The problem with time travel is space travel.

[Gogf]

If time travel were possible, people would be able to use as it as a form of faster-than-light travel. Since that's impossible, so is time travel.

At least that's what I remember from one of Stephen Hawking's books.

 

[NKVD]

I completely disagree. If you pluck something out of a certain time and reinsert it in another time, then you won't have any of this nonsense about moving back through time, you'd be in the future time, then immediately thereafter in the past time.

Furthermore, to suppose that one has to move back through time as though one was moving forward in time would completely negate the point of time travel, as the person would be dead. Our body's survival completely depends on time moving forward.

your body is made of particles which are non-sensitive to time as proved by quantum mechanics. but at which mesure does the law switch to Newtonian physics is still uncertain...so maybe you are right. we should be fixed by 20 years

 

[NKVD]

If time travel were possible, people would be able to use as it as a form of faster-than-light travel. Since that's impossible, so is time travel.

At least that's what I remember from one of Stephen Hawking's books.

not at all...you would theoricaly travel in time by going at 95% of the speed of light. Heck even airliners pilots experience time travel. Certainly not the time travel type of back to the future but a time travel where time slows down. As for faster than light I suggest reading on the EPR principle. It's also theoricaly possible to travel faster than a ray of light using anti-matter by curving the space-time continuum.

 

[Gogf]

not at all...you would theoricaly travel in time by going at 95% of the speed of light. Heck even airliners pilots experience time travel. Certainly not the time travel type of back to the future but a time travel where time slows down. As for faster than light I suggest reading on the EPR principle. It's also theoricaly possible to travel faster than a ray of light using anti-matter by curving the space-time continuum.

That's not time travel, that's a different rate of passage of time. You could theoretically live much longer (relative to an observer on earth) than you should be able to by doing this, but it's not exactly time travel per se.

 

[North King]

If time travel were possible, people would be able to use as it as a form of faster-than-light travel. Since that's impossible, so is time travel.

At least that's what I remember from one of Stephen Hawking's books.

Wormholes are the nifty way around the silly laws of physics.

 

[NKVD]

That's not time travel, that's a different rate of passage of time. You could theoretically live much longer (relative to an observer on earth) than you should be able to by doing this, but it's not exactly time travel per se.

what is it then ? I can give you a formula to calculate that time loss aka time travel...Time travelling in future is easy to do. and that theory is described as time travelling in future. Dont you know the twin paradox of Einstein? When MacFly go in future in Back to the future the one second in his car lasts 20 years for every other people on earth. that's a ''different rate of passage of time'' like you said. Would you say MacFly didnt travelled time?

It's time travelling in the past that's more difficult.

 

[NKVD]

Wormholes are the nifty way around the silly laws of physics.

funnier are Dr. in quantum physics like Kip Thorne writting a whole 500 pages book on wormholes

 

[Gogf]

what is it then ? I can give you a formula to calculate that time loss aka time travel...Time travelling in future is easy to do. and that theory is described as time travelling in future. Dont you know the twin paradox of Einstein? When MacFly go in future in Back to the future the one second in his car lasts 20 years for every other people on earth. that's a ''different rate of passage of time'' like you said. Would you say MacFly didnt travelled time?

It's time travelling in the past that's more difficult.

The farther you are from the center of the earth, the slower time passes, because of the equivalence of gravity and acceleration. Would you say that going to the top of a mountain constitutes time travel?

 

[nihilistic]

Well, technically, at the time you are reading this post you are moving through time at a more or less constant rate. Time moves at different rates due to mass (gravity) distortions but always forward, and supposedly grinds to almost a halt in a black hole's event horizon.

 

[NKVD]

The farther you are from the center of the earth, the slower time passes, because of the equivalence of gravity and acceleration. Would you say that going to the top of a mountain constitutes time travel?

yes. It's the same phenomenon. but the time travel is really not significant. we were talking 95 % and up of the speed of light here. Second, time travel or not since its the same phenomenon I was refering to the original post at least about that time travel problem is the space coordinates. Well if you travel in time or experience a shift in time rate of passage like you said like travelling in a plane or a rocket or a super fast spaceship (all the same phenomenon) you dont fall from the plane nor does the plane have difficulty catching up with the earth movement in the galaxy. Even if you would travel time in a fridge, the fridge have the same momentum as earth. What I find funny is that if you dont travel time like the hollywoodian movies its not time travelling...

