I have long thought that time travel into the past would be impossible because of the laws of thermodynamics and that pseudo time travel into the future via traveling at relativistic speeds could be possible.

I think that instantaneous time travel in either direction would result in disaster since the universe is expanding. If you travel back into the more dense universe you would implode, and traveling forward you would explode, upon arrival.

I have heard that there have been some seriously considered theories about time travel but I know nothing about them. I was wondering if anyone had any input on the topic.

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The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Why would travelling forward make you explode? It's how we normally travel anyway.

There's probably been a zillion or so threads on this subject, and almost as many opinions expressed. Here's some Wikipedia on the subject: http://en.wikipedia.org/wiki/Time_tr...ast_in_physics

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Traveling forward any significant amount of time would put you in a less dense universe and you would instantaneously expand because there would be nothing to prevent you from doing so.


Oh, by the way, sorry for bringing up topics that other people spoke about before. And thanks for introducing me to Wikipedia... wow... I'm just going to head over there and read from now on. There's no point in discussing anything here because it's all been talked about.

Seeya!

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

I don't understand what you meant by a "less dense" universe. The universe is the universe. If you're talking about universal expansion, that has no preesent effect at the local level. Our planet, solar system, and galaxy are all the same size they were yesterday. It's just galactic clusters that get farther apart.
Oh, no... I've created a monster! Just keep in mind that Wikipedia articles can be edited by anyone off the street, so make sure to check what you read there against other sources.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Dibs on his spot....

FriedPhoton, you might want to look at the discussion of time travel going on right now on this thread: Back to the Future, Part II (nitpicking)

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

If the universe is expanding, what is it expanding into? Beyond the edge of the universe does space exist into which the universe is expanding? If so, what is that space? It must be nothing, which is quite different than the space inside the universe. The sum total of gravity within the universe is expanding outward at the speed of light. Gravity is expanding. If gravity is expanding, then so must all the things held together by gravity. So 100 years ago the universe had something times 100 light years less volume and was more dense, 100 years in the future it will have something times 100 light years more volume and be less dense. Nothing new is being generated in the universe so if it expands, everything within it expands because nothing is filling the voids. It seems fairly obvious to me that those changes in density might cause more than indigestion if you instantaneously travel through time.

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Oh boy, I just opened myself up for an inane argument about semantics. I guess I'll have to correct that.

Gravity does not exist. What we perceive as gravity is the warping of space and time around a mass. So...

If the universe is expanding what is it expanding into? Beyond the edge of the universe does space exist into which the universe is expanding? It must be nothing which is quite different than the space inside the universe which is strongly bent by the mass within the universe. All of the mass within the universe is expanding outward causing the total curvature of space within the universe to decline. If the curvature declines, then the things at the bottom of the gravity well no longer require as much energy to move "upward" in the gravity well. If the ability to move upward in the gravity well improves then the density of mass within the well will decrease as it expands "upward". So 100 years ago... yada, yada, yada.

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Personally I don't see the point in picking out one problematic aspect of time travel in comparison to all the others-- time travel has exactly the same status in modern science as any other "miracle". There is not one shred of evidence that separates traveling into the past from any other miraculous behavior you could care to name, any of them could latch onto some equation of science and make all kinds of apparently impossible claims about the ramifications of that equation.

ZZZzzz...

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

See Wikipedia: Zzz.

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0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0....

It's not expanding "into", it's expanding internally.

If we percieve it, it exists. What you meant to say is "gravity is not a force field" --which is unproven as of yet.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Anyone can say that about anything, obviously. I presume you are objecting to having someone point out that musings about time travel are like musing about astral projection or telekinesis. Not something that skeptics like to hear, I know, but they should not stick their heads in the sand (or a pillow)-- if they wish to have self-consistent views of things.

Actually I feel time travel belongs in the same bucket as metaphysical mumbo-jumbo. I'm not sure why, if someone has put forth a "plausible" theory, that I should not at least look at the theory for a few minutes if only to know it's rubbish and can spread the word.

I heard there was something new, wouldn't even know where to look for it, and figured with all the skeptics floating around here that one or more of you would have heard of a theory getting some kind of serious consideration.

Great conversation though...

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Try having patience. Do you think other posters have nothing better to do than to pander to your thread?

Stimulate the conversation instead of snoring. I've seen more sarcasm here in this thread than on the Rosanne show.

Don't you ever get tired of the people who simply go from board to board finding any detail in postings that may not be 100% accurate and post replies that point out the flaws. I have this image in my head of a couple of old guys that have been around so long that they are bored by life and have no imagination or creativity left in them and hardening of the arteries has assured a complete lack of curiosity about anything because the slight blip on their EKG from getting excited about something might send them off to the big black hole in the sky.

Frequently people come along with an idea or a concept that has excited them and sparked their interest and perhaps to that they have added some creativity of their own and want to share it or clarify it and sure enough a reply will enter the thread that takes the fun right out of the subject.

I'm not sure if these things are posted due to an overcompensation for an inferiority complex or what the problem is, but there is almost ZERO substance to these replies aside from negativity. It's a drag.

Personally I find science and new ideas exciting, and I don't mind reading posts from people who are totally off base if I can see they put some thought into what they said, philosophized a little, and somewhere along the line came up with a new creative idea they want to express. (Of course I'm tolerant of the ignorant, I are one).

I just don't understand the need to stifle people's creativity... and to do it day after day just makes me wonder what the damage is. So, yea, I'm a little frustrated which makes me sarcastic, I'll go take an aspirin and see if it helps.

__________________
The only way of finding the limits of the possible is by going beyond them into the impossible.

Arthur C. Clarke

The Brain Science Podcast

Nope.

__________________
"If this were play'd upon a stage now, I could condemn it as an improbable fiction."
Shakespeare, Twelfth Night
Illuminati's Razor-The most complicatedly evil answer is usually the most correct answer. - Fazor
"Every book is a children's book if the kid can read." - Mitch Hedberg
"Distance doesn’t matter much in space, where if you just start a thing off with the right kind of shove, sooner or later it will get where you want it to go." -Frederik Pohl, Mining the Oort

Yes, I have snapped at folks here for that like a Grumpy Turtle.

Good point.

You know... I feel ya. I really do. Previous comment withdrawn. I admit you annoyed me a bit, but understanding where you are coming from- the annoyance disappears.