NationStates Jolt Archive

I was reading a bit on something by Stephen Hawking (not sure which one), and he talked about how Time Travel to the past would be logically impossible. Here's what he explained:

By travelling to the past, you have effectively curbed the need of travelling to the past, henceforth since you have created the machine, you will have no need to have created the machine, and henceforth you will not have the time machine, meaning you never went back in the first place, meaning you would be stuck at the time you originally were at.

To clear it up a bit, I'm putting an example.

My friend says he wants to take a couple working nuclear devices and go to the times of the Roman Empire, and declare himself God. He says that he will nuke Rome in an effort to make them see him as God. Now, if he used a Time Machine to do this, then he would have gone back in time and done it, henceforth it is changed, therefore he has finished the purpose of what he built the time Machine for, therefore it would register as him not building a time machine at all, henceforth he will not have a time machine, and then it will been as he hasn't gone back in time.

Another interesting thing related but different is the idea of time in different intervals. For example, if a ball is thrown into a void that would make it go forwards in time, then the time required for that ball to travel in the void would make it kinda redundant, meaning the time used by the void is from a different reality.

What are your thoughts on Time Travel? I would appreciate and fair, serious dicussion, though I know this is NS General. :rolleyes:

I'm under the impression that it's possible there are infinite dimensions of possibility (I use the word "dimensions" to mean separate universes of existence) therefore the whole "Timetravel would counteract itself" would be moot if going back in time created or affected a different dimension.

Owwwwww!

It hurts my head! :headbang:

Those are my basic thoughts.

But as for what I truly think of it. I think time travel could potentially create a metaphysical cataclysm. A property of matter is that it cannot be created and it cannot be destroyed. Lets say I travel back in time. Since nothing was there before I "arrived", I am, in effect, creating matter. That's not supposed to happen! I think it would cause some kind of imbalance, kinda like dividing by zero.

In the situation described, the need to build the time machine is still there. As the pre-time-travel friend has not yet declared himself God over Rome, he will still need to go back in time to declare himself such. However, now he has the knowledge that he will and did succeed.

The question is not whether the *need* for the time machine still exists. It is the question as to whether he sufficiently altered history in such a way that he never would have been born in the first place. If he doesn't exist, then he can't create the time machine, which means he can't alter history, so he will exist anyway... then he creates the time machine...

But surely, if you go back to 40-odd BC, nuke Rome and declare yourself a God...Whilst your urge to create a time machine (Specifically for that purpose) would undeniably be removed, thus stopping you from ever going back to that time (Disregarding other times you may or may not visit), would that create an alternate you? Obviously the fact that Rome had been nuked by you at that time would be true, because it would have to be, but would not that fact that you were also lived a normal day-to-day life in the year 2006, unconnected to (Or otherwise) any time machines, ALSO be true at the same time?

My future self came back in time to warn me to stay away from Time Travel.

My future self came back in time to warn me to stay away from Time Travel.

Oh God...a paradox...That'll mean that at sometime in the future you will be forced to ignore your alternate future self's warning and go back in time to warn your past self to stay away from time travel.

And don't EVER think of letting the cycle die! We have no idea what that'll do to the space-time continuum!

we can know that time travel to the past will never exist, because we'd know already, as we'd be visited by people from the future.

It's the old paradox of killing you father before you were conceived. One theory says the fact that you are alive means that even if you went back in time specifically to kill your father before you were conceived, you won't succeed. Another theory (impossible to test, it seems to me) is that you split off another dimension when you pull the trigger. This is generally the point at which I give up trying to understand it.

In the situation described, the need to build the time machine is still there. As the pre-time-travel friend has not yet declared himself God over Rome, he will still need to go back in time to declare himself such. However, now he has the knowledge that he will and did succeed.

The question is not whether the *need* for the time machine still exists. It is the question as to whether he sufficiently altered history in such a way that he never would have been born in the first place. If he doesn't exist, then he can't create the time machine, which means he can't alter history, so he will exist anyway... then he creates the time machine...
The reason that the need for the time machine is gone is because the friend would have grown up in a world where he was the conqueror of Rome. The problem with the scenario is that in the second "time-line" the friend might have a different need that stimulates the desire for a time machine. It needn't be *that* need.

It's kind of like "Two Minutes Mysteries".

we can know that time travel to the past will never exist, because we'd know already, as we'd be visited by people from the future.

Are you sure? In an attempt not to alter the timeline, time-travelers might be going about things very secretively.

we can know that time travel to the past will never exist, because we'd know already, as we'd be visited by people from the future.


How do you know we haven't been?

It's like that 'Don't listen to me' paradox.

I suscribe to this theory:
time travel is only possible in one direction: forward. We are constantly turning future into present.
However, if time travel was possible, then events would change. for example, if we prevented Hiroshima, that could cause a nuclear war since no one would know about the effects of intense radiation. If someone killed Bush a few months earlier, then Dick Cheney would be in charge and the assassin would have been ripped apart by angry liberals because Dick "quick-shot" Cheney is president. If someone went back in time and prevented Hitler from attacking London, Britian would have fallen since it would have been completely defenseless because of the RAF bombing campaign. That and the infinite-you complexity.

The infinite-you complexity states that if you went back in time a certain amount of time, you would have caused an infinite amount of perfect clones of you to appear, since you would technicly have went back in time an infinite amount of times. If you affect the past, like kill the other you before he or she could go back in time, you would have destroyed time itself since you created an impossibility since you killed yourself both directly and indirectly, thereby making your presence there a happened impossibility. Such an event could permanantly crippled time.

:headbang: my head hurts now

its allot like hitting yourself in the balls with a hammer it may in a way seem fun but once you've done it you won't ever do it again

I vaguely remember a show (possibly Twilight Zone) where a woman went back thru time to kill Hitler as a baby. She thought she succeeded. But after the death of the baby, the couple adopted another baby. The adopted kid's first name was Adolf.

its allot like hitting yourself in the balls with a hammer it may in a way seem fun but once you've done it you won't ever do it again

... :eek:

My understanding of backwards time travel is that while there, you can only cause history to happen; not change it. Otherwise, what you'd be travelling to would not be the past, but rather something else.

My understanding of backwards time travel is that while there, you can only cause history to happen; not change it. Otherwise, what you'd be travelling to would not be the past, but rather something else.

Like the movie Timeline?

we can know that time travel to the past will never exist, because we'd know already, as we'd be visited by people from the future.
Prime Directive becomes Prime Temporal Directive.

Also, a great many people here are already subject to historical tampering/revision by people who want records to say what they want instead of what has actually transpired in this timeline.
I don't need to belabour that.

I vaguely remember a show (possibly Twilight Zone) where a woman went back thru time to kill Hitler as a baby. She thought she succeeded. But after the death of the baby, the couple adopted another baby. The adopted kid's first name was Adolf.
Katherine Heigl! WooT!!!!! *slobbers*

Like the movie Timeline?
I don't know; never saw it. Did they go back in time and only cause history to happen rather than actually changing anything?

