Cunting Scientists Piss on Time Travel

[mistermack]

How come going faster than the speed of light would help you travel through time anyway? It it proved, or just postulated?

[Gawdzilla Sama]

How come going faster than the speed of light would help you travel through time anyway? It it proved, or just postulated?

It's just a check off item. One of the things you'd have to do to travel in time, exceed the speed of light. As I understand it anyway.

[Xamonas Chegwé]

How come going faster than the speed of light would help you travel through time anyway? It it proved, or just postulated?

As you get closer to the speed of light, time slows down - ie. the rest of the universe goes slower and slower. At the speed of light, time in the world outside stops. The implication is that exceeding the speed of light would thus cause time to go backwards. Not something you could actually observe though - unless you're friends with a photon with a camcorder!

[Xamonas Chegwé]

A second thing that happens as you approach c, is that the universe compresses in the direction of travel until, at c, it has no thickness and is a completely flat plane. This would imply that, at hypothetical speeds above c, it would not only run backwards but invert, so you would be travelling through a mirror image universe!

[laklak]

so you would be travelling through a mirror image universe!

So I'd have a minge instead of me old John Thomas? Hmmm....

[devogue]

so you would be travelling through a mirror image universe!

So I'd have a minge instead of me old John Thomas? Hmmm....

No, you'd have a giant cock.

[Xamonas Chegwé]

so you would be travelling through a mirror image universe!

So I'd have a minge instead of me old John Thomas? Hmmm....

No, you'd have a giant cock.

But it would come out of your backside and your arsehole would be in front.

[mistermack]

If you travel at the speed of light, time stops FOR YOU. But in reality the rest of the world ticks on at the same rate. So if you went past the speed of light, time for you might go into reverse. But it wouldn't force time to reverse for the rest of the universe.
So you might get younger, but the rest of the Universe would keep on getting older.
You aren't really TRAVELLING through time, you're just reversing your own processes.
( I think ).

[Xamonas Chegwé]

If you travel at the speed of light, time stops FOR YOU. But in reality the rest of the world ticks on at the same rate. So if you went past the speed of light, time for you might go into reverse. But it wouldn't force time to reverse for the rest of the universe.
So you might get younger, but the rest of the Universe would keep on getting older.
You aren't really TRAVELLING through time, you're just reversing your own processes.
( I think ).

Not quite. From the POV of an outside observer, your time would slow to zero. From your POV, time would progress as normal but everything else in the universe would slow to zero. That's why it's called relativity - it all depends on where you're standing and how fast you are travelling relative to other things - if you are travelling at c, it is equally valid to say that you are stationary and the rest of the universe is moving at c.

So, theoretically, if you travel beyond c, you would observe time going backwardsin the rest of the universe but an observer there would see you travelling backwards in time. What does this mean? Fuck knows! It can't happen as far as we know - it's just a thought experiment that leads to nasty paradoxes and maths with infinities in it. Still; fun to speculate though..

[Cormac]

If you travel at the speed of light, time stops FOR YOU. But in reality the rest of the world ticks on at the same rate. So if you went past the speed of light, time for you might go into reverse. But it wouldn't force time to reverse for the rest of the universe.
So you might get younger, but the rest of the Universe would keep on getting older.
You aren't really TRAVELLING through time, you're just reversing your own processes.
( I think ).

Not quite. From the POV of an outside observer, your time would slow to zero. From your POV, time would progress as normal but everything else in the universe would slow to zero. That's why it's called relativity - it all depends on where you're standing and how fast you are travelling relative to other things - if you are travelling at c, it is equally valid to say that you are stationary and the rest of the universe is moving at c.

So, theoretically, if you travel beyond c, you would observe time going backwardsin the rest of the universe

but an observer there would see you travelling backwards in time. What does this mean? Fuck knows! It can't happen as far as we know - it's just a thought experiment that leads to nasty paradoxes and maths with infinities in it. Still; fun to speculate though..

I believe it is to do with velocity, acceleration, and spacetime. It turns out that the fastest trip between two point is by the accelerated route. So, when you arrive back, you've travelled further, but for you, less time has passed than for the person who stayed behind. This operates with GPS satellites where the on board clocks are designed o run more slowly than the GPS units on earth, so that positioning calculations will be accurate.

[Xamonas Chegwé]

If you travel at the speed of light, time stops FOR YOU. But in reality the rest of the world ticks on at the same rate. So if you went past the speed of light, time for you might go into reverse. But it wouldn't force time to reverse for the rest of the universe.
So you might get younger, but the rest of the Universe would keep on getting older.
You aren't really TRAVELLING through time, you're just reversing your own processes.
( I think ).

Not quite. From the POV of an outside observer, your time would slow to zero. From your POV, time would progress as normal but everything else in the universe would slow to zero. That's why it's called relativity - it all depends on where you're standing and how fast you are travelling relative to other things - if you are travelling at c, it is equally valid to say that you are stationary and the rest of the universe is moving at c.

