Guest Sunday, June 07, 2009 Well, so much for 'polite and to the point.' This may be a record even for a discussion board.
Kenneth Epstein Sunday, June 07, 2009Entanglement should not be regarded as spooky action at a distance. It should be regarded as a quantum-style conservation law, in this case conservation of spin angular momentum. I explained this in my article Entanglement Untangled, Physics Essays 19, 299 (2006).
It can occur on microscopic, mesoscopic, macroscopic, and megascopic scales. An example of mesoscopic entanglement is explained by Jorg Wrachtrup in the article Schrodingers Cat is Still Alive, Nature Physics 5, 248 (2009).
On the largest scale, there can be cosmic cats in the form of entangled galaxies in the expanding universe, which is in a quasiclassical state, i.e., a quantum state that allows nondemolition measurements on superpositions and entanglements, which are not disturbed by observation. The universe is the ideal place to observe megascopic quantum effects.
Max Tegmark showed that the brain is in a quasiclassical state. It is quite possible that the brain is a quantum analog computer whose normal modes are the normal modes of the universe, which has a fractal structure consistent with the Biblical statement that God created man in His own image, so that man can be regarded as a fractal of God, explaining how Einstein et al. get those resonance-like flashes of insight into the nature of things.
Kenneth J. Epstein Chicago, Illinois
Diogenes Sunday, June 07, 2009There is no "spooky action at a distance" and there is no "collapse" upon measurement. These are both quantum folklore.
pongosapiens Monday, June 08, 2009I remain fascinated that, as yet, there lacks the appreciation for the 'temporal elephant' in the room, only now be revealed at the quantum level. At some point, we must address 'time' as more than just perception or as an artifact of other, more fundamental factors. We may soon learn that the underlying explanation for "spooky" phenomena at the quantum scale, the reality of matter, as well as the apparent volume we call space may lie in that most troubling concept of Time.
The only important and logical part of the article, and the answer to the puzzle of entanglement.....
“For example, if the first one is measured and collapses into the up state, the second one will instantly collapse into the down state, even if it’s light-years away.”
“through a glass, darkly”
I thought we already had quantum computers that used entanglement. (?)
That mind-creasing "superposition" state lasts until an experimenter measures the ion's spin, at which point the ion instantly "collapses" to one direction or the other.
Or perhaps there is no objective collapse, and the world splits into two worlds, one in which the ion spins up and one in which the ion spins down.
Clueless layman question: How does one determine that a particle is in superposition since measuring it causes the “collapse” into one state or the other?