Tuesday, February 03, 2009

Sudden Death of Entanglement

This is a very nice review of essentially the phenomenon of decoherence[1]. I finally had a chance to read through it. If nothing else, it has a wealth of references that I find highly valuable. What the review indicates is that the loss of quantum correlation (or decoherence) can occur a lot faster than "half-life decay".

What is more important, at least to me, is that this clearly shows why all the pseudoscience, mystical claims, and other crackpotteries that attempted to use QM and entanglement in particular to justify their claims completely and clearly show their ignorance of the subject matter. Many claims, such as this and this, only apply the physics that was probably gathered from popular science sources without understanding the physics, and without getting the whole picture. They only hear about "entanglement", without realizing what it is, how difficult it is to maintain, and how it can easily be destroyed. So they attempted to use it to justify something else without knowing all the "ground rules".

One would hope that these people would read a paper like this, but that's asking way too much, I'm sure. So if you encounter another of these crackpots trying to sell you on how we are all "entangled" with each other because QM says so, show him/her this paper.

Edit: a press release of this publication can be found here.


[1] Ting Yu and J.H. Eberly, Science v.323 p.598 (2009).

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