Does the Law of Conservation of Matter/Energy Disallow Time Travel?

[KUSA]

Does anyone here believe that the past exists?

If you board the Starship Enterprise, you could leave earth's orbit at warp speed and look back to earth and see yourself boarding.

True but that has nothing to do with going back to the past. It is just light that reflected off you in the past.

[IATIA]

True, but if we stand face to face, all I see is the light reflected off of you. Back to your original question, I do not know, QM suggests the possibility, but if it were true and the past exists, so does the future which makes us just a shadow of what has already happened.

[KUSA]

True, but if we stand face to face, all I see is the light reflected off of you.

Again this is true. However, just because you are looking at light that is reflected off a past event doesn't mean the past event is still there.

This is an interesting video of how we perceive what the present is.

http://youtu.be/K4vyRvMASPU

[Brian37]

In what context because time travel already exists. When you observe the sun, you are seeing it as it existed 8 minutes in the past. Those in orbit on the space station are subject to their own personal time.

I don't see right now how the si fi stuff of say going back and killing Hitler happening though. You are still talking about the problem of complexity at a quantum level and energy input vs output problems.

[LostLocke]

I don't see right now how the si fi stuff of say going back and killing Hitler happening though. You are still talking about the problem of complexity at a quantum level and energy input vs output problems.

Exactly. The first problem is that we don't know that time travel into the past is even possible. So far, it looks extremely unlikely.
Then, even if it is possible, we don't know that as a species we'll be around long enough to develop the tech for it. That's something Kaku keeps mentioning... If time travel is possible, no one has come from the future to tell us so, which looks pretty bleak.

The thing I do like is the "philosophy" about past time travel. Out of all the schools of thought, the one I tend to like the most for no particular reason (and for the life of me I can't remember what it's called ), is the idea that the past's history already includes people going back to try and change it. Like with Hitler, his history is "complete", and any attempt to travel back and kill him is already part of that history.

[KUSA]

Time travel is woo just like God.

[Joods]

My other half, who completely understood the first page of posts I read to him said it sort of sounds like that show Quantum Leap, where you go back in time, but you're sharing a body with someone else. Your physical body no longer exists, but your energy goes into another person, you see through their eyes and go through their daily routine but you can alter certain paths that they take to put them on a better (or worse) path. Once your mission is complete, you leap again.

However, he says, you may be only able to go through your own geneology to do it. In other words, you'd have to be related to the person your leaping to. At least that's what he would think. *

*disclaimer: Those are his words not mine. He hasn't joined these forums because he can't type (or spell) worth shit and I'm the faster typer. He's a hunter and pecker while I crank out 93wpm.

[LostLocke]

Time travel is woo just like God.

I'm not ready to write off time travel as 'woo' just yet.
The fact that it's not a constant and can do funky stuff as relative might have seemed woo-ish to some people not even 200 hundred years ago.
We're already living in an era where the idea that an effect can occur before a cause is plausible.

[KUSA]

I'm not ready to write off time travel as 'woo' just yet.

It's woo.

The fact that it's not a constant and can do funky stuff as relative might have seemed woo-ish to some people not even 200 hundred years ago.

I think most people have a misconception of what time is. It's a "thing" to them. They can put it in a device and shoot chroniton beams at something. It's not a thing. It is just entropy of the universe in action. "Time" only flows forward and never in reverse. Different things such as speed and gravity effect the rate of time but they only slow it down. It never reverses.

Humans record events and moments and stitch them together like a video tape. It seems like it is a thing but it's not. The complexity of the mind that gives you this feeling is not too different than the feeling of God. The brain talks to itself and people think there is a god. It's all woo.

Now with that said, I love a time travel show. The Enterprise zooming around the sun and picking up whales in the past makes a good show. I can suspend my reason long enough to enjoy the show. I can do this with ghost movies too. It's fun.

We're already living in an era where the idea that an effect can occur before a cause is plausible.

I'm skeptical about that.

[IATIA]

If time travel is possible, no one has come from the future to tell us so, which looks pretty bleak.

I am sure there would be a "Prime Directive", the butterfly effect and all.