My future self came back in time to warn me to stay away from Time Travel.
Just hoping you don't purchase that sports almanac.

A couple of things.
A Brief History of Time talks about it not being possible, and
The Universe In A Nutshell talks about it being possible.

All the "paradox"ical loops aside, what needs to be addressed here is the issue of choice, and the probability/information content that choice possesses to steer a timeline in the NOW, and at ANY point where there is a suspension of probability.
Upon the idea that a being could traverse time in a fashion different than the one we apparently experience now, there the very act of time travel itself is along the timeline of the being(s) choosing to do so. They will still have biological processes that shall result in cell death et cetera, due the causal nature of existing along these intersecting planes/dimensions.
Further, someone needs to bring up the issue of geosynchronous discrepancy and situations of mass-oriented dilation to qualify variances in what is apparently erroneously assumed to be constant.

I was reading a bit on something by Stephen Hawking (not sure which one), and he talked about how Time Travel to the past would be logically impossible. Here's what he explained:

By travelling to the past, you have effectively curbed the need of travelling to the past, henceforth since you have created the machine, you will have no need to have created the machine, and henceforth you will not have the time machine, meaning you never went back in the first place, meaning you would be stuck at the time you originally were at.

To clear it up a bit, I'm putting an example.

My friend says he wants to take a couple working nuclear devices and go to the times of the Roman Empire, and declare himself God. He says that he will nuke Rome in an effort to make them see him as God. Now, if he used a Time Machine to do this, then he would have gone back in time and done it, henceforth it is changed, therefore he has finished the purpose of what he built the time Machine for, therefore it would register as him not building a time machine at all, henceforth he will not have a time machine, and then it will been as he hasn't gone back in time.

Another interesting thing related but different is the idea of time in different intervals. For example, if a ball is thrown into a void that would make it go forwards in time, then the time required for that ball to travel in the void would make it kinda redundant, meaning the time used by the void is from a different reality.

What are your thoughts on Time Travel? I would appreciate and fair, serious dicussion, though I know this is NS General. :rolleyes:

What if you are not the inventor of the time machine, but a user only? I guess it would still apply, since now you wouldn't need to buy your ticket/rent the time machine because what you went into the past to do would already have been done by you so that now you have no need to go back and do what has already been done. Whew!

Time travel to the future is what we all do, every second of our existence.

Backwards is the problem.

What if you could go back in time, and your memory of everything that happened between your target date and the present is erased from your mind?

And going back before your lifetime, how could you exist before you were born? Would that be creating matter in that time that did not previously exist? Or would you have to displace something or someone from back there to the present in order to travel to the past? Maybe you have to exchange places with your past self in order to balance the equation. Or maybe change places with a random person. And when you come back, you appear where they were, which is locked in an insane asylum...

Or if you went into the future via time machine, so that you arrive before the rest of us, that is faster than the normal passage of time, or go to some time far into the future, could you return to the present, which would have become your past? After all, you would not have lived in the time between now and the future time when you appeared, so maybe you could do that...

Brain spinning, spinning out of control, laughing uncontrollably, cackling, people staring, must activate time machine, there, I am going into the future-

The most 'elegant' way that time travel should work[1] is essentially "Everything you go back and do, you have gone back and done".

i.e. the Universe (as observed from outside the timeline) allows a 'loop-back', where someone/something/some information has been torn from the regular flow of time and plugged into an 'earlier' bit of the ribbon, but the spliced in threads of that process purturb the existing threads in such a way to create the weave of the ribbon that forces the serparation of the above threads.

i.e. no splitting of universes[2], no fading Marty McFly through some wierd 'Schrodinger's cat in an open box' situation and no 'timequake' that shifts the awareness and expectations of everyone (but the timetraveller) in the 'present' as soon as the time-traveller returns to their point of departure and finds History changed.

Instead, let's pick how the Grandfather paradox might work under the "self-reinforcing time-loops" theory of a purely causal universe.

At a point in time we shall call 'now', you undergo the process to go back in time with the intention of killing your grandfather (for some arbitrary motive).
Upon your arrival in 'the past', your presence acts to change the environment (air currents divert around you, social interactions exist if you meet people, your time-travelling atoms are shed and rebuilt with 'local' atoms via usual mechanisms with no silly "if an atom touches its past/future self Something Bad Happens (TM)" sort of thing).
You make your attempt on your Grandfather's life, and circumstances are such that you only wound him, and you do not succeed.
This results in a short hospital stay during which time he meets your Grandmother (nurse, visiting someone else, who knows)
Thus, as you travel up the line of time, you get the exact interactions that cause your grandaparents to procreate, their ofsspring to meet your other parent, but your other interactions have also created a 'trickle-down' effect on society and created the social and ideological conditions that pursuade the you at the 'now' point that they ought to go back and try to kill your Grandfather, thus initiating the whole set of events that leed up to you wanting to go back and...


Complex, in various ways, but no paradox.

It would essentially be unfeasible to have a universe in which a time-loop could cause an instability, and yet it would be perfectly possible (even natural) to have a universe in which the only way a time-loop was initiated in the future is because of its 'simultaneous' interaction in the past initiating the cause of the loop in the future.


What a lot of waffle. But I'm writing this blind, not discussing it one-on-one with you, the reader, so I'm not sure I'm hitting the right buttons.


[1] In my opinion,, and even if it is elegant, it needn't be correct....
[2] With the possibility that, when the time-traveller returns to a prior time and forces a new time-line, the entire bit of the universe that was in the future of time-traveller as of his departure is deconstructed by the Time Machine to provide the matter/energy for the 'new fork' in the Universe, as does any other future negated by time-travel back to any other prior point (before or after the original split).

I reckon I can just wait for my future self to come back and teach me how to build one. That way I don't have to worry about it not working.

The most 'elegant' way that time travel should work[1] is essentially "Everything you go back and do, you have gone back and done".Sorry, meant to say that far from being redundant time travel would then (under my scheme) be an essential part of the cause of the time travel.

Hmm, I did this thing about a Rocket, which I will try to find.

Complex, in various ways, but no paradox.


Agreed. "Paradox" is literally the limit of human understanding, in the general sense.

Pretty good post, btw.

I reckon I can just wait for my future self to come back and teach me how to build one. That way I don't have to worry about it not working.
Isn't there a greater statistical probability of you being maimed/buried by an elephant who was constipated until that fateful swab?

As a time travel expert I naturally have an opinion. There are at least 5 ways of dealing with paradoxes as far as I know.

A. Novikov Self-Consistency Principle: When you back in time any change you make has already happened, so in essence you change nothing. For example, if you go back in time and try to shoot your grandpa, it wont work. Your gun will jam or something.

B. An Overwriting Universe: When you go back in time, the universe is reset to that point. The problem with this is that go back to the future is ambiguous. It depends on the actual mechanism which you use to go back to the future.

