Speed of Light

Originally posted by torchmoon
I'm female not a guy (sounds of groans and oh that explains it heard), and kind of wish i never asked. I'm not big on physics as you all now know! I don't understand a word of what you all have said. It was supposed to be a fun question based on pub talk with my mates, sorry guys 😳

No sorries needed bu your part. I'm the one who's sorry. 😳

Originally posted by agryson
Well, technically, even an object of normal mass, if by some means gets from one point in space to another faster than a photon could, it's travelled faster than the speed of light. there's many theoretical methods of doing this, so for the sake of argument, if we did it by a wormhole, or say warping spacetime (the local mass stays stationary, but the space ...[text shortened]... gives hope to 'getting around' the Universal speed limit for us ordinary lumps of mass.

But wormhole travel isn't really a way of getting to speeds bigger than the speed of light. I think you know that but we must have some care not to misslead others.

http://arxiv.org/PS_cache/gr-qc/pdf/0508/0508082v1.pdf

Just found this article on arxiv. I think it's a good introdutory one on tachyons.

Edit: On second thought maybe it is a little too dense. Sorry 😳

Edit2: Some more articles on it:

http://arxiv.org/PS_cache/astro-ph/pdf/0407/0407603v1.pdf
http://arxiv.org/PS_cache/hep-ex/pdf/0305/0305008v1.pdf
http://arxiv.org/PS_cache/physics/pdf/0303/0303004v1.pdf
http://arxiv.org/PS_cache/astro-ph/pdf/9505/9505117v1.pdf

Of course I haven't read all of those articles, just the abstracts, but they seem relevant for our discussion.

Originally posted by adam warlock
But wormhole travel isn't really a way of getting to speeds bigger than the speed of light. I think you know that but we must have some care not to misslead others.

There is a subtlety that I didn't mention, so the answer to 'can you travel faster than the speed of light with a wormhole? is...Yes and no, it depends on the frame of reference. No, from your point of reference you are travelling at a pretty slow speed comparitively, but to an outside observer, Yes, you got from point A to point B in an amount of time T, which with wormholes can result in a velocity greater than light.
You're right that it's cheating, but from what I've seen of the theories, that's the only way to do it, whatever your method.
The other problem with wormholes is that your image wouldn't move between point, it would dissappear, and then reappear.
I was only trying to demonstrate that there are many ways of achieving the effect, but there are subtleties I failed to mention. Hope that's been cleared up...

Originally posted by agryson
There is a subtlety that I didn't mention, so the answer to 'can you travel faster than the speed of light with a wormhole? is...Yes and no, it depends on the frame of reference. No, from your point of reference you are travelling at a pretty slow speed comparitively, but to an outside observer, Yes, you got from point A to point B in an amount of time T, wh ...[text shortened]... the effect, but there are subtleties I failed to mention. Hope that's been cleared up...

Does light travel through worm holes too?

Originally posted by FabianFnas
Does light travel through worm holes too?

Yes, in fact it's MUCH easier for a photon to get through one than anything larger. But it would not defy relativity because when you view it from its inertial frame, it's not breaching the speed limit. Sending a stream of photons through a wormhole would give them the appearance of faster than c speed, just like the spaceship. Classical physics would say it had gone faster, but there are experiments you could do to eliminate the illusion.

Have two wormhole on either side of a prism. send photons through. they would come out the other side without refraction, because they did not pass through the prism. In this way, as light travels in straight lines, even if you didn't know about the wormholes, you could infer their existence.

Originally posted by agryson
Yes, in fact it's MUCH easier for a photon to get through one than anything larger. But it would not defy relativity because when you view it from its inertial frame, it's not breaching the speed limit. Sending a stream of photons through a wormhole would give them the appearance of faster than c speed, just like the spaceship. Classical physics would say it ...[text shortened]... straight lines, even if you didn't know about the wormholes, you could infer their existence.

Interesting!

How long is a worm hole? I mean, suppose I go from here to (say) 10 light years away, is then the worm hole 10 LY long from the entrence to the exit of the hole? Or is the entrance next to the exit so you acutally have no distance at all, and therefore go with a normal 'everyday' velocity all the way?

Originally posted by FabianFnas
Interesting!

How long is a worm hole? I mean, suppose I go from here to (say) 10 light years away, is then the worm hole 10 LY long from the entrence to the exit of the hole? Or is the entrance next to the exit so you acutally have no distance at all, and therefore go with a normal 'everyday' velocity all the way?

As far as I'm aware, though you may need to look this up, they are fairly spread in their sizes, so this one could cover 10 ly in 10 centimetres, while that one over there might take a few kilometres. In any case, it's much shorter.

Originally posted by agryson
As far as I'm aware, though you may need to look this up, they are fairly spread in their sizes, so this one could cover 10 ly in 10 centimetres, while that one over there might take a few kilometres. In any case, it's much shorter.

And where is the tunnel between its entrence and its exit? In som other macro dimension? And what happens if you stop your rocket (or travelling device) inside the tunnel? And what do you find if you probe the tunnel walls? Can you drill your way through the tunnel wall and find yourself som other place?

No, I understand that there isn't any answers for these kind of questions, I just ask for your opinion, you seem to have given it a lot of thoughts already.

Originally posted by agryson
There is a subtlety that I didn't mention, so the answer to 'can you travel faster than the speed of light with a wormhole? is...Yes and no, it depends on the frame of reference. No, from your point of reference you are travelling at a pretty slow speed comparitively, but to an outside observer, Yes, you got from point A to point B in an amount of time T, wh ...[text shortened]... the effect, but there are subtleties I failed to mention. Hope that's been cleared up...

Yep. I figured out you knew what you were talking about but I couldn't help myself. 🙂

Originally posted by FabianFnas
And where is the tunnel between its entrence and its exit? In som other macro dimension? And what happens if you stop your rocket (or travelling device) inside the tunnel? And what do you find if you probe the tunnel walls? Can you drill your way through the tunnel wall and find yourself som other place?

No, I understand that there isn't any answers fo ...[text shortened]... of questions, I just ask for your opinion, you seem to have given it a lot of thoughts already.

http://www.math.ucr.edu/home/baez/physics/

This is a good site with a lotta questions on physics well explained. Check it out. 🙂