains on one.
#2 and #3 seem improbable but there's nothing to really prevent it that
I can see. One has to wonder what it looks like being in a universe that
exhibits #2 or #3 though.
Michael Stemper
> I'm failing to recall the general story line in one of Laumer's
>tales; the detail I can recall is that when one character (the
>protag?) travels back in time he has causality issues; he does so in
>reverse, and appears to those in the past to be a man on fire.
Are you sure that you're not thinking of Bester? When the protag in
_Tiger, Tiger_ (_The Stars My Destination_) jaunts backwards in time,
he's observed as "the burning man".
--
Michael F. Stemper
#include <Standard_Disclaimer>
2 + 2 = 5, for sufficiently large values of 2
Remus Shepherd
> > I'm failing to recall the general story line in one of Laumer's
> >tales; the detail I can recall is that when one character (the
> >protag?) travels back in time he has causality issues; he does so in
> >reverse, and appears to those in the past to be a man on fire.
> Are you sure that you're not thinking of Bester? When the protag in
> _Tiger, Tiger_ (_The Stars My Destination_) jaunts backwards in time,
> he's observed as "the burning man".
I'd have to check TSMD to make sure, but as I recall when he jaunted
backwards in time he actually *was* on fire.
... ...
Remus Shepherd <re...@panix.com>
Journal: http://www.livejournal.com/users/remus_shepherd/
alien8er
Nah, it was only somebody else who looks just like you. Oh, wait,
this is post-CSI, so they'd have your DNA too.
Sheer coincidence.
Mark L. Fergerson
GSV Three Minds in a Can
Remus Shepherd <re...@panix.com> said
>In rec.arts.sf.written Michael Stemper <mste...@walkabout.empros.com> wrote:
>> > I'm failing to recall the general story line in one of Laumer's
>> >tales; the detail I can recall is that when one character (the
>> >protag?) travels back in time he has causality issues; he does so in
>> >reverse, and appears to those in the past to be a man on fire.
>
>> Are you sure that you're not thinking of Bester? When the protag in
>> _Tiger, Tiger_ (_The Stars My Destination_) jaunts backwards in time,
>> he's observed as "the burning man".
>
> I'd have to check TSMD to make sure, but as I recall when he jaunted
>backwards in time he actually *was* on fire.
Correct - he's already seen himself on the steps before he jaunted back
there, which he did from the explosion when the PK-detonated-explosive
residues were set off. He jaunted to several 'been there already' places
IIRC.
--
GSV Three Minds in a Can
15,621 Km walked. 2,882 Km PROWs surveyed. 52.1% complete.
Michael Stemper
>In rec.arts.sf.written Michael Stemper <mste...@walkabout.empros.com> wrote:
>> >tales; the detail I can recall is that when one character (the
>> >protag?) travels back in time he has causality issues; he does so in
>> >reverse, and appears to those in the past to be a man on fire.
>
>> Are you sure that you're not thinking of Bester? When the protag in
>> _Tiger, Tiger_ (_The Stars My Destination_) jaunts backwards in time,
>> he's observed as "the burning man".
>
> I'd have to check TSMD to make sure, but as I recall when he jaunted
>backwards in time he actually *was* on fire.
Yeah, he was.
--
Michael F. Stemper
#include <Standard_Disclaimer>
Indians scattered on dawn's highway bleeding;
Ghosts crowd the young child's fragile eggshell mind.
Wayne Throop
: In the Nantucket series the people who go back in time are the
: uptimers.
Are they called that because of when they came from,
or because of when they went to?
alien8er
wrote:
> In article <accf2593-1f8e-4e8c-b654-476a0c2a1...@y10g2000prg.googlegroups.com>, alien8er <alien8...@gmail.com> writes:
>
> > I'm failing to recall the general story line in one of Laumer's
> >tales; the detail I can recall is that when one character (the
> >protag?) travels back in time he has causality issues; he does so in
> >reverse, and appears to those in the past to be a man on fire.
>
> Are you sure that you're not thinking of Bester? When the protag in
> _Tiger, Tiger_ (_The Stars My Destination_) jaunts backwards in time,
> he's observed as "the burning man".
