YASID for time paradox scenario (was: Time Machines, FTL, and P=NP)
Wayne Throop
::: unlikely ways, it looks to me not too hard to set up a situation
::: where /no/ possible outcome is consistent. For my simple example,
::: just put the received signal through a NOT gate before sending it
::: back in time. What happens in that case? Hard reboot on the
::: universe?
:: Mechanical failure of the time machine, or some other break in the chain.
: But, under the assumption that a zero or a one completely
: characterizes the message from the future, there are only two links in
: the chain. -- What happens when I receive a zero? I send a one. --
: What happens when I receive a one? I send a zero. There is no "What
: happens the 8,471,843,189,287,125th time I send a one?" If it didn't
: crash on the first loop, it didn't crash.
If it's a loop (ie, if there could be a "first loop"),
it has an Nth iteration. If not, then "crash on the first loop"
isn't a good description.
Is there really a difference (besides angels-on-heads-of-pins type of
difference) between "it never does that" vs "it loops, erasing timelines,
until it doesn't do that"?
: And, by assumption, the machine was built to be extremely reliable. I
: don't see how the machine could be expected to crash, except by the
: sort of wackiness that the assumption I started with was supposed to
: banish.
Hm. I've mentioned Thiotimoline and Thrice Upon a Time as examples, and
possibly Niven's story about the Tipler cylinder might fit. But it seems
to me there was a YASID where somebody comes up with a theory of time
travel, and finds it should be really qutie easy to come up with a robust
mechanism to accomplish it (or to9 do some other paradoxical thing).
But every attempt to use the machine has a freak, seeminly urelated,
accident occur to prevent it. Power falure just as you throw the switch,
very reliable component fails with a 1-in-a-zillion manufacturing defect,
bolt of lightning out of a clear blue sky, whatever. It's eventually
realized that the universe simply goes round and round the paradox loop
until some happenstance jars it out of its rut (or, it's realized that
alternate timelines where the machine works are all edited out). This is
pretty much the Niven point from "Theory and Practice of Time Travel",
where in any universe where a time machine is possible, it will never
be invented, except more like s/possible/invented/ and
s/invented/successfully implemented/.
ANYhow. Just how many SF stories with this particular trope are there,
and does anybody remember oen that maches the "minor freak accidents
keep happening, and eventually it's realized that they are inadvertently
editing the universe" scenario?
Wayne Throop thr...@sheol.org http://sheol.org/throopw
P. Taine
"Brooklyn Project", William Tenn, 1948. In lots of collections.
P. Taine
Well (realized after "send"), the point here is that they DON'T Realize it.
Dan Goodman
> On Sat, 23 Feb 2008 01:29:50 GMT, thr...@sheol.org (Wayne Throop)
> wrote:
>
> > ::: But then, without the wackiness to force consistency in highly
> > ::: unlikely ways, it looks to me not too hard to set up a situation
> > ::: where no possible outcome is consistent. For my simple example,
If I understand the question correctly -- no.
In "Brooklyn Project," there's nothing to suggest any changes from time
travel.
--
Dan Goodman
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Wayne Throop
: In "Brooklyn Project," there's nothing to suggest any changes from
: time travel.
Hm. Well, "other timelines implode" seems a related concept.
Isn't that more or less what's happening?
Joseph Nebus
>ANYhow. Just how many SF stories with this particular trope are there,
>and does anybody remember oen that maches the "minor freak accidents
>keep happening, and eventually it's realized that they are inadvertently
>editing the universe" scenario?
I believe Fritz Leiber had one in his Change War universe with
a name like ``Try And Change The Past'', in which various efforts to
get a guy to *not* be shot are routinely foiled by events of ever more
Nicollesque improbability. I believe this was meant as one of those odd
little frustrating things about a time war, that now and then you just
hit things that won't go differently.
--
Joseph Nebus
------------------------------------------------------------------------------
Dan Goodman
> thr...@sheol.org (Wayne Throop) writes:
>
> > ANYhow. Just how many SF stories with this particular trope are
> > there, and does anybody remember oen that maches the "minor freak
> > accidents keep happening, and eventually it's realized that they
> > are inadvertently editing the universe" scenario?
>
> I believe Fritz Leiber had one in his Change War universe with
> a name like ``Try And Change The Past'', in which various efforts to
> get a guy to not be shot are routinely foiled by events of ever more
> Nicollesque improbability. I believe this was meant as one of those
> odd little frustrating things about a time war, that now and then you
> just hit things that won't go differently.
It's indeed "Try and Change the Past."
David DeLaney
>thr...@sheol.org (Wayne Throop) writes:
>>ANYhow. Just how many SF stories with this particular trope are there,
>>and does anybody remember oen that maches the "minor freak accidents
>>keep happening, and eventually it's realized that they are inadvertently
>>editing the universe" scenario?
>
> I believe Fritz Leiber had one in his Change War universe with
>a name like ``Try And Change The Past'', in which various efforts to
>get a guy to *not* be shot are routinely foiled by events of ever more
>Nicollesque improbability. I believe this was meant as one of those odd
>little frustrating things about a time war, that now and then you just
>hit things that won't go differently.
A related theme is partly spelled out in Moran's timewar portions of his
Continuing Time series - the two time fighters, the Name Player and Camber
of Cul^W^WTremodian, have to be careful about where and when they go so as
not to erase the gains they've already made, and have constraints on them
as to places they absolutely _can't_ go (possibly 'any more'). But they're
still making adjustments where and when they can to tip the balance their
way, though it seems the adjustments are ones that must have already been
made to get the history to work right anyway...
