Faster than light shenanigans

[JamesNBarnes]

Just want clarification on a point of interest for me.

 

Is it possible for the soul to travel faster than light?

 

I kid, but thats not a million miles from my intended question.

 

Ive read that two "objects" can exist in a "quantum entangled" state, in the same book it was theorised that this could provide faster than light communication.

 

In a nutshell, if one of our quantum maguffins where on earth, and one was 30million light years away, a change to our earthbound maguffin results in an instant change to our distant maguffin, from which the state of the earth bound maguffin can be extrapolated. Voila faster than light internet!

 

However, i also remember reading that information cannot travel faster than light, with, if i remember correctly, the idea of an incompressible rod, stretching a huge distance, with poking of one end of the rod, being transmitted instantly to the other. This was refuted.

 

So is faster than light communication possible?

 

That brings me onto my next question, im neither a mathematician or a physicist, so my understanding of dimensions is limited, with this in mind, how do we measure "speed"?

 

 

Its problematic, because we need a reference point, so say for example, we poked a hole in "space" in one place, our starting point, then poked another hole in space at our intended destination, then using my cosmic sewing kit we stitched these holes together. In my limited understanding, i suppose this could be called a worm hole.

 

Essentially we have an extradimensional shortcut from point a to point b.

 

An observer at point A would see our craft entering the the wormhole at point a, and exiting at point b. To him it would appear that the craft had reached there in less time than it would have taken light to make the journey through normal space.

 

So whereas the people aboard the craft may have seemed to travel a short distance, lets say an arbitrarily short distance from a through the wormhole to b, at a speed significantly less than light.

 

So we have 2 different observers, with two different speeds.

 

From my basic familiarity with relativity, i know enough to suspect that its all well explained, but could any one clarify?

 

Thanks

[ajb]

It is well established that you cannot send information via quantum entanglement.

 

In essence such systems have exactly the right amount of noise to make them useless for faster than light communications.

[JamesNBarnes]

Oh i see ok, ill see what i can dig up in that area.

 

Any info on the incompressible rod?

[ajb]

Any info on the incompressible rod?

 

As in there is no such thing in special relativity?

 

If so, any book on special relativity will say something.

[swansont]

Ive read that two "objects" can exist in a "quantum entangled" state, in the same book it was theorised that this could provide faster than light communication.

 

In a nutshell, if one of our quantum maguffins where on earth, and one was 30million light years away, a change to our earthbound maguffin results in an instant change to our distant maguffin, from which the state of the earth bound maguffin can be extrapolated. Voila faster than light internet!

 

Don't trust that book.

 

When you measure the state here you will instantly know the state 30 million LY away. But you do not know it beforehand, you have not communicated any information in doing so, and once you make the measurement, the entanglement is broken. Changing the state afterwards does nothing to the distant particle.

[JamesNBarnes]

Ah i see, i didnt know that measuring would have broken the entanglement.

 

Also, to be fair to the book, it was probably me who was in error. I read it some while ago, and my memory is shaky at the best of times. It may have been a case of reading about entanglement and then extrapolating (wrongly) that this might be possible.

 

Thanks for filling me in though.