Time Travel Impossible

[Phenom]

Please refer to title, thank you.

 

[Knyro]

SHOCKING NEWS!: LIGHT DOES NOT TRAVEL FASTER THAN LIGHT!

ORLY?

Seriously though I'm still not sold on this article. All they've really proven is that light speed travel is not possible (wait a minute, I thought we knew this already? :wtf. I don't think that necessarily means that time travel is impossible. What about quantum entanglement? What about time dilation?

Maybe they've disproven one way of time travel i.e. going faster and faster until who knows what happens when you pass the speed of light. That still leaves the question of time travel via warping space/time. Wormholes (along with superluminal travel) are very valid solutions to some of Einstein's equations in the area of General Relativity which allow for time travel . In order to work though they'd rely on dark energy, research into which looks very promising at the moment. So time travel this way does not go against any known physics, but we're still a ways off.

I'd say we'll only know for sure if time travel is possible or not when someone manages to unify quantum mechanics and general relativity. This article is terribly misleading IMO. Popsci strikes again.

 

[Elimentals]

Time travel via faster than light is know to have its problems, and getting to that speed is not the issue its passing it as we know that time stands still at the speed of light.

 

[Knyro]

Time travel via faster than light is know to have its problems, and getting to that speed is not the issue its passing it as we know that time stands still at the speed of light.

Actually that is a big issue, in fact it's the whole issue. You need an infinite amount of energy to accelerate an object TO the speed of light, never mind passing it. That's why time travel this way looks very unlikely.

 

[Archer]

No. You can make time pass slower (and hence relatively speaking also speed it up) but you cant go back according to our current understanding of the universe.

 

[Rosaudio]

But Hawkings said it was possible

 

[Archer]

But Hawkings said it was possible

Travelling forward in time yes. iirc he never once said travelling back in time was possible

 

[Rosaudio]

Travelling forward in time yes. iirc he never once said travelling back in time was possible

Yeah I know. Aren't they talking about any time travel though?

 

[Archer]

Yeah I know. Aren't they talking about any time travel though?

I would assume not since making time go faster/slower is a very well documented fact. This was demonstrated by two atomic clocks reporting different times because they were at different altitudes, and hence experienced different gravitational fields. Satellites in fact have to compensate for this so that they keep to earth time, something like 40ms per day

 

[OomD]

The way I see it, it is obvious that photons cannot travel faster than the speed of light. Well, to me at least but I've been known to be wrong before

Anyway, considering speed itself; the speed of light (or 'c') is not the fastest speed, and this is easy to prove. In order for an object to move from point A to point B at infinite speed it needs to appear at B the same time it disappeared at A. But, it needs to have moved between A and B, and this will take time. No matter how short this time period is, there is always a shorter period while never reaching a time of zero. It is like halving a number, no matter how many times you have halved it you can half it again, without ever getting to 0. Now considering c, if an object travels between point A and B at a rate of c it will take X time (depending on the distance between A and B), and that time can be halved.

So, the speed of light is not the ultimate speed, it is merely the highest speed attainable by a photon. I guess what I am saying is that it is not light that determines the maximum speed, there is something else that determines the maximum speed. Light just happens to be the fastest one we know of.

Perhaps there is something else out there that can actually travel between A and B in a shorter time, but for now we don't know about it. For now.

 

[Elimentals]

The way I see it, it is obvious that photons cannot travel faster than the speed of light. Well, to me at least but I've been known to be wrong before

Anyway, considering speed itself; the speed of light (or 'c') is not the fastest speed, and this is easy to prove. In order for an object to move from point A to point B at infinite speed it needs to appear at B the same time it disappeared at A. But, it needs to have moved between A and B, and this will take time. No matter how short this time period is, there is always a shorter period while never reaching a time of zero. It is like halving a number, no matter how many times you have halved it you can half it again, without ever getting to 0. Now considering c, if an object travels between point A and B at a rate of c it will take X time (depending on the distance between A and B), and that time can be halved.

So, the speed of light is not the ultimate speed, it is merely the highest speed attainable by a photon. I guess what I am saying is that it is not light that determines the maximum speed, there is something else that determines the maximum speed. Light just happens to be the fastest one we know of.

Perhaps there is something else out there that can actually travel between A and B in a shorter time, but for now we don't know about it. For now.