No, I don't think so; I specifically recall the reverse time-travel
and being on fire thing in conjunction with light being "a condition,
not an event". Laumer used that last gimmick twice, once in
_Imperium_:
which isn't the example I was thinking of, because in _Imperium_,
the time-traveler is invisible, not apparently on fire.
Oh, well, I've never conflated two books. So far today, that is...
Mark L. Fergerson
Walter Bushell
David Johnston <da...@block.net> wrote:
> >- static time-space; nothing a traveler does changes anything, because
> >whatever will happen, already has. In this model, time-travelers can't
> >kill their early selves. This one is internally consistent
>
> And totally eliminates the illusion of free will.
Let say the illusion gets one more karate chop to the back of the neck.
--
A computer without Microsoft is like a chocolate cake without mustard.
Joseph Nebus
>On Sep 23, 9:40=A0pm, t...@loft.tnolan.com (Ted Nolan <tednolan>) wrote:
>>
>> In the Cryod books (and I highly recommend the first two: _Croyd_ & _Dr.
>> Orpheus_) going into the past is referred to as going "uptime" since you
>> are going against the flow of time.
>And so this boring thread spawns an interesting scientiphilological
>question: which way is "uptime" (and "downtime") in stf, generally
>speaking?
>Uptime =3D pastward:
>1. Ian Wallace, _Croyd_ etc.
>Uptime =3D futureward:
>1. Poul Anderson, _There Will Be Time_ etc.
>2. Crawford Kilian, _The Empire of Time_
>So far, it's 2 to 1 in favor of uptime =3D futurward & downtime =3D
>pastward. Any other examples? I couldn't find "uptime" or "downtime"
>in Silverberg's _Up the Line_, though I wouldn't bet my house they
>aren't there; if they *were* there, presumably "uptime" would mean
>"pastward", i.e. "up the line".
I don't remember if Asmiov used 'uptime' or 'upwhen' for _The
End Of Eternity_, but I'm fairly sure the up direction was towards the
future.
I wonder if there's any connection to a general belief in the
inevitability of progress. If you figure that, on average, things are
getting better as time goes on, and also associate up-ness with good
things, then it all fits into a conceptual whole of the far future
being very up-pish.
--
Joseph Nebus
------------------------------------------------------------------------------
David DeLaney
>Erik Max Francis <m...@alcyone.com> wrote:
>>It also would suggest Niven's law on time travel: Unrestricted time
>>travel that really can change the past, cause paradoxes, etc. suggests
>>an unstable state. It's not unreasonable to conclude that eventually
>>this will have to settle down to a stable state, and the only way that
>>can happen is if no time travel machine ever gets invented or, if
>>invented, used.
>
>Why would it settle down to a stable state, though?
And that's definitely NOT the only way it can happen. It's just a very EASY way.
Dave
--
\/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
David DeLaney
>> where changes somehow take this "metatime" to propagate. This is
>> awfully common in the more popularized science fiction such as _Back to
>> the Future_, though it probably makes the least sense.
>
>It makes perfect sense. Metatime is just time as measured by clocks
>residing outside of the television rather than inside.
>
>The only remaining question is how we can get access to clocks outside
>our TV so we can tell what's going on when we start traveling through time.
you are georges mordreaux
and i claim a layer of softly waving grass
Walter Bushell
<97e8a92e-81fa-43b6...@o21g2000vbl.googlegroups.com>,
Eg. Lessa brought the Oldtimers forward in time, because she already
had. Or at least they left the old time, arrival in the new time was not
known when they left.
Wayne Throop
:::: because whatever will happen, already has. In this model,
:::: time-travelers can't kill their early selves. This one is
:::: internally consistent
:: And totally eliminates the illusion of free will.
: Let say the illusion gets one more karate chop to the back of the neck.
Seems like it's the same karate chop it got from "if you're so smart and
have free will, why can't you decide both ways at the same time, huh?".
Walter Bushell
wrote:
> Now, one could suppose there's a bistable state. A loop that has one
> outcome (you get born, decide to kill your grandfather) alternating
> with another outcome (you don't get born, and so don't decide to kill
> your grandfather).
You find out your grandfather wasn't in fact your grandfather, perhaps
the butler did it or reality provides a substitute. Self healing
hypothesis -- any change results in a change that restores the status
quo.
David Johnston
wrote:
If I had time travel I could.