 

[NKVD]

's signature...

dude nice quote! lol

 

[Gogf]

yes. It's the same phenomenon. but the time travel is really not significant. we were talking 95 % and up of the speed of light here. Second, time travel or not since its the same phenomenon I was refering to the original post at least about that time travel problem is the space coordinates. Well if you travel in time or experience a shift in time rate of passage like you said like travelling in a plane or a rocket or a super fast spaceship (all the same phenomenon) you dont fall from the plane nor does the plane have difficulty catching up with the earth movement in the galaxy. Even if you would travel time in a fridge, the fridge have the same momentum as earth. What I find funny is that if you dont travel time like the hollywoodian movies its not time travelling...

You're constantly traveling forward in time at the same rate. Relative to eachother, we most likely perceive a slight difference in the passage of time. It's ridiculous to assert that that is time travel, as then the term would have no significant meaning.

 

[mdwh]

You're constantly traveling forward in time at the same rate. Relative to eachother, we most likely perceive a slight difference in the passage of time. It's ridiculous to assert that that is time travel, as then the term would have no significant meaning.

Of course it's time travel - it's time travel into the future.

The thing which we don't know is possible and would cause all the paradoxes is time travel into the past.

In response to the OP - the problem is not with time-travel, it's a problem with jumping from one point in spacetime to another. For example, if you travelled back in time continuously rather than jumping back (as portrayed H G Wells' The Time Machine), then this problem wouldn't occur. But if you're going to teleport, you obviously need to pinpoint a point in space as well as time, because there is no absolute reference system. The concept of "here" has no meaning in the future or past, so you'd have to specify a point in space.

Also, I believe that there is not a consistent defintion of "now" to different observers?

 

[NKVD]

You're constantly traveling forward in time at the same rate. Relative to eachother, we most likely perceive a slight difference in the passage of time. It's ridiculous to assert that that is time travel, as then the term would have no significant meaning.

I suggest that you read a few books on General Relativity...

since time travelling is not having ''a difference of time'' relative to someone else what is it?

 

[Gogf]

I suggest that you read a few books on General Relativity...

since time travelling is not having ''a difference of time'' relative to someone else what is it?

That's not what I meant. We're almost surely at different altitudes (which means we're at different distances from the earth's center of gravity). That means that we perceive time as passing at a different rate for eachother.

 

[NKVD]

not much. maybe i'll win 1 second over 10 years. Still...I experienced the twin paradox compared to you. It means I have ''travelling in time''. If I extend my speed (or gravitational field) i'll maybe win 1 minute this year. If I go real quick i'll finish to win a day on you meaning my wristwatch will be missing a days and months compared to your watch. If I go even faster i'll win years. If we find a way to travel faster than light (which I doubt) well time will go back for me. it's all the same damn thing.

what we should do is first find a suitable definition of ''Travelling in time'' I think its the point we dont agree on rather than the physics. I think that for you travelling in time is only go back. Or only using a immobile cabin. (we could still recreate high speed with gravitrons, if they are confirmed someday)

 

[Millman]

Clarke's Third Law. Any technology sufficiently advanced is indistinguishable from magic. So if someone was observing the past, without having destroyed their own future (an unlikely proposition in and of itself), assuming their technology was stupendously advanced, then they would have no difficulty completely evading us.

Only someone with Godly insight could do that.

Then it looks like you'll have to invent a machine that travels through time taking into calculation space, distance, dimension, and whatever variables are needed to travel. Plus you have to prepare for the practical things like what if you are unable to return because it can't be explained, you forgot extra radio-active substance, or you forgot to feed your cat.

How does the hero manage to remarkably get home but forget to take care of the basic things. Don't answer, I can do that myself.