C. A Form of Fate: Some cosmic destiny reshapes altered events so that they resemble the original. Example: You kill Hitler, one of his lackeys becomes just as evil. This method is crap realistically, it really makes no sense, except in fiction

D. The Universe is Destroyed: This is only useful as a motivator to stop some mad scientist from destroying the universe.

E. An Oscilating Universe: A paradox causes the universe to oscilate back and forth with quantum mechanical mechanisms changing things slightly until the paradox is resolved. In this case you can change history, but it is difficult and potentially dangerous.

Now to be fair, I didn't come up with any of thoes theories. I am merely regurgitating them. Really only A and E are viable.

If I could go back in time, I could prevent myself from damaging my Hemispheres record.

Ugh.

As a time travel expert I naturally have an opinion. There are at least 5 ways of dealing with paradoxes as far as I know.

A. Novikov Self-Consistency Principle: When you back in time any change you make has already happened, so in essence you change nothing. For example, if you go back in time and try to shoot your grandpa, it wont work. Your gun will jam or something.

B. An Overwriting Universe: When you go back in time, the universe is reset to that point. The problem with this is that go back to the future is ambiguous. It depends on the actual mechanism which you use to go back to the future.

C. A Form of Fate: Some cosmic destiny reshapes altered events so that they resemble the original. Example: You kill Hitler, one of his lackeys becomes just as evil. This method is crap realistically, it really makes no sense, except in fiction

D. The Universe is Destroyed: This is only useful as a motivator to stop some mad scientist from destroying the universe.

E. An Oscilating Universe: A paradox causes the universe to oscilate back and forth with quantum mechanical mechanisms changing things slightly until the paradox is resolved. In this case you can change history, but it is difficult and potentially dangerous.

Now to be fair, I didn't come up with any of thoes theories. I am merely regurgitating them. Really only A and E are viable.

C is exactly what Red Alert 2 is based around. Without Hitler, there's Stalin!

Isn't there a greater statistical probability of you being maimed/buried by an elephant who was constipated until that fateful swab?
It all depends on how time works, really. If it works as I think it does, it's theoretically possible for me to learn how to time travel from myself and to then go back and teach myself how to do it, thus ensuring that it happened. In that case, it's a sure thing. But until me from the future shows up, I won't worry about it. ^^;

It's the old paradox of killing you father before you were conceived. One theory says the fact that you are alive means that even if you went back in time specifically to kill your father before you were conceived, you won't succeed. Another theory (impossible to test, it seems to me) is that you split off another dimension when you pull the trigger. This is generally the point at which I give up trying to understand it.

If you want to be SURE about creating a paradox, you should kill your mother.

:)

If I could go back in time, I could prevent myself from damaging my Hemispheres record.

Ugh.
Sorry, current theories about time travle suggest that it would be impossible to go back before the time machine was made, al la that one movie I can't remember.

As a time travel expert I naturally have an opinion. There are at least 5 ways of dealing with paradoxes as far as I know.

A. Novikov Self-Consistency Principle: When you back in time any change you make has already happened, so in essence you change nothing. For example, if you go back in time and try to shoot your grandpa, it wont work. Your gun will jam or something.

B. An Overwriting Universe: When you go back in time, the universe is reset to that point. The problem with this is that go back to the future is ambiguous. It depends on the actual mechanism which you use to go back to the future.

C. A Form of Fate: Some cosmic destiny reshapes altered events so that they resemble the original. Example: You kill Hitler, one of his lackeys becomes just as evil. This method is crap realistically, it really makes no sense, except in fiction

D. The Universe is Destroyed: This is only useful as a motivator to stop some mad scientist from destroying the universe.

E. An Oscilating Universe: A paradox causes the universe to oscilate back and forth with quantum mechanical mechanisms changing things slightly until the paradox is resolved. In this case you can change history, but it is difficult and potentially dangerous.

Now to be fair, I didn't come up with any of thoes theories. I am merely regurgitating them. Really only A and E are viable.Actually, by definition, A, C, and E are viable as pursuits. I don't, however, buy Novikov's idea, since it lacks the integrity required to understand potentiation and the part it plays in deciding timeline paths. D you'd qualified as a deterrent. B, as you'd described here, is interesting. It would stand to reason that there are multiple universes under any other circumstance, since the act of legitimate time travel would assume you had only one universe to interact with at any one point in "time".

It all depends on how time works, really. If it works as I think it does, it's theoretically possible for me to learn how to time travel from myself and to then go back and teach myself how to do it, thus ensuring that it happened. In that case, it's a sure thing. But until me from the future shows up, I won't worry about it. ^^;
The idea though, is that you are alloting faith to fill where experience doesn't.

The argument (and its obvious integral variations) as such:
You haven't reached the point in your life where the future you would find it crucial to inform the current you on how to do it and avoid work ...and/or you haven't actually passed the critical choice alloting you access to the ability to possess such time machine (which, in potentiation, keeps you from fulfilling that role)
.


I'll ask, at this point, how it is you think time works, so i don't get too nebulous.
?

Sorry, current theories about time travle suggest that it would be impossible to go back before the time machine was made, al la that one movie I can't remember.
That would, likely, be a consequence of the nature of time period traversion. It may require a method of movement that is a mode of encapsulation, as inferred by the more fantastic aspects of The Philadelphia Experiment.

Instead, let's pick how the Grandfather paradox might work under the "self-reinforcing time-loops" theory of a purely causal universe.

At a point in time we shall call 'now', you undergo the process to go back in time with the intention of killing your grandfather (for some arbitrary motive).
Upon your arrival in 'the past', your presence acts to change the environment (air currents divert around you, social interactions exist if you meet people, your time-travelling atoms are shed and rebuilt with 'local' atoms via usual mechanisms with no silly "if an atom touches its past/future self Something Bad Happens (TM)" sort of thing).
You make your attempt on your Grandfather's life, and circumstances are such that you only wound him, and you do not succeed.
This results in a short hospital stay during which time he meets your Grandmother (nurse, visiting someone else, who knows)
Thus, as you travel up the line of time, you get the exact interactions that cause your grandaparents to procreate, their ofsspring to meet your other parent, but your other interactions have also created a 'trickle-down' effect on society and created the social and ideological conditions that pursuade the you at the 'now' point that they ought to go back and try to kill your Grandfather, thus initiating the whole set of events that leed up to you wanting to go back and...


I believe they call that the Marty McFly effect.

If you want to be SURE about creating a paradox, you should kill your mother.

:)
If you already existed at that point in time, what difference would it make to kill her? Perhaps nothing.
There's the inferrence of some kind of interventive cosmic judiciousness to set things correct in two different spacetime sets here.
Literally, the act of your mother living is certain to the point of your conception and supposed delivery. Therefore THAT particular line isn't corrupt - it's absolute.
At the point that you could alter an absolute, whatever cosmic balance that supposedly had been in place would have already alotted you the choice and faculty of changing what you perceive as the past. The next step wouldn't be a mechanical response but more of a "balancing" act on part of another entity, not an impersonal reaction to your own action.