David Johnston
wrote:
>In article <12537...@sheol.org>, thr...@sheol.org (Wayne Throop)
>wrote:
>
>> Now, one could suppose there's a bistable state. A loop that has one
>> outcome (you get born, decide to kill your grandfather) alternating
>> with another outcome (you don't get born, and so don't decide to kill
>> your grandfather).
>
>You find out your grandfather wasn't in fact your grandfather, perhaps
>the butler did it or reality provides a substitute. Self healing
>hypothesis -- any change results in a change that restores the status
>quo.
The problem with that is that you don't have to to kill your
grandfather to set up a grandfather paradox. All you have to to do
send something back in time, and then when your past self catches up
with your present self, decide not to send it back to see what
happens. And make no mistake, someone would do that.
Patok
> In article <12537...@sheol.org>, thr...@sheol.org (Wayne Throop)
> wrote:
>
>> Now, one could suppose there's a bistable state. A loop that has one
>> outcome (you get born, decide to kill your grandfather) alternating
>> with another outcome (you don't get born, and so don't decide to kill
>> your grandfather).
>
> You find out your grandfather wasn't in fact your grandfather, perhaps
> the butler did it or reality provides a substitute. Self healing
> hypothesis -- any change results in a change that restores the status
> quo.
That self-healing thing is prominent in some time-travel novels,
and it always bothers me, unless the author rejects the butterfly effect
as well. It doesn't make sense that small changes in one's own time
amplify, while the same changes in another time get damped. Butterfly
effect for both is much more consistent - Bradbury's sound of thunder,
to name a good example, with butterflies. :)
--
You'd be crazy to e-mail me with the crazy. But leave the div alone.
Wayne Throop
: The problem with that is that you don't have to to kill your
: grandfather to set up a grandfather paradox. All you have to to do
: send something back in time, and then when your past self catches up
: with your present self, decide not to send it back to see what
: happens. And make no mistake, someone would do that.
Absent metatime, there would still be some object in two states.
Such macroscopic objects, from quantum mechanics, don't exist; they'll
collapse into one state or another.
So, somebody might plan to do that, but they'll only be able to succeed
if they're working with a particle, or possibly a bose-einstein condensate
(and that applies to the decision of what to do as well).
Your question of "why will they fail" is the same question of "why will
objects collapse into a single state, when from the viewpoint of quantum
mechanics objects can have a superposition of states". And your brain
leading up to the decision to send or not send *is* such a macroscopic
object. So, you will simply make a consistent decision, for the same
reason that you can't just decide to both go to work and stay home
at the same time. You might think "I'll make a different decision next
time around", but there's no next time around.
In some sense, this is the "obvious mechanism", because now that I browse
on wikipedia, I see that others have made the same suggestion. You may
think "oh, that's a lame mechanism", and you may be right, but that's not
the same thing as saying "nobody has a mechanism in mind, it's all just
wishful thinking".
Wayne Throop
:: and have free will, why can't you decide both ways at the same time,
:: huh?".
: David Johnston <da...@block.net>
: If I had time travel I could.
How does time travel help you do it?
Remember, the hypothesis is, no metatime, no multiverse.
You may say, "it gives me another chance to make the decision",
but I don't see how; leading up to the decision, you're always going
to have exactly the same information as you always have.
David Johnston
wrote:
>:: Seems like it's the same karate chop it got from "if you're so smart
The time traveller has more information. He knows how things turned
out.
David Johnston
wrote:
>: David Johnston <da...@block.net>
>: The problem with that is that you don't have to to kill your
>: grandfather to set up a grandfather paradox. All you have to to do
>: send something back in time, and then when your past self catches up
>: with your present self, decide not to send it back to see what
>: happens. And make no mistake, someone would do that.
>
>Absent metatime, there would still be some object in two states.
>Such macroscopic objects, from quantum mechanics, don't exist; they'll
>collapse into one state or another.
>
>So, somebody might plan to do that, but they'll only be able to succeed
>if they're working with a particle, or possibly a bose-einstein condensate
>(and that applies to the decision of what to do as well).
>
>Your question of "why will they fail" is the same question of "why will
>objects collapse into a single state, when from the viewpoint of quantum
>mechanics objects can have a superposition of states". And your brain
>leading up to the decision to send or not send *is* such a macroscopic
>object.
