RE: First collisions at the LHC with unprecedented Energy! (Ask a particle physisicist)
September 2, 2015 at 4:39 am
(This post was last modified: September 2, 2015 at 4:40 am by Alex K.)
(September 1, 2015 at 4:53 pm)Cthulhu Dreaming Wrote: Here's something that kept me awake the other night.
You are no doubt familiar with some of the various experiments with quantum entanglement. The experiments and their results are strange enough to be sure, but my question isn't really about that.
How are individual entangled (or non-entangled, for that matter) particles observed? (Think back to the 1998 Caltech experiment where an individual photon was "teleported" about a meter. What means is used to make the observations?
Often , a particular property of the particle is measured. For example, the polarization of a photon. The photon itself can be measured using a photo multiplier, and the polarization is decided by putting a polarizing surface or something in front of the photomultipliers. E.g. the decay of spin 0 positronium into two photons can be assumed to produce a quantum superposition of two photons with entangled opposite polarizations going off in opposite directions. One then catches them as far apart as possible with detectors set up on opposite sides of the source. Does that answer the question a bit?
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