I believe they call that the Marty McFly effect.
Hasn't that been updated to the "Philip J. Fry" Effect? :D

Professor Farnsworth: For example, if you killed your grandfather, you'd cease to exist!
Fry: But existing is basically all I do!
-
Professor: "Don't do anything that affects anything. Unless it turns out you were supposed to do it, in which case for the love of God. Don't not do it!"
Fry: "Got it."
-
Fry: "Are you crazy? You almost got yourself run over!"
Enos: "I did? Then I sure am lucky you knocked me onto this pile of rusty bayonets."
-
Professor: "Above all else, it is our secret duty to preserve the past exactly as it was."
Fry: "Well... I killed my grandfather."
Professor: "Whaaaa?"
Leela: "Wait. If you killed your grandfather, why do you still exist?"
Fry: "I don't know. Maybe God loves me?"
Bender: "HAHAHAHAHA!"
-
Fry: *snore*
Leela: "Oh!"
Bender: "Oh my god!"
Fry: *tap* "Eh?"
Professor: "What the hell have you done Fry?"
Fry: "Relax. She can't be my grandmother! I've figured it all out."
Professor: "Of course she's your grandmother you perverted dope! Look"
Mildred: "Come back to bed dery."
Fry: "Waa! It's impossible! If she's my grandmother, then who's your grandfather?"
Professor: "Isn't it obvious? You are!"
Fry: "Aaaaa! Aaaaa! Aaaaa!"

Professor Farnsworth: Choke on that, causality!


------
Yeah, i think that about covers it.

I'm under the impression that it's possible there are infinite dimensions of possibility (I use the word "dimensions" to mean separate universes of existence) therefore the whole "Timetravel would counteract itself" would be moot if going back in time created or affected a different dimension.


That has always been my understanding too. I would argue that the OP situation would assume there could only be one timeline.

I say that if you can travel back into the past, you won't be able to change anything. Like they say in the Hitchhiker's Guide to the Galaxy, "Time Fits Like A Jigsaw!"

Serously, if I went back in time with the intent to kill my grandfather, that would have already been figured into time "before" I left, thus I would fail.

If I could go back in time, I could prevent myself from damaging my Hemispheres record.

Ugh.
http://www.studip.uni-goettingen.de/pictures/smile/geige.gif
;)

The most 'elegant' way that time travel should work[1] is essentially "Everything you go back and do, you have gone back and done".
<snip>
Instead, let's pick how the Grandfather paradox might work under the "self-reinforcing time-loops" theory of a purely causal universe.

At a point in time we shall call 'now', you undergo the process to go back in time with the intention of killing your grandfather (for some arbitrary motive).
Upon your arrival in 'the past', your presence acts to change the environment (air currents divert around you, social interactions exist if you meet people, your time-travelling atoms are shed and rebuilt with 'local' atoms via usual mechanisms with no silly "if an atom touches its past/future self Something Bad Happens (TM)" sort of thing).
You make your attempt on your Grandfather's life, and circumstances are such that you only wound him, and you do not succeed.
This results in a short hospital stay during which time he meets your Grandmother (nurse, visiting someone else, who knows)
Thus, as you travel up the line of time, you get the exact interactions that cause your grandaparents to procreate, their ofsspring to meet your other parent, but your other interactions have also created a 'trickle-down' effect on society and created the social and ideological conditions that pursuade the you at the 'now' point that they ought to go back and try to kill your Grandfather, thus initiating the whole set of events that leed up to you wanting to go back and...

<snip>
Alternatively:

You go back to try and prevent your grandfather's untimely death, but because of the above-stated elegant law, you actually end up causing your grandfather's death.

While comforting his widow, one thing leads to another, and you have sex with her, and thus

You become your own grandpa.

:) (with nod to Futurama)

EDIT: Dammit. Straughn beat me to it.

This discussion is interesting but it will go nowhere if we don't discuss how we think time works -- and space -- and a little bit of physics, too.

Do the rules of matter govern, and would the time traveler thus change form or cease to exist altogether as the atoms that make up his body resolve into whatever form they exist in at the time he is traveling to?

Precisely how would one travel through time? What would that be like, as an experience?

Is it impossible to change history per the "what you do is what you did" rule?

Or can we change history but never know it, as the changes in history change us as well -- i.e., if there was never a Roman Empire, then we would never know there had been/could have been/should have been a Roman Empire, so we'll never know to miss it.

Or does the act of time travel remove the traveler from ordinary historical consciousness, allowing him to know multiple versions of his own history? If so, how would that work, and if he's the only one who knows about the changes, would that make him nuts at all?

Personally, I buy into the "what you do is what you did" theory, which makes trying to change history by time travel an even bigger waste of time than trying to foresee the future through fortunetelling. If you want to know the future, all you have to do is wait. And if you want to change history, all you have to do is rewrite the text books.

But I am working on a time travel concept for a story that approaches the problem from mysticism rather than science. It assumes a certain cosmology and a technique by which a person can view all of space and time -- past, present and future -- like a map and just pick where they want to go, and project themselves into that time and space -- or perhaps bring that time/space to them -- or in any event, close the distance between themselves and it.

Alternatively:

You go back to try and prevent your grandfather's untimely death, but because of the above-stated elegant law, you actually end up causing your grandfather's death.

While comforting his widow, one thing leads to another, and you have sex with her, and thus

You become your own grandpa.

:) (with nod to Futurama)

EDIT: Dammit. Straughn beat me to it.Boo-yaa!
:D
It seemed i was WAAAAAAAAAAAAY behind you, score-wise. I still gotsa ways to go.

But I am working on a time travel concept for a story that approaches the problem from mysticism rather than science. It assumes a certain cosmology and a technique by which a person can view all of space and time -- past, present and future -- like a map and just pick where they want to go, and project themselves into that time and space -- or perhaps bring that time/space to them -- or in any event, close the distance between themselves and it.
Two things for you, if you like ...
the Montauk Project
and
the PRISM project.
Also, After Dark from Art Bell's show deals with a program for this somewhat, although i don't know the name of it.

For movies, try Suspect Zero (certain legit techniques touched upon in it)

Good post, btw. *bows*

I believe they call that the Marty McFly effect.I'd rather not call it that. I would have hoped I would have exhibited obvious contempt for the physical possibility (and I even have some reservations about its fictional value) of a time-traveller gradually 'dematerialising' as he progresses along a path of causation that prevents his own existence.