So even though you have every reason to want things to happen
differently, quantum physics will take your brain over and force you
not to do anything about it, turning you into a zombie-like sleep
walker?
David Johnston
wrote:
But there is no butterfly effect in that story. History is almost
exactly the same even though changes had hundreds of millions of years
to permutate.
Wayne Throop
:: will objects collapse into a single state, when from the viewpoint of
:: quantum mechanics objects can have a superposition of states". And
:: your brain leading up to the decision to send or not send *is* such a
:: macroscopic object.
: David Johnston <da...@block.net>
: So even though you have every reason to want things to happen
: differently, quantum physics will take your brain over and force you
: not to do anything about it, turning you into a zombie-like sleep
: walker?
Yes, exactly. The flesh will rot from your bones, and you'll shuffle
around saying "braaaaaaaaiiiins...". See for example the people in
"The Chronoliths", which seemed to me to use that model of timeloops.
Wayne Throop
:::: smart and have free will, why can't you decide both ways at the
:::: same time, huh?".
::: If I had time travel I could.
:: How does time travel help you do it? Remember, the hypothesis is, no
:: metatime, no multiverse. You may say, "it gives me another chance to
:: make the decision", but I don't see how; leading up to the decision,
:: you're always going to have exactly the same information as you
:: always have.
: David Johnston <da...@block.net>
: The time traveller has more information.
: He knows how things turned out.
Who else are you comparing to? There's only one person here;
the time traveler. How does "having more information" help you to
choose two things at once and end up in a superposition of states?
Default User
> In article <12537...@sheol.org>, thr...@sheol.org (Wayne Throop)
> wrote:
>
> > Now, one could suppose there's a bistable state. A loop that has
> > one outcome (you get born, decide to kill your grandfather)
> > alternating with another outcome (you don't get born, and so don't
> > decide to kill your grandfather).
>
> You find out your grandfather wasn't in fact your grandfather,
> perhaps the butler did it or reality provides a substitute. Self
> healing hypothesis -- any change results in a change that restores
> the status quo.
Your grandmother has just lost her fiance, and needs comforting . . .
Brian
--
Day 234 of the "no grouchy usenet posts" project
Default User
Here's another one, sort of related to the topic. Read in Analog, I
think, 10+ years back most likely.
Anyway, the technology has been devised to "roll back" time to an
earlier point. For some reason, the person that does the rollback
remembers what happened in the "time that didn't happen", but no one
else does. The technology becomes freely available, to the point where
there are machines to initiate rollbacks all over the city. Spill soup
on yourself at lunch? Roll back 10 minutes. Mad at the boss? Bring in
baseball bat and bash him up, then roll back to the start of the day.
There wasn't much else to the story, other than some people at a
restaurant who spill wine or something and decide NOT to roll back.
David Johnston
wrote:
>:::: Seems like it's the same karate chop it got from "if you're so
>:::: smart and have free will, why can't you decide both ways at the
>:::: same time, huh?".
>
>::: If I had time travel I could.
>
>:: How does time travel help you do it? Remember, the hypothesis is, no
>:: metatime, no multiverse. You may say, "it gives me another chance to
>:: make the decision", but I don't see how; leading up to the decision,
>:: you're always going to have exactly the same information as you
>:: always have.
>
>: David Johnston <da...@block.net>
>: The time traveller has more information.
>: He knows how things turned out.
>
>Who else are you comparing to?
Him before he made the choice.
There's only one person here;
>the time traveler. How does "having more information" help you to
>choose two things at once and end up in a superposition of states?
I make a decision. Oh noes, decision was bad! But hey! I have a
time machine! Sherman set the Wayback Machine! I go back. I tell
myself what was going to happen. Or maybe I just take the decision
out of my previous self's hands by switching orders at the restaurant
so he'll eat the lobster instead of the toxic cod.
Wayne Throop
: I make a decision. Oh noes, decision was bad! But hey! I have a
: time machine! Sherman set the Wayback Machine! I go back. I tell
: myself what was going to happen.
You seem to think somebody appears and provides you information you
didn't have before. Which contradicts the assumption of no metatime.
There IS no "you about to make a bad decision with no advice" to compare
to "you about to make a decision, having advice in hand". There's only
one person, you, and (in this scenario), you have the advice of your
future self. That's the whole point of there not being metatime.
