# >Time travel is temporarily possible, at low speed :-)

1. Dec 6, 2005

### kleinwolf

>Time travel is temporarily possible, at "low" speed :-)

This is easy : just go west, faster than 40000km/24=1'666km/h...then starting at 0:00 you arrive before the sun at the next parallel and hence before 0:00...but I don't know if it possible to make that sense of humour recharged of fuel for a long time...

Last edited: Dec 6, 2005
2. Dec 6, 2005

### Pengwuino

That's not time travel....

3. Dec 6, 2005

### matthyaouw

I can travel through time. If I lay down and a darkened room and try to relax entirely, I suddenly find that it is several hours later. How cool is that?

4. Dec 6, 2005

### zoobyshoe

I'd be extremely surprised to find there was anyone anywhere who wasn't constantly traveling through time.

5. Dec 6, 2005

### tribdog

oh, there has been a few times late at night when I'd already replied to every post and I could have sworn that time stopped while I waited for someone to reply so I could post again.

6. Dec 15, 2005

time in fact doesn't exsist but only metaphysically can it be proven that it is a man made object to fool the "observer"

7. Dec 15, 2005

### Archon

Ok...Prove it.

8. Dec 15, 2005

### tribdog

I would if I had the time

9. Dec 22, 2005

Prove it huh?

well to prove that itself time exsists is in such a way to prove a wavefucntion properties of time this in its paradoxal form is like proving your exsistence.....Can you prove you exsist? The Ultimate question to every answer.

10. Dec 22, 2005

### Aether

I think, therefore I am.

11. Dec 22, 2005

### rachmaninoff

I think I am; therefore, I am I am.

12. Dec 22, 2005

I think therefor I am?

You know if you really spend some time and thought about it " I think therefor I am" doesn't really prove your exsistence, exsistence realtive to space and time had other atributes to itself concerning you true state of living to non-living. Did you exsist 200 years ago when you great grandparents would have given birth to your grand parents and they giving birth to YOUR parents and you in a state of a pre-exsisting embryo. Think about it.

13. Dec 22, 2005

### Pengwuino

I am.... yet i don't think much.

14. Dec 22, 2005

### SpaceTiger

Staff Emeritus
This totally ignores the grandfather paradox. If, using your method, I travel back in time and kill my grandfather, there's just no way I'll be able to get back and deposit his money into my account before the bank closes.

15. Dec 23, 2005

### Smurf

Fallicious argument. In order to think you first have to exist so that sentence is really saying "I exist, therefore I exist". That's begging the question.

You also used it wrong, Descartes used all of it as a premise, not as an argument in it's self. He later changed it to "I am, I exist." to clear up the misunderstanding because people kept thinking he was infering something.

Joke time!

Descartes is sitting in a bar, having a drink. The bartender asks him if he would like another. "I think not," he says and vanishes in a puff of logic.

Last edited: Dec 23, 2005
16. Dec 23, 2005

### Aether

OK, you are correct.

So, after considering everything very thoroughly, I must finally conclude that the proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind. -- Descartes

17. Dec 24, 2005

### honestrosewater

If you take 'I think, therefore I exist', or 'P | Q', as an argument with 'P' as the premise and 'Q' as the conclusion, it certainly can't be circular because it isn't valid. However, if you add the premise 'P -> Q' (P implies Q), as you did in asserting that in order to think you first have to exist, it becomes an instance of Modus Ponens, '(P -> Q), P | Q', which isn't circular. You are correct, in a way, that '(P -> Q), P | Q' and 'Q | Q' are saying the same thing in that they are both valid arguments and have corresponding tautologies and theorems in classical logic. '(P -> Q), P | Q' becomes '(((P -> Q) & P) -> Q)' and 'Q | Q' becomes '(Q -> Q)'. In the same way, 'P | Q' corresponds to '(P -> Q)', which is what I had always thought he was asserting. But it seems he was just saying that 'Q' is a performative tautology, i.e., that 'I exist' is always true when the thing that 'I' refers to asserts that 'I exist' is true. Makes me wonder what kinds of things can make assertions. I mean, my printer doesn't make an assertion when it prints 'I exist'... or does it? hmmm...

Um, and I might incur the wrath of the stupid joke gods, but that joke seems to rely on the fallacy of denying the antecedent, '(P -> Q), ~P | ~Q'. Or maybe that was the joke. hmmm...
Now, if he had said 'I do not exist'... :rofl: Yeah. Good stuff.

Last edited: Dec 24, 2005