
You can’t get entangled without a wormhole (2013) - saurabh
http://newsoffice.mit.edu/2013/you-cant-get-entangled-without-a-wormhole-1205
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dools
When I watched the Leonard Susskind lectures on quantum entanglements he said
the whole "communicating faster than light" thing is a bit misleading. The
analogy he gives if imagine you have two coins and you ask someone to turn
them over so one is heads and the other tails then you give them to 2 people
without them knowing which is which, then they go to opposite ends of the
universe, and they look at their coins, they instantly know the state of the
other coin purely by deduction.

~~~
ninkendo
From what I've read, the rub is that you don't know which side of the coin the
current one is until you observe it, and only at the exact time of observation
does the other coin assume the other state.

Apparently, the point at which you observe the one coin is called the collapse
of the wave function, and we have ways of directly measuring that the collapse
doesn't happen until one of the particles is observed. (But it's never been
too clear to me how that's possible... if observing a particle collapses the
wave function, how do we observe _when_ the collapse happens, without first
observing the particle?)

~~~
Jach
The problem with the 'collapse' point of view is that it's easy to say "and
thus only the observation we saw actually exists". But that's an extra
postulate beyond asserting the wavefunction describes all of reality. By just
saying the wavefunction describes all of reality, you wind up with Many-
worlds: [http://en.wikipedia.org/wiki/Many-
worlds_interpretation](http://en.wikipedia.org/wiki/Many-
worlds_interpretation) So the coins/paper analogies do make sense, except that
there's not a single outcome: there are two possible outcomes, both realized,
but each version of you interacting ("observing" is a loaded term) with the
system to the point of decoherence
([http://en.wikipedia.org/wiki/Quantum_decoherence](http://en.wikipedia.org/wiki/Quantum_decoherence))
only ever get to see one of the worlds, which is the one you find yourself in.
This isn't that mysterious given that your brain and everything else in your
body are made of the same fundamental particles as everything else.

You highlighted a problem with quantum computers and other things: how to make
sure a system is in a quantum state without directly measuring it. It's hard
to fight decoherence.

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mef51
The paper:
[http://arxiv.org/pdf/1307.6850v3.pdf](http://arxiv.org/pdf/1307.6850v3.pdf)

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pistle
Stop stop stop saying "communicating at a distance." They may be formed or
placed into an "entangled" state, but they aren't communicating through any
physical wormhole.

It's waves all the way down. And string theory? Someone pass the arxiv...

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orbifold
This is pointed out in the research article, but the overall idea that matter-
antimatter pairs created in the vacuum are connected by a wormhole is due to
Wheeler. The twist here is that the result is obtained by applying ADS-CFT
duality first, so the calculation is done in a 5 dimensional gravitational
theory. A more accurate statement would be that under ADS-CFT an entangled
particle state in 4 dimensions probably can be modelled as a wormhole in the
gravity dual, which is not entirely surprising.

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sideshowb
Like everyone else here says, entanglement doesn't give rise to FTL
communication. So can someone explain to me how this paper even exists / has
anything to explain via wormholes?

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atilev
if this is validated it might be the single most important piece of proof in
our lives we just don't know it yet...