In short, you're just saying "but there IS SO metatime", which
is... well... wishful thinking, with (dare I say) no mechanism for it.
David Johnston
wrote:
>: David Johnston <da...@block.net>
>: I make a decision. Oh noes, decision was bad! But hey! I have a
>: time machine! Sherman set the Wayback Machine! I go back. I tell
>: myself what was going to happen.
>
>You seem to think somebody appears and provides you information you
>didn't have before. Which contradicts the assumption of no metatime.
If it does, then I don't understand that assumption and how it works
in concert with actually having time travel at all.
Erik Max Francis
If you're talking about the reverse grandfather paradox (though it
really works either way) here, the you that was in the past is you in
your own future. You have no foreknowledge of what you did in the past,
because you haven't done it yet. There's only one time when you find
yourself with the choice to go back in time or not, and it hasn't
happened yet. When it does happen, you'll have no more information
about what you will have done in the past then you do currently,
because, as I said, you haven't done it yet.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
War is cruelty, and you cannot refine it.
-- Karl Shapiro
William George Ferguson
talk-o...@moderators.isc.or�g <rja.ca...@excite.com> wrote:
>On Sep 23, 8:59�am, William George Ferguson <wmgfr...@newsguy.com>
>wrote:
>> Normally jumps on Pern, from any point to any point on the two
>> main continents, isn't far enough to cause an appreciable difference in the
>> length of the journey (Nobody seems to jump to the third continent, so we
>> don't have a marker for that). �When F'Nor jumped to the Red Star it took
>> him noticeably longer (when Jaxom et alia jumped to the Dawn Sisters, in
>> geostationary (pernostationary?) orbit, there wasn't an appreciable time
>> lag, and that was likely further than to the Far Western Continent). �When
>> jumping through time, the lag becomes noticeable at about 10 years.
>
>
>Can we try to put a figure on the Dawn Sisters distance?
>Geostationary is about 36,000 km / 22,000 miles above sea level
>according to Wikipedia. Earth's radius is about 6,370 km, so it
>counts significantly whether you measure distance from centre of mass
>or from surface; I presume 36,000 km is the length of elevator cable
>required, not counting the counterweight. (For a beanstalk, which
>Pern doesn't have.) Pern is less massive, I think, but somehow has
>enough atmosphere for flying dragons, or do we have to assume that
>they're levitating by telepathy, and the wings are... to bang together
>during mating season?
On the dragons, we don't have to assume. In a later book (almost certainly
written by Todd McCaffrey even though it still had Anne's name on the
cover), F'lessan (F'lar and Lessa's only child) is crippled as is his
dragon. It's established then that the dragons negate some of their weight
by telekineses. Golanth was able to lift F'Lessan out of reach of an
attack by uplifted felines, although he could not then fly because of the
injuries previously inflicted on his wing by the cats.
>If Pern is smaller then intercontinental distances are obviously
>shorter...
I've always figured that Pern is likely slightly larger than Earth, but has
the same or lower gravity due to it having lower amounts of the heavier
elements (that it is metal poor is a major plot point, and any planet as
tectonically active as Pern that is metal poor can't have as much of the
heavier elements in it even at the core).
It does have enough copper that it is an essential part of the biochemistry
of the pernese native species, and is artificially introduced into the
imported Earth stock (including humans).
For the Dawn Sisters, if Pern is lighter, they may be slightly higher, or
lower, but look at Earth. The furthest any two points on the surface are
from each other if roughly 12,000 miles, which is about half the distance
from the surfact to geostationary orbit. It would be hard to design a
system where half the circumfrence of Pern (or any planet except maybe
Mesklin) isn't a good deal less than the distance from the surface to
geosynchronous orbit.
--
I must not fear. Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear. I will permit it to pass over me and through me.
And when it has gone past I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain.
(Bene Gesserit)
Wayne Throop
:: didn't have before. Which contradicts the assumption of no metatime.
: David Johnston <da...@block.net>
: If it does, then I don't understand that assumption and how it works
: in concert with actually having time travel at all.