No, I prefer to think that what happens along the 'normal-line' between past-destination and future-departure obeys physics without such exotic effects (as, of course, must the time travel itself, though here with the prerequisite that an mutual event-horizon needs to be formed between the traveller's 'bubble' of space-time at the point of future-departure and disipated at the point of past-desination)

Ignoring the 'fading' effect as non-sensical (IMHO) in relation to Exomnia's post[1], it would be hard to analyse which of the non-cataclismic events happens (I'd like to exclude that), to any observer without an 'external' view (in meta-time) of the time-line dynamics, but I'd suggest that "OMG, I'm changing time, I must restore it, and when I get Back To The Future (TM) everything will be subtely different" would be a specialised version of the "B" or perhaps "E" (the problem being what happens to the 'new future Marty McFly' who had been experiencing the B1FF-as-lacky existence, did he wander off and get himself lost at an opportune moment or did he go back and create his own branch, or create the reciprocal branch in which 'old Future' Marty' was created, or... or...


But, truly, this is beyond "thinking out of the box" as you need to be able to imagine the appearance of the ribbon of time (or perhaps tapestry, if you're into Norse mythology) and the geometries/topologies that might be visible from this viewpoint.


[1] A = Novikov Self-Consistency Principle[2]; B = Overwriting Universe[3]; C = Fate will overcome; D = Universe is destroyed[4]; E = Oscilating Universe[5]

(Following are longer footnotes, you don't need to keep skipping up and down from, honest.)

[2] I called it a "self-reinforcing time-loop", and another form is the "self-fulfilling prophecy", such as in Macbeth, where (arguably) the information gleaned from the future by the 'drabs' and given to our protagonist gives Lady Macbeth the idea that she not have had that her husband can hurry fate along, and thus cause the event. (Which may not have happened without the intervention.) Compare, though, to the effects, in the Foundation series of Isaac Asimov's "Psychohistory" scholars nudging the future by introducing carefully worded 'predictions', and similar tricks, in order to [I]create the future that they desire (consistent or otherwise with the 'predictions' themselves).
[3] A variant on the 'prune and rebranch' method I described, I suppose. The 'prune' part actually being partially insipred by a short story in which someone 'dimension jumps' across parallel universes, not realising that in order to make the jumps, his 'jump-pack' device destroys the entire Universe he his leaping from, and thus can never find 'his' Universe ever again.
[4] As well as having some psychologic aversion to it, I find this solution to have no elegance. Unless the universe is 'energy neutral', as indeed it might be if all of matter and energy (and 'dark' versions thereof) adds up to zero or perhaps we treat it as a fluctuation that resolves itself at the 'end of the universe' like with particle/anti-particle pairs forming and anhialating in the quantum foam, then what happens to the 'potentia' of the Universe. Which is why I prefer the 'prune and rebranch' version, the potentia of the 'lost future' (probably immediately beyond the time-traveller's future departure) being 'grafted onto' the timeline to create the new direction caused by his 'past arrival'.
[5] The description given seems to me to be essentially a 'resolving universe', where the oscilations dampen down by subtley different effects of the intervention loop back as subtley different causes of the intervention, until a 'happy medium' is created that can be ultimately described under option "A". I have no problem with this, except that the 'oscilations' would surely occur along a time-base independant to that of the time-line itself (meta-time), each frozen 'wobble' of time representing a self-consistent chord between 'past entry N' and 'future departure N+1' until at some point of N<=infinity there is a sufficiently dampened oscilation that it is self-consistent in all ways and 'travelled' by the inhabitants without any other knowledge. The alternative to this (or indeed another possible result) is a 'flip-flop' universe (bi-stable, tri-stable, even poly-stable to a greater degree?) where the 'past entry' into one branch begets a history that creates a 'future departure' initiating a different branch, passing through one (or more) 'entry->departure' cycles until cycling back to initiate the (arbitrarily) 'original' branch.

Time travel simply is I-M-P-O-S-S-I-B-L-E

On that note:
If what you say is true, then if I wanted to travel back in time a few minutes and wack myself with a baseballbat then I would pop up in front of me with a baseballbat and do that, preventing me from ever going back in time?

Alternatively:

You go back to try and prevent your grandfather's untimely death, but because of the above-stated elegant law, you actually end up causing your grandfather's death.

While comforting his widow, one thing leads to another, and you have sex with her, and thus

You become your own grandpa.

:) (with nod to Futurama)

EDIT: Dammit. Straughn beat me to it.

Well, all due credit to Fry, et al, I was imagining a situation in which you knew your Grandfather had not died, as who knows whether you were lied to about who your grandfather was. e.g. You had ended up being/had always been your grandfather, but official family history said that it was actually Hero_Of_The_Great_War who you, travelling back, caused to die under the Clapham Omnibus in circumstances that then forced you to filch his identity in order to escape and then ended up fulfilling 'his' history by meeting Grandma in her younger days and being the 'legend of your Grandpa' up until the point you departed (in time or just conventually fleeing) or actually did die in the trenches of World War One under your supposed Grandpa's identity, all the time him having been buried in an anonymous pauper's grave, as he had all along.

(Or why not have slept with a woman who bore a child she gave up for adoption, that baby being adopted by the couple who were supposedly your biological grandparents but whose reproductive success you had deliberately destroyed in your attempt to non-fatally destroy your own descendence. Or why even go so far as to be your own ancester? Maybe you were unaware that you were only related by adoption to this couple, who had 'always' adopted a child because some bugger had 'always' come back and steralised them both. Even simpler if you had just steralised Grandpa. You had 'always' steralised Grandpa and Grandma had 'always' been made pregnant by her fancy-man.)

As you can see, I'm a great fan in the hand-wavy "There is no paradox here... move along" POV, but I do so like the elegance.

In fact, I think that the elegance is probably harder to maintain if you insist that the solution requires a 'recycled genetic history', but not because of any silly "matter can't meet/touch/be it's own precursor/successor", just that the 'dampened oscilations of differences' version of single-timeline resolution should not be constrained by such sentimental wishes...

Time travel simply is I-M-P-O-S-S-I-B-L-EThat's plain wrong in at least two, possibly three ways...

1) We all travel at 1 sec/sec through time, in a 'classical' sense.
2) Time dilation due to the actions of relativity is observable. An atomic clock carried in a plane circling the world is both affected by the (minisculely) reduced effect of gravity at altitude and the 'relative' motion/acceleration w.r.t. the Earth-bound frame-of-reference (different for east-bound and west-bound circumnavigation, see this physics site (http://hyperphysics.phy-astr.gsu.edu/HBASE/relativ/airtim.html) for details].
3) While the above two, combined, only deal with non-cyclical travel through time, Closed Time-like Curves (simply put, 'loops' in time where an effect can influence events that lead up to their original cause) are not explicitly denied by the known laws of physics and are therefore considered possible. This does not mean that there isn't some unknown limitation that does make them impossible or even that (if possible) they exist in any practical form, but there's no way to say that they are 'I-M-P-O-S-S-I-B-L-E' right now.

