Time Travel

[Limewater]

can you formulate a proof showing that time travel is not logically possible?

Time travel is not possible. Time is something that keeps on going. Time has nothing to do with speed. I know about the tests with planes flying around the world and the clock showing some differences. I just don´t believe in that. Those tests are flawed.
The next minute is really the next minute.

Even if the entire galalxy would be frozen for 1 hour that would not mean that time was stopped. it would simply mean that the galaxy was frozen for 1 hour.

OK. So, in other words, you cannot formulate a proof; you just believe it really, really hard. You might want to soften your language, then. I mean, the Axiom of Choice is not provable, either. Almost everyone believes in it, but people don't go around saying that it is not possible for the Axiom of Choice to NOT be true. By claiming that something is not "logically possible," you are implying that your claim has a basis in mathematical logic. Your claim may-- but your following statement makes clear that you are unaware of one.

Formulating proof against the possibilty of time travel is ludicrous. I know it is not possible.
why is not possible you ask? Simple.
Matter/energy can not dissappear. traveling into or back into the future would mean matter/energie would dissappear. That´s impossible.

No, you are incorrect when you say that traveling backwards or forwards in time would mean that matter or energy would have to disappear. I don't personally have a problem with the idea of breaking the first law of Thermodynamics, but in this case it is unnecessary.

I do find it amusing, however, that you spend the first half of your post claiming to not believe in a good chunk of modern Physics, but you then continue to justify your position by appealing to the First Law of Thermodynamics. I have my own personal skepticisms as well, which is why I attempt to add disclaimers such as "according to current theory" and stuff to my direct comments.

But there are a couple of reasons to disagree with you. If you accept that the passage of time is linked to space (or the first derivative of space), then travel through time requires a displacement in space. Time travel becomes a mere spatial displacement of matter. Nothing has to cease to exist.

Alternatively, and the following may be crap, since I'm to the point of extrapolating on my own and I'm pretty rusty on my serious study, one could also view a framework of stationary time travel not violating the first law of thermodynamics. The first law applies to a closed system. It was written under the assumption that our universe is a closed system. A temporal shift does not necessarily mean that matter has been created or destroyed. It just exists at a different time within the closed system. The second law of thermodynamics is regularly "violated" by a local decrease in entropy. This is offset, however, by the increase in entropy (energy expenditure) required to decrease the entropy in that locality. This would be the same thing, but with the first law of thermodynamics and locality in time rather than space.

[Inazuma]

@Limewater
You got it backwards. When someone puts forth an idea (such as time travel) that's hard to believe, it's their responsibility to prove it.

This is how you sound to me:

Limewater - "Hey guys. It's possible for dogs to transform into dragons and fly at speeds up to 700 MPH through the sky."

Average Joe - "What? That's impossible!"

Limewater - "It's your job to prove that it's impossible, and if you can't do so, that means it's possible."

[Limewater]

@Limewater
You got it backwards. When someone puts forth an idea (such as time travel) that's hard to believe, it's their responsibility to prove it.

This is how you sound to me:

Limewater - "Hey guys. It's possible for dogs to transform into dragons and fly at speeds up to 700 MPH through the sky."

Average Joe - "What? That's impossible!"

Limewater - "It's your job to prove that it's impossible, and if you can't do so, that means it's possible."

No, not quite. I am not saying, "Time travel is possible." I'm saying, "Time travel may be possible." Others have said, "Time travel is impossible."

The burden is on the person making the stronger claim. My claim that is may be possible (in other words, that I am not willing to say that it is impossible) is pretty weak. d123456's claim that time travel is not logically possible is very strong. By making the absolute determination, he accepts the burden of support.

If I did say "Time travel is possible," show me where I did and I will apologize.

[Inazuma]

@Limewater
You got it backwards. When someone puts forth an idea (such as time travel) that's hard to believe, it's their responsibility to prove it.

This is how you sound to me:

Limewater - "Hey guys. It's possible for dogs to transform into dragons and fly at speeds up to 700 MPH through the sky."

Average Joe - "What? That's impossible!"

Limewater - "It's your job to prove that it's impossible, and if you can't do so, that means it's possible."

No, not quite. I am not saying, "Time travel is possible." I'm saying, "Time travel may be possible." Others have said, "Time travel is impossible."