Right. So (near as I can tell) you can't imagine time travel without
metatime in some form or another. But in reality, metatime is not
necessary at all. Certainly nothing in relativistic notions involving
closed timelike curves requires it. As it was in the beginning, is now,
and ever shall be, loop without end. Amen. Adding loops to spacetime
with no metatime changes nothing... well, other than solidifying that
chunk of spacetime as permanently collapsed, in the copenhagen sense,
I supopse, if one waves one's hands briskly enough.
Mind you, *none* of this means I find the model plausible or satisfying.
Just that it isn't mere wishful thinking with no conceived mechanism,
or at least, not quite.
Again, I recommend "The Chronoliths" for musings and meditations on how
such an artifact (ie, information from the future, under the no-metatime
assumption) affects decisionmaking, and ends up with people doing what
they swore they had no plans to do at all. Braaaaiiiins. "Recommend"
in the sense of an interesting working-through of concept; it may or may
not be enjoyable, in that a) it may not be your cuppa, and b) I found
it intensely depressing mood-wise (much like Spin, only perhaps worse).
But I'm still "glad" in some sense that I read it.
Erik Max Francis
> On Wed, 23 Sep 2009 14:14:26 -0700, Erik Max Francis <m...@alcyone.com>
> wrote:
>
>>> "Well, obviously that's not true," explains the time traveler.
>>> "Live with it. Hey, are you hungry? I could really go for some
>>> Chinese food."
>> Well, the total lack of logical consistency is arguably a pretty serious
>> problem. In terms of suspension of disbelief, perhaps the issue won't
>> present itself in an individual story. But if you want to take such
>> things seriously, you'll end up exploring the boundary conditions and
>> weird edge cases inevitable, even in the fictional world itself.
>
> The trouble is, we assume that everything has to have a cause - but we
> have no way of testing this assumption. It is a useful assumption to
> make, as long as we stay away from theology.
Well, it's a little more useful than that. Science doesn't work without
it, so it's ingrained into fundamental scientific philosophy.
Besides, if you want to really drill deep into the idea, time travel
doesn't eliminates strict timelike causality, but it introduces a new
type of meta-causality, taking into account closed timelike loops.
--
Erik Max Francis && m...@alcyone.com && http://www.alcyone.com/max/
San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
There is no evil in the atom; only in men's souls.
-- Adlai Stevenson, 1952
Erik Max Francis
> On Wed, 23 Sep 2009 17:09:18 -0700, Erik Max Francis <m...@alcyone.com>
> wrote:
>
>> David Johnston wrote:
>>> wrote:
>>>
>>>> What models of time travel do we see in literature? I can think of the
>>>> following:
>>>>
>>>> whatever will happen, already has. In this model, time-travelers can't
>>>> kill their early selves. This one is internally consistent
>>> And totally eliminates the illusion of free will.
>> will, a subject which often has seemed like philosophical mental
>> masturbation to me). What it does mean is that if you deliberately try
>> to go back in time and screw with things in sufficiently naughty ways,
>> something will stop you.
>
> To which the question is always "what"?
If the conjecture is true, then it's more along the lines of a physics
principle, rather than some simple rule.
For instance, (local) conservation of energy is pervasive in physics.
But to ask, "So, okay, how does conservation of energy get enforced?"
doesn't have a simple answer, because the exact mechanism is different
in different circumstances. The same could be true for the explanation
of a conjecture (which is true).
aaron
"Lawrence Watt-Evans" <l...@sff.net> wrote in message
news:2avlb5h4npgc44ipt...@news.eternal-september.org...
> On Wed, 23 Sep 2009 17:27:59 -0700, Erik Max Francis <m...@alcyone.com>
> wrote:
>
>>It also would suggest Niven's law on time travel: Unrestricted time
>>travel that really can change the past, cause paradoxes, etc. suggests
>>an unstable state. It's not unreasonable to conclude that eventually
>>this will have to settle down to a stable state, and the only way that
>>can happen is if no time travel machine ever gets invented or, if
>>invented, used.
>
> Why would it settle down to a stable state, though?
The anthropic principle? That we do not perceive a changing, changed,
changeable past might imply that is so because of the potential outcomes
that is what occurred?
Wayne Throop
Because there's no metatime. Absent metatime, a timeloop will act as
if it's had an infinite amount of time to find and settle into a stable
state... and once it does, well, there you are. Except of course,
absent metatime, there's no "once it does"... it just does. Or rather,
it just *is*. There's no way to observe anything that *isn't* stable.