Dave
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James Nicoll
Joseph Nebus <nebusj-@-rpi-.edu> wrote:
>thr...@sheol.org (Wayne Throop) writes:
>
>>ANYhow. Just how many SF stories with this particular trope are there,
>>and does anybody remember oen that maches the "minor freak accidents
>>keep happening, and eventually it's realized that they are inadvertently
>>editing the universe" scenario?
>
> I believe Fritz Leiber had one in his Change War universe with
>a name like ``Try And Change The Past'', in which various efforts to
>get a guy to *not* be shot are routinely foiled by events of ever more
>Nicollesque improbability.
I've never been hit by a meteor. The closest one ever got was miles
away from me.
--
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> ::: But then, without the wackiness to force consistency in highly
> ::: unlikely ways, it looks to me not too hard to set up a situation
> ::: where /no/ possible outcome is consistent. For my simple example,
> ::: just put the received signal through a NOT gate before sending it
> ::: back in time. What happens in that case? Hard reboot on the
> ::: universe?
>
> :: Mechanical failure of the time machine, or some other break in the chain.
>
> : But, under the assumption that a zero or a one completely
> : characterizes the message from the future, there are only two links in
> : the chain. -- What happens when I receive a zero? I send a one. --
> : What happens when I receive a one? I send a zero. There is no "What
> : happens the 8,471,843,189,287,125th time I send a one?" If it didn't
> : crash on the first loop, it didn't crash.
>
> If it's a loop (ie, if there could be a "first loop"),
> it has an Nth iteration. If not, then "crash on the first loop"
> isn't a good description.
>
> Is there really a difference (besides angels-on-heads-of-pins type of
> difference) between "it never does that" vs "it loops, erasing timelines,
> until it doesn't do that"?
>
> : And, by assumption, the machine was built to be extremely reliable. I
> : don't see how the machine could be expected to crash, except by the
> : sort of wackiness that the assumption I started with was supposed to
> : banish.
Perhaps the idea of a loop gives you a bad picture. What happens in
the future, after the computer sends back the information? Does it
vanish instantaneously? I like the idea of playing with the 'Life
Block Universe' (to distinguish it from Einstein's Block Universe.)
Imagine the game of Life is set up so that instead of the changes in
state being applied repeatedly to the same cells, the results are
transfered to an adjacent sheet of cells. So then a computation is
performed once in each sheet, and the results propagate 'forward' into
the mysterious third dimension, leaving behind a static trace. I
think this is close to the mental picture a lot of people have for the
situation in our world.
What happens when connections are set up between layers that are far
apart? You get a 'looping' between those two layers, but it doesn't
affect what has already been propagated forward. In this model,
sending a 'one' back to a previous sheet results in the recipient - or
the propagated copy of the recipient, if you prefer - sending a
'zero' back. And this will happen indefinitely unless something
happens to break the connection. I don't see how there are any
paradoxes in this scenario, or indeed, how any paradoxes can arise at
all. There will be a wavefront where the person sending the zero
back will say 'Ha! Nothing happened! The universe is protected from
time paradoxes!", and who will continue living an ordinary life. This
will be followed be a wavefront in which the person sends back a one
and echoes the same sentiments. This leads one to ask how the
different sheets can be connected, perhaps a more interesting
question. Can connections be arbitrarily established between any two
sheets? If a connection is established between sheet n and n-k, does
it follow automatically that there will be a connection between sheets
n+1 and n-k+1?
David DeLaney
>Joseph Nebus <nebusj-@-rpi-.edu> wrote:
>> I believe Fritz Leiber had one in his Change War universe with
>>a name like ``Try And Change The Past'', in which various efforts to
>>get a guy to *not* be shot are routinely foiled by events of ever more
>>Nicollesque improbability.
>
> I've never been hit by a meteor.
Yet.
>The closest one ever got was miles away from me.
At least, as far as you've perceived.
Dave "raindrops and microdust" DeLaney
Quadibloc
> It's indeed "Try and Change the Past."
Of course (referring to another story), after 9/11, I've started
rooting for the spaghetti sauce.
John Savard
John M. Gamble
>: "Dan Goodman" <dsg...@iphouse.com>
>: In "Brooklyn Project," there's nothing to suggest any changes from
>: time travel.
>
>Hm. Well, "other timelines implode" seems a related concept.
>Isn't that more or less what's happening?
>
>
Nope. You may have this confused with a different story.
"The question before us: should we *shilk* or shouldn't we *shilk*?"
--
-john
February 28 1997: Last day libraries could order catalogue cards
from the Library of Congress.
John M. Gamble
Simon Slavin
<fppd7l$5t2$1...@reader2.panix.com>:
> Joseph Nebus <nebusj-@-rpi-.edu> wrote:
> >I believe Fritz Leiber had one in his Change War universe with
> >a name like ``Try And Change The Past'', in which various efforts to
> >get a guy to *not* be shot are routinely foiled by events of ever more
> >Nicollesque improbability.
>
> I've never been hit by a meteor. The closest one ever got was miles
> away from me.
Wrong. You were hit by a meteor and rescued using 24th Century medical
technology which was also used to wipe your memory of the incident.
It's science fiction. The possibilities are bounded only by the writer's
self-respect.
Simon.
--
http://www.hearsay.demon.co.uk