The burden is on the person making the stronger claim. My claim that is may be possible (in other words, that I am not willing to say that it is impossible) is pretty weak. d123456's claim that time travel is not logically possible is very strong. By making the absolute determination, he accepts the burden of support.

If I did say "Time travel is possible," show me where I did and I will apologize.

OK, so it may be possible for dogs to transform into flying dragons. It's your job to back that up, not our job to disprove it. Otherwise we can have any random asshole coming up with insane possibilities.

Maybe the dog example was a bad choice, since that one may be possible at some point. If science advances enough we may be able to tweek genetic code and end up creating our own modified lifeforms. Time travel will never happen because time doesn't exist. We can come up with ways to move really really fast or modify the human lifespan, but we can't interact with time in any way since it doesn't exist in the first place.

[J T]

Inazuma is getting at the point that a hypothesis has to be falsifiable. It's basic science methodology. Still, to say something is impossible generally isn't very scientific either. It's better to say "the evidence does not support the idea".

[Limewater]

Inazuma is getting at the point that a hypothesis has to be falsifiable. It's basic science methodology. Still, to say something is impossible generally isn't very scientific either. It's better to say "the evidence does not support the idea".

Yes. I have not stated a hypothesis. Stating that time travel is NOT possible is a hypothesis. Saying "I don't know" is saying, "I don't know". If something may be possible, it may not be possible. All I have done is shoot down the statements of others who have taken a hard line. I didn't even really get into it until people started talking about the "logic" of time travel, implying that the conclusion could be reached via some mathematical methodology.

Inazuma is getting off on some strange tangent, trying to talk about "proving" things in science. If you want to prove things, do math.

@Inazuma:

Saying, "Time travel may be possible" is not a statement that needs any support. It is a statement that I do not believe there is enough data to say with absolute certainty either way. There could be a 99.99% chance it is impossible and a 0.01% chance it is possible. Any mathematician would tell you that is not sufficient to make an absolute statement.

But if you don't want to believe that time exists, that's fine. You don't have to. Nobody will make you. It certainly doesn't appear to exist in the exact same way that that space exists. My statements, as I believe I have mentioned several times, are based upon my understanding of currently-accepted Physics theory. Flatly saying, "Time does not exist" is not really in line with my understanding of currently-accepted Physics theory. That strikes me as similar to saying "centrifugal force does not exist" or "imaginary numbers do not exist."

[d123456]

To be honest I do not understand half of what was written. I do not know any of these science terms.
Yet I know time travel is not possible.
Stating that it is not save to state something like this is like saying that the verb knowing should never be used. Nothing in life is certain. Nobody knows anything for certain. When someone says they know something it actually means they think that with a high level of probability.
I can not really prove that it is impossible, but how can one prove anything to be impossible? It´s very difficult to prove anything to be impossible. Proving things to be possible is done all the time.
-Time does not exist-
I never really though about that, but that seems like a good explanation.

Great thread guys!

[Limewater]

Yet I know time travel is not possible.

It sounds more like you think you know that time travel is not possible.

Nothing in life is certain. Nobody knows anything for certain.

Yes.

When someone says they know something it actually means they think that with a high level of probability.

Then why don't they say that?

I wasn't actually picking on anyone for saying the "know" something. If you want to say that you know that the toothfairy watches you through the window every night, I won't give you crap. I was picking on you because you said something was "logically impossible."

I can not really prove that it is impossible, but how can one prove anything to be impossible?

In a mathematical context, there are lots of ways. Proof by contradiction is a common and popular method.

[d123456]

hah, a friend send me this
http://www.pbs.org/wgbh/nova/time/think.html
I don´t buy it.
Time travel might be possible because of some thing to do with a very high speed? Yeah right!
The only thing that speed will do is get you there quicker. (no, not like that!)
Speed of light always the same? speed compared to what?
The speed of light is probably restricted by friction (i hope that´s the correct term)
to the bystander the light is going at 186,050 mps

[Mod_Man_Extreme]

hah, a friend send me this
http://www.pbs.org/wgbh/nova/time/think.html
I don´t buy it.
Time travel might be possible because of some thing to do with a very high speed? Yeah right!
The only thing that speed will do is get you there quicker. (no, not like that!)
Speed of light always the same? speed compared to what?
The speed of light is probably restricted by friction (i hope that´s the correct term)
to the bystander the light is going at 186,050 mps

What?



Go back to school now.