If it weren't stable, it would change, and there's no metatime for it
to change IN.
David Johnston
wrote:
>David Johnston wrote:
>> On Wed, 23 Sep 2009 17:09:18 -0700, Erik Max Francis <m...@alcyone.com>
>> wrote:
>>
>>> David Johnston wrote:
>>>> On Wed, 23 Sep 2009 13:44:13 -0400, Patok <crazy.d...@gmail.com>
>>>> wrote:
>>>>
>>>>> What models of time travel do we see in literature? I can think of the
>>>>> following:
>>>>>
>>>>> - static time-space; nothing a traveler does changes anything, because
>>>>> whatever will happen, already has. In this model, time-travelers can't
>>>>> kill their early selves. This one is internally consistent
>>>> And totally eliminates the illusion of free will.
>>> Perhaps, perhaps not (if indeed there really is such a thing as free
>>> will, a subject which often has seemed like philosophical mental
>>> masturbation to me). What it does mean is that if you deliberately try
>>> to go back in time and screw with things in sufficiently naughty ways,
>>> something will stop you.
>>
>> To which the question is always "what"?
>
>If the conjecture is true, then it's more along the lines of a physics
>principle, rather than some simple rule.
>
>For instance, (local) conservation of energy is pervasive in physics.
>But to ask, "So, okay, how does conservation of energy get enforced?"
That's a real question when someone insists that conservation of
energy still applies when you have a cycling teleportal (which is to
say, a situation where a teleportal at the bottom of a shaft teleports
everyone who hits it 50 feet up. How does conservation of energy get
enforced? Either such a situation is impossible (because you can't
actually teleport 50 feet up) or conservation of energy is being
violated, or there's a power source being drawn on that inserts that
much energy into the system to "enforce" the law of conservation of
energy.
Howard Brazee
wrote:
>The problem with that is that you don't have to to kill your
>grandfather to set up a grandfather paradox. All you have to to do
>send something back in time, and then when your past self catches up
>with your present self, decide not to send it back to see what
>happens. And make no mistake, someone would do that.
Heck, if your dad came a second later, or if your mom jumped out of
bed with a bit more force, it might have been a different sperm
winning the egg.
--
"In no part of the constitution is more wisdom to be found,
than in the clause which confides the question of war or peace
to the legislature, and not to the executive department."
- James Madison
Wayne Throop
: That's a real question when someone insists that conservation of
: energy still applies when you have a cycling teleportal (which is to
: say, a situation where a teleportal at the bottom of a shaft teleports
: everyone who hits it 50 feet up. How does conservation of energy get
: enforced? Either such a situation is impossible (because you can't
: actually teleport 50 feet up) or conservation of energy is being
: violated, or there's a power source being drawn on that inserts that
: much energy into the system to "enforce" the law of conservation of
: energy.
That's part of Eric's point as I understand it. That is, the general
principle just *is*, the enforcement is a matter of after-the-fact accounting.
If any macroscopic nonlocal process is composed of small local processes that
all conserve energy, then there's no "enforcement" going on, and it's
practically a category error to ask what enforces it. The real question
is, what small local processes are going on, and how to they combine;
the "enforcement" is simply that adding up lots of zeroes isn't going to
get you anything but zero.
But how about this analogy. What enforces that light moves in straight lines?
(Or, on geodesics in a vacuum, but to a good approximation, straight lines.)
Why doesn't it just wander around wherever it wants? And what enforces
equal angles when it reflects, etc, etc, etc. You can come up with lots
of interesting "mechanicms" for it in terms of summing quantum mechanical
probabilities across all possible paths (including bent ones), and find
out that the bent ones all cancel.
In this case, simiar things along a time loop. You can come up with
all sorts of superpositions of states, and what happens if choices are
made every which way at every turn... but when you combine them, all
the nearby choices to the actual one will cancel out.
Shrug. I really don't see why this is such a huge hairy deal.
David DeLaney
>Eg. Lessa brought the Oldtimers forward in time, because she already
>had. Or at least they left the old time, arrival in the new time was not
>known when they left.
Meanwhile (FSVO 'meanwhile'), Cabell had the Old Time merrily going along at
the castle at the High Place, for a while...