So, theoretically, if you travel beyond c, you would observe time going backwardsin the rest of the universe

but an observer there would see you travelling backwards in time. What does this mean? Fuck knows! It can't happen as far as we know - it's just a thought experiment that leads to nasty paradoxes and maths with infinities in it. Still; fun to speculate though..

I believe it is to do with velocity, acceleration, and spacetime. It turns out that the fastest trip between two point is by the accelerated route. So, when you arrive back, you've travelled further, but for you, less time has passed than for the person who stayed behind. This operates with GPS satellites where the on board clocks are designed o run more slowly than the GPS units on earth, so that positioning calculations will be accurate.

Very true. Any two bodies in relative motion will experience time moving at different rates. This is because everything moves through spacetime at c - spacetime being the usual spacial dimensions combined with that of time - if you increase your motion through space, your total speed has to remain constant, so your progress through time is necessarily reduced.

The Satellite thing is more complex. It involves gravity and its equivalence to acceleration, according to Einstein's general theory of relativity. Gravity warps space and time in such a way that objects under the influence of gravity are equivalent to those under acceleration - the stronger the gravity, the greater the equivalent acceleration. Since gravity increases as you approach a massive object, the closer you are to such an object, the slower time moves - hence, time is faster on satellites which are further from the Earth's gravitational field. Of course, from the POV of someone living on a satellite, time moves at exactly the same rate as it does on Earth - it is only when you compare watches after a period of separation that any difference would be noticed.

[Cormac]

If you travel at the speed of light, time stops FOR YOU. But in reality the rest of the world ticks on at the same rate. So if you went past the speed of light, time for you might go into reverse. But it wouldn't force time to reverse for the rest of the universe.
So you might get younger, but the rest of the Universe would keep on getting older.
You aren't really TRAVELLING through time, you're just reversing your own processes.
( I think ).

Not quite. From the POV of an outside observer, your time would slow to zero. From your POV, time would progress as normal but everything else in the universe would slow to zero. That's why it's called relativity - it all depends on where you're standing and how fast you are travelling relative to other things - if you are travelling at c, it is equally valid to say that you are stationary and the rest of the universe is moving at c.

So, theoretically, if you travel beyond c, you would observe time going backwardsin the rest of the universe

but an observer there would see you travelling backwards in time. What does this mean? Fuck knows! It can't happen as far as we know - it's just a thought experiment that leads to nasty paradoxes and maths with infinities in it. Still; fun to speculate though..

I believe it is to do with velocity, acceleration, and spacetime. It turns out that the fastest trip between two point is by the accelerated route. So, when you arrive back, you've travelled further, but for you, less time has passed than for the person who stayed behind. This operates with GPS satellites where the on board clocks are designed o run more slowly than the GPS units on earth, so that positioning calculations will be accurate.

Very true. Any two bodies in relative motion will experience time moving at different rates. This is because everything moves through spacetime at c - spacetime being the usual spacial dimensions combined with that of time - if you increase your motion through space, your total speed has to remain constant, so your progress through time is necessarily reduced.

The Satellite thing is more complex. It involves gravity and its equivalence to acceleration, according to Einstein's general theory of relativity. Gravity warps space and time in such a way that objects under the influence of gravity are equivalent to those under acceleration - the stronger the gravity, the greater the equivalent acceleration. Since gravity increases as you approach a massive object, the closer you are to such an object, the slower time moves - hence, time is faster on satellites which are further from the Earth's gravitational field. Of course, from the POV of someone living on a satellite, time moves at exactly the same rate as it does on Earth - it is only when you compare watches after a period of separation that any difference would be noticed.

Is gravity, in relativity an artefact or side effect of motion in spacetime?

(I'm reading a book on all this at the moment but have to admit that it melts my brain.

[Xamonas Chegwé]

Gravity is a property of matter. Anything and everything that has mass, exerts gravity on everything else. The gravity exerted is proportional to the mass of the object and inversely proportional to the square of the distance from the object.

Gravity warps spacetime, so that anything moving through spacetime in the proximity of a massive object has its trajectory (through both time and space) altered by gravity.

And beyond that, my brain starts to melt too! I haver pretty much got a grasp on special relativity but GR is a much bigger and more confusing topic - especially where it interacts with quantum physics - nobody understands that bit!

[devogue]

http://www.bbc.co.uk/news/science-environment-14289114

Physicists have confirmed the ultimate speed limit for the packets of light called photons - making time travel even less likely than thought.

The speed of light in vacuum is the Universe's ultimate speed limit, but experiments in recent years suggested that single photons might beat it.

If they could, theory allows for the prospect of time travel.

Now, a paper in Physical Review Letters shows that individual photons too are limited to the vacuum speed limit.

Bastards.

[charlou]

deja vu