Warp - any scientific take on it?

[Krill]

Depends how you interpret what happens.

[Kuciwalker]

I cannot use quantum entanglement to send a message to you.

[Krill]

Well, if Wikipedia says it, then it must be true. Just looked it up.

[TCO]

Originally posted by Kuciwalker


Look more closely at the Lorentz transformation. If you can transmit image faster than light, you can send it back in time (by changing your frame of reference). Relativity breaks simultaneity.

So what. It still doesn't get a greater than infinite mass. "breaking simultanaity" sounds like fluff rather than a physical limit from an equation.

[Kuciwalker]

That's why I said earlier: relativity, causality, FTL - pick two.

If FTL transmission of information is possible, then you can do the following:

Get into a reference frame at event A where event B is in your future.

Send a message to event B faster than light.

The person at event B gets into a reference frame where A is in his future and sends A an FTL message.

A get the message he sent to B before he even sends it.

[TCO]

I don't think you can do it that fast.

[Kuciwalker]

If you can transmit information even 1 m/s faster than the speed of light it's possible. However, it requires fairly large energy expenditures if your transmission isn't much faster (to change your reference frame enough you have to accelerate to very high speeds).

[TCO]

No. I don't get you, how it happens in the first place. spell it out more.

[TCO]

I mean I have two different people 10 yards apart. They each have a synchronized clock. they are not moving. I use my superconducting wave collapser or whatever and then I transmit from one to the other instantly. How does that make the info come back to one before the other?

[Kuciwalker]

Okay. I'm at Event A (a point in spacetime), and I want to route a message to myself in the past, through Event B. While at rest [relative to B] it is in my future. That means that B's spacetime coordinates are within a cone directed "forward in time" with a slope related to c. I fire off a message to B at the speed of light or faster it will reach him. B then accelerates, so you have to do a Lorentz transformation since he's moving relative to A. However fast B moves (below c) A will still be outside B's light cone; however, if A gets close enough to the edge of the light cone the FTL transmission could reach it. So he accelerates to that speed, sends the message FTL to A, and I receive it, at or before the time I sent it.

[Kuciwalker]

The key point is that the person at B is moving.

[TCO]

I still don't get it. I send the stuff simultaneously. How can it go back in time. say it simple. Without all the cones or the devices of einstein diagrams and such.

[TCO]

Originally posted by TCO
I mean I have two different people 10 yards apart. They each have a synchronized clock. they are not moving. I use my superconducting wave collapser or whatever and then I transmit from one to the other instantly. How does that make the info come back to one before the other?

THIS.

[Kuciwalker]

I can't do that without doing the algebra, and I don't feel like that :P



Information transferred at the speed of light follows the edges of that cone.

Let's assume information can be transmitted instantaneously. This actually works for any speed > c, but it's the simplest way to illustrate things. Instantaneous transmission follows the horizontal axis.

Now, let's say when we're at rest relative to each other, A and B lie on the same horizontal axis. So I send a message instantaneously to B. B then accelerates, so all points not on the edge of the cone are subject to the Lorentz transformation (which maps the edges of the cone to themselves). This makes A look like it's farther ahead in time (though it cannot bring A from section III to section I). B can then send the message instantaneously to A's past.

[TCO]

You should be able to explain it. If it is physical. In physical terms. A rocket ship not going faster than light because it's mass increases to infinity, in the limit as it gets to speed of light is physical.