The way in which option '3' might be proven impossible is if the required materials (e.g. particles with negative mass) that might be required in such endeavours as maintaining a traversable wormhole (one end of which has been sloshed around fast enough/long enough to undergo time dilation w.r.t. the other end, thus allowing an entrance of an item into the 'sloshed' end to post-date the exit of the same item from the one kept fixed in place, if I'm not getting it the wrong way round) have their possibility of existence quashed by refined measurements of the universe derailing the theories upon which they are bound, but that still does not prevent other methods (massive, fastly counter-rotating cylinder pairs dragging space-time through the space betweenthe, or one of any other number of propsed mechanisms).

On that note:
If what you say is true, then if I wanted to travel back in time a few minutes and wack myself with a baseballbat then I would pop up in front of me with a baseballbat and do that, preventing me from ever going back in time?Maybe you go sideways in space as well in time and don't get to personally get back to your past-self on the back of your head[1], even if you were able to influence ourself in other ways (by, for example, posting messages on the forum the pre-travelled you was reading and thus stimulating them to undergo the activity you seem to have been motivated to do for some reason).


[1] It would be pandering to narrative-causality to suggest that you found yourself in your obsessive neighbour's house, which he'd set up (unbeknownst to you) as a an identical room layout, and hit him on the back of the head under the impression he was you... But I'm sure something similar has s been done as a short story already, anyway... ;)

Two things for you, if you like ...
the Montauk Project
and
the PRISM project.
Also, After Dark from Art Bell's show deals with a program for this somewhat, although i don't know the name of it.

For movies, try Suspect Zero (certain legit techniques touched upon in it)

Good post, btw. *bows*
Thanks, I'll check those out.

I've been trying and failing to find my copy of a Stanislaw Lem story in which Ijon Tichy's space ship is hit by a lima-bean-sized meteor, knocking out navigation. The way the ship is designed, the affected part can only be fixed from the outside by two people, even though this is a single-person ship with only one crew member and one space suit. Thus the ship ends up plunging helplessly into an area full of space-time vortices. Tichy becomes aware of this when, as he is relaxing in an armchair with a book, he comes bursting into the room, yelling at himself and smacks himself in the head with a wrench. As the ship passes through the vortices, the loops of time get more and more tangled on themselves, and more and more Tichys appear in the ship, some separated from themselves by only a few hours or minutes, others by whole stages of life, so that soon there are baby Tichys and elderly Tichys as well as hordes of Tichys aged 20-45, all of whom are fighting with each other over how to fix the damage and who will be in charge of the project -- because that's the kind of guy Ijon Tichy is. Eventually, the problem just stops and Tichy finds himself suddenly alone with himself in a repaired ship exiting the zone of the vortices. He has to figure out what happened. He remembers that, while all the adult Tichys were arguing over parliamentary procedure and whether they had a quorum necessary to vote on how to fix the damage, two boy Tichys snuck out of the room. He figures that the two boy hims must have both gotten into the one space suit and gone out and screwed the loose bits back together, thus solving the problem.

It's my favorite time loop story of all time. It's in this house somewhere.

Well, all due credit to Fry, et al, I was imagining a situation in which you knew your Grandfather had not died, as who knows whether you were lied to about who your grandfather was. e.g. You had ended up being/had always been your grandfather, but official family history said that it was actually Hero_Of_The_Great_War who you, travelling back, caused to die under the Clapham Omnibus in circumstances that then forced you to filch his identity in order to escape and then ended up fulfilling 'his' history by meeting Grandma in her younger days and being the 'legend of your Grandpa' up until the point you departed (in time or just conventually fleeing) or actually did die in the trenches of World War One under your supposed Grandpa's identity, all the time him having been buried in an anonymous pauper's grave, as he had all along.

(Or why not have slept with a woman who bore a child she gave up for adoption, that baby being adopted by the couple who were supposedly your biological grandparents but whose reproductive success you had deliberately destroyed in your attempt to non-fatally destroy your own descendence. Or why even go so far as to be your own ancester? Maybe you were unaware that you were only related by adoption to this couple, who had 'always' adopted a child because some bugger had 'always' come back and steralised them both. Even simpler if you had just steralised Grandpa. You had 'always' steralised Grandpa and Grandma had 'always' been made pregnant by her fancy-man.)

As you can see, I'm a great fan in the hand-wavy "There is no paradox here... move along" POV, but I do so like the elegance.

In fact, I think that the elegance is probably harder to maintain if you insist that the solution requires a 'recycled genetic history', but not because of any silly "matter can't meet/touch/be it's own precursor/successor", just that the 'dampened oscilations of differences' version of single-timeline resolution should not be constrained by such sentimental wishes...
You're familiar with the song, right? "I'm My Own Grandpa"? It's about interbreeding hillbillies, not time travel, but it's still an old joke worth building a cartoon episode around. ;)

The most 'elegant' way that time travel should work[1] is essentially "Everything you go back and do, you have gone back and done".

i.e. the Universe (as observed from outside the timeline) allows a 'loop-back', where someone/something/some information has been torn from the regular flow of time and plugged into an 'earlier' bit of the ribbon, but the spliced in threads of that process purturb the existing threads in such a way to create the weave of the ribbon that forces the serparation of the above threads.

i.e. no splitting of universes[2], no fading Marty McFly through some wierd 'Schrodinger's cat in an open box' situation and no 'timequake' that shifts the awareness and expectations of everyone (but the timetraveller) in the 'present' as soon as the time-traveller returns to their point of departure and finds History changed.

Instead, let's pick how the Grandfather paradox might work under the "self-reinforcing time-loops" theory of a purely causal universe.

At a point in time we shall call 'now', you undergo the process to go back in time with the intention of killing your grandfather (for some arbitrary motive).
Upon your arrival in 'the past', your presence acts to change the environment (air currents divert around you, social interactions exist if you meet people, your time-travelling atoms are shed and rebuilt with 'local' atoms via usual mechanisms with no silly "if an atom touches its past/future self Something Bad Happens (TM)" sort of thing).
You make your attempt on your Grandfather's life, and circumstances are such that you only wound him, and you do not succeed.
This results in a short hospital stay during which time he meets your Grandmother (nurse, visiting someone else, who knows)
Thus, as you travel up the line of time, you get the exact interactions that cause your grandaparents to procreate, their ofsspring to meet your other parent, but your other interactions have also created a 'trickle-down' effect on society and created the social and ideological conditions that pursuade the you at the 'now' point that they ought to go back and try to kill your Grandfather, thus initiating the whole set of events that leed up to you wanting to go back and...


Complex, in various ways, but no paradox.

It would essentially be unfeasible to have a universe in which a time-loop could cause an instability, and yet it would be perfectly possible (even natural) to have a universe in which the only way a time-loop was initiated in the future is because of its 'simultaneous' interaction in the past initiating the cause of the loop in the future.


What a lot of waffle. But I'm writing this blind, not discussing it one-on-one with you, the reader, so I'm not sure I'm hitting the right buttons.