Dave "not to mention time travel through a deftly-inserted decimal point"
DeLaney
--
\/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower
It's not the clock that slows the hour The definition's plain for anyone to see
Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK>
http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
Patok
> Patok <crazy.d...@gmail.com> wrote:
>
>> That self-healing thing is prominent in some time-travel novels,
>> and it always bothers me, unless the author rejects the butterfly effect
>> as well. It doesn't make sense that small changes in one's own time
>> amplify, while the same changes in another time get damped. Butterfly
>> effect for both is much more consistent - Bradbury's sound of thunder,
>> to name a good example, with butterflies. :)
>
> But there is no butterfly effect in that story. History is almost
> exactly the same even though changes had hundreds of millions of years
> to permutate.
Let's agree to disagree here. First, the grain-of-salt explanation:
there is a butterfly, and it has an effect - therefore, a butterfly
effect. The serious one: who says that the effect has to be vast? It is
enough that the result of the initial conditions change is significantly
amplified. The trampling of a butterfly results in a different spelling
and changed political conditions; results clearly broader in scope and
effect. How it happened that they were precisely of this nature, is a
completely different question. I'd think it much more likely for the
returning time travelers to be met by sentient lizards, for instance.
But it is a butterfly effect in my book.
David Johnston
wrote:
>: David Johnston <da...@block.net>
>: That's a real question when someone insists that conservation of
>: energy still applies when you have a cycling teleportal (which is to
>: say, a situation where a teleportal at the bottom of a shaft teleports
>: everyone who hits it 50 feet up. How does conservation of energy get
>: enforced? Either such a situation is impossible (because you can't
>: actually teleport 50 feet up) or conservation of energy is being
>: violated, or there's a power source being drawn on that inserts that
>: much energy into the system to "enforce" the law of conservation of
>: energy.
>
>That's part of Eric's point as I understand it. That is, the general
>principle just *is*, the enforcement is a matter of after-the-fact accounting.
>If any macroscopic nonlocal process is composed of small local processes that
>all conserve energy, then there's no "enforcement" going on, and it's
>practically a category error to ask what enforces it. The real question
>is, what small local processes are going on, and how to they combine;
>the "enforcement" is simply that adding up lots of zeroes isn't going to
>get you anything but zero.
>
>But how about this analogy. What enforces that light moves in straight lines?
>(Or, on geodesics in a vacuum, but to a good approximation, straight lines.)
Nothing needs to because light isn't sentient and self-propelled.
People with time machines are.
Wayne Throop
: Nothing needs to because light isn't sentient and self-propelled.
So... dualism? If so, I find it unconvincing.
George W Harris
wrote:
>>That's part of Eric's point as I understand it. That is, the general
>>principle just *is*, the enforcement is a matter of after-the-fact accounting.
>>If any macroscopic nonlocal process is composed of small local processes that
>>all conserve energy, then there's no "enforcement" going on, and it's
>>practically a category error to ask what enforces it. The real question
>>is, what small local processes are going on, and how to they combine;
>>the "enforcement" is simply that adding up lots of zeroes isn't going to
>>get you anything but zero.
>>
>>But how about this analogy. What enforces that light moves in straight lines?
>>(Or, on geodesics in a vacuum, but to a good approximation, straight lines.)
>
>Nothing needs to because light isn't sentient and self-propelled.
>People with time machines are.
Yet people and time machines are also accumulations
of small local processes. Sentience is an artifact of our
means of observing the universe (just like the concept of
'now'), and the universe doesn't care about it.
So, nothing needs to enforce it with people either.
--
Doesn't the fact that there are *exactly* 50 states seem a little suspicious?
George W. Harris For actual email address, replace each 'u' with an 'i'
Wayne Throop
: George W Harris <gha...@mundsprung.com>
: Yet people and time machines are also accumulations of small local
: processes.
Raising the question of why sentient critters conserve energy.
But of course, why a teleporter did, was supposed to be mysterious,
too, upthread.
David Johnston
wrote:
>: David Johnston <da...@block.net>
>: Nothing needs to because light isn't sentient and self-propelled.
>: People with time machines are.
>
>So... dualism?
Not even a little bit. Light moves in straight lines because it has
no means to change course. That has nothing to do with dualism.