I understand what you trying to say only one small problem, time is relative. See Time dilation

According to the theory of relativity, time stands still at the speed of light or the maximim speed. Example for you it will seem that the photon leaving the sun took 8 minutes to get here but for the photon itself it happened in an instant. That is why I say you can not pass the barrier of lightspeed as time stands still and you will not be able to react as you need time to do so.

Time travel approached from quantum physics is a total different matter as we know particles jump forwards and backwards all the time, and can also be at 2 places at once so in theory covers your point A to B argument.

 

[OomD]

I understand what you trying to say only one small problem, time is relative. See Time dilation

According to the theory of relativity, time stands still at the speed of light or the maximim speed. Example for you it will seem that the photon leaving the sun took 8 minutes to get here but for the photon itself it happened in an instant. That is why I say you can not pass the barrier of lightspeed as time stands still and you will not be able to react as you need time to do so.

Yes, yes. Some nice food for thought here, thx.

...

and can also be at 2 places at once so in theory covers your point A to B argument.

Indeed, I have read up on this before. But then again, at the quantum level all the rules change, agreed. I was, however, referring to photons specifically and the way light propogates, which is still way higher than quantum level. But I see your point, and agree too.

 

[zippy]

I understand what you trying to say only one small problem, time is relative. See Time dilation

According to the theory of relativity, time stands still at the speed of light or the maximim speed. Example for you it will seem that the photon leaving the sun took 8 minutes to get here but for the photon itself it happened in an instant. That is why I say you can not pass the barrier of lightspeed as time stands still and you will not be able to react as you need time to do so.

Time travel approached from quantum physics is a total different matter as we know particles jump forwards and backwards all the time, and can also be at 2 places at once so in theory covers your point A to B argument.

I don't think we "know" that particles jump forwards and backwards all the time. They seem to be disappear and reappear randomly. Knowing is different to having theory that particles can moving backwards and forwards. These new finding make this even less likely. We still don't know the full nature of matter and we are seeing the effect of a particle as it switches between a phase we understand and can observe and one which we don't understand and so far are unable to observe.

 

[mercurial]

Can't be done? Haha. Watch Through The Wormhole. I think it was season 2 episode 6 or 7. They have seen that the properties of light is not as constant and consistent as we thought. We may be able to travel faster than light. Time travel is another story, though.

 

[w1z4rd]

Time travel into the future is very possible with time dilation, its a proven phenomena. Its one of the reason they have to keep adjusting clocks on satellites.

 

[mercurial]

SHOCKING NEWS!: LIGHT DOES NOT TRAVEL FASTER THAN LIGHT!

ORLY?

Seriously though I'm still not sold on this article. All they've really proven is that light speed travel is not possible (wait a minute, I thought we knew this already? :wtf. I don't think that necessarily means that time travel is impossible. What about quantum entanglement? What about time dilation?

Maybe they've disproven one way of time travel i.e. going faster and faster until who knows what happens when you pass the speed of light. That still leaves the question of time travel via warping space/time. Wormholes (along with superluminal travel) are very valid solutions to some of Einsteins equations in the area of General Relativity which allow for time travel . In order to work though they'd rely on dark energy, research into which looks very promising at the moment. So time travel this way does not go against any known physics, but we're still a ways off.

I'd say we'll only know for sure if time travel is possible or not when someone manages to unify quantum mechanics and general relativity. This article is terribly misleading IMO. Popsci strikes again.

100%

 

[Elimentals]

I don't think we "know" that particles jump forwards and backwards all the time. They seem to be disappear and reappear randomly. Knowing is different to having theory that particles can moving backwards and forwards. These new finding make this even less likely. We still don't know the full nature of matter and we are seeing the effect of a particle as it switches between a phase we understand and can observe and one which we don't understand and so far are unable to observe.

I dont think you truly understand quantum maniacs or what it entails: IE a wave is a particle is a wave(Wave–particle duality) depending on you observation. It is in this state of observation where we theorize that it exist both in the future as well as the present, also can be at different places at the same time.

Then again I am sure many people will and did go nuts trying to warp their brains around the quantum world.

If you interested check out http://www.colorado.edu/philosophy/vstenger/Briefs/QuantumTimeTravel.html

 

[syntax]

We probably never will be able to go back in time, but I can "time Travel". All I need is to go really really fast or be near something really really dense and have you far away from me

 

[Ninja'd]

What about mental time travel?

 

[w1z4rd]

What about mental time travel?

Thats crazy!

Haha.. I kill me.