[1] In my opinion,, and even if it is elegant, it needn't be correct....
[2] With the possibility that, when the time-traveller returns to a prior time and forces a new time-line, the entire bit of the universe that was in the future of time-traveller as of his departure is deconstructed by the Time Machine to provide the matter/energy for the 'new fork' in the Universe, as does any other future negated by time-travel back to any other prior point (before or after the original split).


Very well explained, and I tend to agree. I think the movie 12 Monkeys is a perfect example of this Time Travel idea.

One of my pet peeves with Time Travel movies is that many of them won't stick to their own concept of how time travel works. The Back to the Future movies are espescially bad for that.

Assuming that reverse-time travel doesn't harm the space-time continuum, there are several possibilities if such time travel were possible:
1. overwriting history. History is caused by events. If you went back in time and killed those who were responsible for the Holocaust, either something will end up causing it or it never happens. If you go back and kill all the dinos yourself, they were all killed by you and not Mr. Meteor. If you went back and blew up said metoer, time would still continue. You would, in effect, have literally over-written history, since you can't really go to the past. Whatever time you are in will become the present.

2. concrete history. You will have gone back because you already did. This theory states that time is concrete and can never change. The only way you could have saved the dinos or killed Hitler is if you technicly already did.

1+2a. infinite-you conplexity. If you went back in time a certain amount of time, you would have started a chain reaction that will create infinite yous. Metter would not have been created or destroyed in a sense, only moved from time a to time b. You will meet you right when you went back in time, creating another you. This will happen infinite times, unless you somehow stop it. You would have and would not have created matter due to this time movement. This can be prevented by going back further, perhaps to a time way before you were born, in a way, preventing two yous from being in the same timeframe together.

I'm still trying to think about the nature of time, and I am coming from it from a narrative/artistic view rather than a scientific one. I can't do the math to speculate about this scientifically. Here are two thoughts I've had so far. I'd appreciate comments.

[1] Time as linear progression (of what? energy? narrative history?), like a river always flowing in one direction -- yesterday to tomorrow -- and we are in it, and the point we’re at is called “now.” But what are we? Are we like leaves just carried by the current? Or are we like fish swimming in the river? Fish can swim against the current or hold themselves still and let the current flow past them and bring things to them. Why shouldn’t we be able to do the same with time? Fish have techniques for navigating the currents of water. Why can’t there be techniques for navigating the currents of time?

[2] Time as process of material change -- decay, entropy, creation and destruction, etc. This concept is pretty much independent of our time-measuring concepts of “yesterday,” “today”, and “tomorrow.” In this conception, nothing that exists now existed yesterday quite the same because matter is constantly changing, so the beings we are today, we were not yestereday and will not be tomorrow. If this is what time is, then time travel is paradoxical. The universe uses yesterday’s matter to build today’s matter and uses today’s matter to build tomorrow’s. The atoms you are built of now were something else 200 years ago, so if you rewind the process of time 200 years, your matter should re-transform into whatever it was back then. If it does not, then a paradox has occurred. Matter has been deleted from the now-world and exists in duplicate in the 200-years-ago-world. Can that happen? Would that have any significant effect on the structure/function of the universe, or would it be neglible? Can the universe contain paradoxes?

About this story I'm working on, which is, I guess, a third concept of time: The story is about mystics and wizards, and it follows the lore of people like Tibetan lamas and asks, if they do what they say they do, how do they do it? It explores ESP, bi-location, levitation, and all those other paranormal claims, and it focuses on a saying I read, supposedly from some Tibetan master, which has become my favorite life-motto: "Everything is easy to the man who knows how to do it." In other words, there are no impossible things, there are only things we don't know how to do.

While trying to work out this time management aspect, I had a dream about a machine that, by harmonizing energies, brings time and space and all the dimensions and planes of existence into the same perceptual level and projects for the viewer a map of the whole structure of the universe. Using this machine, you can view everything that is, has been, or will be everywhere in the universe. The view is not very detailed (it gets fuzzier the farther it gets from the viewer, just like in regular vision), but it does contain everything. As long as the machine is running, you can just go to ancient Rome exactly the same as you would travel to modern Rome. Time and space work on the same principles of physics. Yesterday becomes a place that exists, not a moment that is gone.

The secret of the machine is that it just reveals a condition that always exists even though we are not aware of it, meaning that this is really how the universe is built -- a backstage view. It’s like an infinite labyrinth of rooms through which we pass. All the doors of the building are locked. They unlock as we come up to them, and lock again behind us as we pass through. The machine, in effect, reveals the labyrinth’s blueprints, including secret passages and shortcuts, so we can plan in advance which doors to go through.

In my dream, the map of the universal structure was an infinitely expanding spiral -- infinite in both its expansion and contraction (infinite outward and infinite inward) -- and all the moments of time were points along the spiral. All you had to do was pick your point, and the path to it would be revealed. In function, I suppose it's similar to Dr. Who's Tardis, but you don't travel in this machine; you depart from it. The path represented by the map was still just a symbol, just like a real map only symbolizes the road it guides you along. With this machine, you have to be able to use the symbolism as your vehicle to make the trip it describes to you.

So this idea of time is really all about perception, then, I guess.

I am not experienced in time travel nor do I know much of it...But I think the multiverse theory is interesting, as well as the theories of Faustian universes (where time flows backwards).

But in a Faustian universe, if both time and progress flowed backwards, wouldn't it be just like this universe? I speak of progress as in this example: In our universe, where time flows forwards, you can still walk backwards if you tried.

So in a different kind of Faustian universe, where time flowed backwards but progress was like this universe, would walking forward or walking backwards seem stranger?

But in a Faustian universe, if both time and progress flowed backwards, wouldn't it be just like this universe? I speak of progress as in this example: In our universe, where time flows forwards, you can still walk backwards if you tried.If the arrow of time and arrow of entropy (assuming that they aren't exactly the same thing, which they might well be) are reversed, then you might well find everything is sdrawkcab, but as everyone looks at everything sdrawkcab it looks like it's the 'right way round' to them.

But I don't want to go on about stuff like domains of reversed entropy in the universe (there was a good article about that in New Scientist a few years back, but I'd have to go through my back-copies to find the reference, I think).

Instead I really want to mention the trollish race inhabiting Discworld (Terry Pratchett's long-running fictional series location) who consider themselves to go backwards through time, because it's only logical that you can see what's in front of you, and not what's behind you, and you can clearly see the (retreating) past and not the (advancing) future. They also talk about the "Sunset of time" instead of "Dawn of time", but that might be because as silicate creatures whose autonomic functions generally shut down in the heat of the day (though that really only applies to those living deep in the mountains, as the ones seen around the main city of Ankh-Morpork seem not to have such a limitation) they may be nocturnal.

