phil

someone wanted to know my thougts on time travel, so here's the thread! As always, anyone's opinions on the subject are welcome.

Ok, time travel. First, I will make a couple assumptions:
ASSUMPTION 1: Time (duration) only has meaning if there is cyclical behavior of matter and/or energy.

ASSUMPTION 2: The cyclical behavior of matter and energy is governed by electric permittivity (e) and magnetic permeability (u).

Theoretically, if you could build a device that could alter (e) and (u), you could control time because you are controlling the cyclical behavior of all matter and energy.

Here is how such a device would behave. Say your device can make a "bubble" of space and can control time within that bubble. If you were in the bubble and slowed time for yourself, you would see everything moving at an incredible rate (you would "travel" forward in time). If you speed time up for yourself, everything would move incredibly slow (you would "slow" time for everyone else).

Traveling backwards in time is much more complicated, and would take much more power. I will not take the time to discuss it here.

Those are a few thoughts from me on time travel. It is much easier said than done, though. No one knows exactly how to alter (e) and (u) of space at will. Perhaps someday someone will find out.

-phil
PS There is another, perhaps "easier" way to "travel through time" and I may post it later.

Mageth

(you would "travel" forward in time)

Hey, I'm traveling forward in time right now.

phil

The funny thing about time is that it is always the present. Go fast, slow, backwards, forwards, and it's still the present! (from the observer's point of view, of course)

ahh! I'm being stalked by the present!

-phil

Godless Wonder

Back when I was a kid, 1984 to be exact, (I remember because of the Van Halen album, and because as you'll see, it's important that I remember it) I made a deal with myself as an experiment. If I ever get a chance to ride in a time machine, I am supposed go back to 1984 and inform myself of some good stock tips from the future Well, the end of 1984 came and went... no stock tips were forthcoming, good or bad. I guess I never will have had gotten* to ride in that time machine... oh well.

* note the use of advanced time-travellin' savvy verb tense. :-)

sophie

If you are proposing time travel you should be able to amplify your ideas simply in both the foward and backward directions. Should you not?

Why are you sure you will see the world flash by, is it not possible you may become blind to the rest of reality?

phil

Actually, backwards time travel is always more difficult than forwards, no matter how you view time.

With relativity, all you have to do to travel forward in time is travel at a speed close to that of light. However, backwards time travel requires a speed faster than light.

I think you would agree that it is easier to travel close to lightspeed than it is to travel faster than lightspeed.

I cannot say what time travel would look like because I've never done it. All I can do is hypothesize. It is quite possible that a great many strange things could be felt, seen etc. if one time traveled.

Just like the question of 'how many licks does it take to get to the center of a tootsie pop?' the world may never know

-phil

Apocolips

Hola!

Time travel to the past is impossible. What happened has happened and no one can change it. Going into the past would be absolutely wonderful, because one could repair tragedies, (for example, go back to 1888-1889 and kick Hitler's mother in the stomach), but maybe changing the future may have some more dire consequences. Anyway, if people from the future can come to the past, the current time would be changed all the time, we would wake up and watch the Today show to hear about the death of former two term President Kennedy at the age of 86.

Now, traveling in the future is possible, but only if someone can invent a machine that travels faster than the speed of light. The time will not change for you, but will move fatser on Earth. Einstien dreamed this up. Problem is that it is impossible to build a craft to support a human that will go faster than the speed of light, which makes the argument a moot point.

SENOR:boohoo: :boohoo:

sophie

Phil, in a previous post you claimed In answer to my questioning, you replied

and further if you feel this is the generalisation :

then why would you propose a discussion on time travel?

Sylvan Wizard

Of course you're making a number of assumptions you're not stating, though you should. I do not see why time travel to the past is necessarily impossible. Difficult perhaps, but impossible, no.
Surely you can think of a better way.
Oh? why's that? There are difficulties to overcome to be sure, but once again, why would it be impossible?

mnkbdky

Senor stated that time travel is impossible (at least backwards). However, (s)he never gave any reasons why (s)he thought/thinks so. Perhaps, this is just his/her opinion. If so, I believe (s)he opines correctly (though, (s)he was incorrect about forward time travel). There is, however, a big difference in the world of epistemology b/t a correct opinion and knowledge. In fact, this might be just another example of the Gettier problem. Nevertheless, I do agree with him/her that time travel is impossible (though, I suggest, it is impossible whether backwards or forwards). Let me explain why.

Leibneiz's Law or the Law of the Indiscernibility of Identicals states: A is identical to B if and only if for every property B has A also has it and vice versa.

To explain a little further: If A is identical to B, that is, if A has every property that B has and vice verse and both A and B have the property of being self-identical, then A has the property of being self-identical with B and B has the property of being self-indentical with A, in which case A is B and B is A (i.e., A=B and B=A). If this is the case, then, in reality there is only one object.

Now, let's say I am petting my dog, Mango (M), on the couch at time T1. Then at T2 I decide to put (M) into a time machine and have her travel back to when I was petting her on the couch at T1. After her arrival we now have two Mangos, (M) and (M*) respectively. This is impossible.

(M) is the same dog as (M*), right?. That is, (M) did travel through time and, therefore, (M)=(M*). But if (M) is the same dog as (M*), then, (M) and (M*) are identical. However, if (M) is identical to (M*), then (M) and (M*) have every property that the other has including self-indentity. That is, (M) is (M*) or (M)=(M*) and vice versa. But if (M)=(M*) and vice versa, then, there is only one object or one dog. Clearly, though, there are two dogs. Therefore, we are forced to say that (M) is not (M*) or (M)=/(M*). And if (M)=/(M*), then, (M) did not travel through time. However, didn't we just state above that (M) did travel through time and, thus, (M)=(M*)?

In conclusion, time travel results in a contradiction, namely, (M)=(M*) and (M)=/(M*). All contradictions are false, in fact, contradictions are necessarily false and anything that in necessarily false is impossible. Therefore, since time travel results in a contradiction time travel is necessarily false and, hence, impossible.

Thanks,

simul iustus et peccator
MNKBDKY

p.s., please forgive any grammatical or spelling errors, I took a pain killer for a migrain (oxycontin) and am not exactly myself--though I still have the property of being self-indentical.

p.s.s., this argument also applies to traveling forward in time, just make the necessary changes.