I am so glad I'm not (mostly) talking theoretical physics in at least one post in this thread... ;)

I was reading a bit on something by Stephen Hawking (not sure which one), and he talked about how Time Travel to the past would be logically impossible. Here's what he explained:

By travelling to the past, you have effectively curbed the need of travelling to the past, henceforth since you have created the machine, you will have no need to have created the machine, and henceforth you will not have the time machine, meaning you never went back in the first place, meaning you would be stuck at the time you originally were at.

To clear it up a bit, I'm putting an example.

My friend says he wants to take a couple working nuclear devices and go to the times of the Roman Empire, and declare himself God. He says that he will nuke Rome in an effort to make them see him as God. Now, if he used a Time Machine to do this, then he would have gone back in time and done it, henceforth it is changed, therefore he has finished the purpose of what he built the time Machine for, therefore it would register as him not building a time machine at all, henceforth he will not have a time machine, and then it will been as he hasn't gone back in time.

Another interesting thing related but different is the idea of time in different intervals. For example, if a ball is thrown into a void that would make it go forwards in time, then the time required for that ball to travel in the void would make it kinda redundant, meaning the time used by the void is from a different reality.

What are your thoughts on Time Travel? I would appreciate and fair, serious dicussion, though I know this is NS General. :rolleyes:

1. Time only flows one way; forward.
2. The past can affect the future, but the future cannot affect the past.

Add these together and here is the result:
Your friend travels back in time and nukes Rome. He sets himself up as a God, and history is altered. Your friend is likely never born, and he never invents the time machine.
This has absolutely no effect on him though, because he is living in ancient Rome. The fact that he will never be born in the future will not affect him any more than the fact that you will never be born in today's future.
To clarify, you are here now. Will you be born tomorrow? No. Will you be born in a year? No. Will you be born 100 years from now? No.
Does that affect you any? No.
Because things that happen (or fail to happen) in the future do NOT affect the past.
So once your friend is in the past, the entire future can be altered without affecting him one bit.

"But... if he never builds that time machine and travels back in time, won't he just disappear from the Roman time period?"
No. Just like the fact that you will never build a time machine in the future to travel back to the present does not affect the fact that you are here now.
Things that happen or fail to happen in the future do NOT affect the past.

Time travel simply is I-M-P-O-S-S-I-B-L-E

On that note:
If what you say is true, then if I wanted to travel back in time a few minutes and wack myself with a baseballbat then I would pop up in front of me with a baseballbat and do that, preventing me from ever going back in time?
How do we know you didn't do that already and haven't changed your post yet? Besides, you could be making this post under duress.

Thanks, I'll check those out.

I've been trying and failing to find my copy of a Stanislaw Lem story in which Ijon Tichy's space ship is hit by a lima-bean-sized meteor, knocking out navigation. The way the ship is designed, the affected part can only be fixed from the outside by two people, even though this is a single-person ship with only one crew member and one space suit. Thus the ship ends up plunging helplessly into an area full of space-time vortices. Tichy becomes aware of this when, as he is relaxing in an armchair with a book, he comes bursting into the room, yelling at himself and smacks himself in the head with a wrench. As the ship passes through the vortices, the loops of time get more and more tangled on themselves, and more and more Tichys appear in the ship, some separated from themselves by only a few hours or minutes, others by whole stages of life, so that soon there are baby Tichys and elderly Tichys as well as hordes of Tichys aged 20-45, all of whom are fighting with each other over how to fix the damage and who will be in charge of the project -- because that's the kind of guy Ijon Tichy is. Eventually, the problem just stops and Tichy finds himself suddenly alone with himself in a repaired ship exiting the zone of the vortices. He has to figure out what happened. He remembers that, while all the adult Tichys were arguing over parliamentary procedure and whether they had a quorum necessary to vote on how to fix the damage, two boy Tichys snuck out of the room. He figures that the two boy hims must have both gotten into the one space suit and gone out and screwed the loose bits back together, thus solving the problem.

It's my favorite time loop story of all time. It's in this house somewhere.
Not bad, not bad. Unfortunately, i have to scribble some notes on what i shouldn't do with something i'm currently working on. *!*

we can know that time travel to the past will never exist, because we'd know already, as we'd be visited by people from the future.

If I walked up to you in a razzy suit and said I was from the future, would you believe me? :D

Not bad, not bad. Unfortunately, i have to scribble some notes on what i shouldn't do with something i'm currently working on. *!*
Notes about what not to do are the most important notes of all. How many of us wish we had a time machine so we could send back notes to ourselves reading, "Do not drink the seventh margarita"?

If I walked up to you in a razzy suit and said I was from the future, would you believe me? :D
I'd probably say that I did just to see what you'd do next.

(I think I just got another story idea. :) )

Notes about what not to do are the most important notes of all. How many of us wish we had a time machine so we could send back notes to ourselves reading, "Do not drink the seventh margarita"?
Seventh!?!?!?

*starts stomping around the cage and yanking out hair*

Ah, i'd insert a good Memento joke here ... but instead i'll focus on the hair thing. My nostrils need a moderate pruning. ;)

Stephen Hawking is a fool a lucky one at that that made a BS theory that everyone believed and then he racants it but too late he is famous!.

Stephen Hawking is a fool a lucky one at that that made a BS theory that everyone believed and then he racants it but too late he is famous!.
So perhaps he should skip theoretical physics altogether and move into celebrityship of a different nature, like politician or clergyman? (*thinking the latter but also thinking what's the f*cking diff these days*)

I think that time is linear, and we are constantly creating the future, which means we can't go to the future. We would be able to go to the past, but, no matter what we did, the future wouldn't have changed a bit, because what we did already happened. To demostrate my beliefs-

I think that friend would be able to go back in time, complete with the nuke, but something would go wrong, no matter what it was, whether the bomb is a dud or it explodes before you launch it or what. Even if you did manage to change something, you'd come back to realize that it was chronicled even before you went back, without the change you made (the nuke turns out to have been called a meteor that came from the sky to level a city, and caused a sickness to spread into the survivors).

If the arrow of time and arrow of entropy (assuming that they aren't exactly the same thing, which they might well be) are reversed, then you might well find everything is sdrawkcab, but as everyone looks at everything sdrawkcab it looks like it's the 'right way round' to them.


Sdrawkcab.. Are you a Piers Anthony fan by chance?

Seventh!?!?!?

*starts stomping around the cage and yanking out hair*
<snip> ;)
What, did you quit too soon? ;)

Sdrawkcab.. Are you a Piers Anthony fan by chance?While I do like some of his stuff, I must admit ignorance of this reference, which I don't catch.


.sdrawkcab etirw semitemos ot nepah tsuj I

What, did you quit too soon? ;)
Au contraire ... ;)

.sdrawkcab etirw semitemos ot nepah tsuj I
pp.

pp.!sdrawrof sa sdrawkcab yldab sa tsuj epyt nac I

!sdrawrof sa sdrawkcab yldab sa tsuj epyt nac I
!oohooW
!ho'D