I'm a mathematician. To leave me a note, just edit this page:
MVH - If you have time, please help a more novice student understand your notes on quantum entaglement. Specifically:
1. Can we change spin?
2. If we change spin on one particle, does the spin "instantly" change on the other, even if it is, say 1 million light years away?
3. Assuming that the distant particle would change spin instantly, and one monitoring the spin could detect and determine the change in less than 1 million years, would/could that not be communication faster than light? (Considering that changes in binary state are the basis of all digital electronic communications)
Thank you, if you have the time, for your help to untangle these issues. I will check this page from time to time for your responses.
- Roger, I've been away from wikipedia for a number of years, so this is a really slow reply. Concerning question 2, the answer is no. What you are describing is what Einstein would have called: spooky action at a distance. The issue is subtle, what the experiments showed is not a spooky "action" at a distance, but rather, a spooky "correlation" at a distance.
- The answers are "no". We do not directly change the spin on entangled particles, but rather we observe the spin they have. Once one particle is observed (and it assumes a particular spin), the other particle it is entangled with instantly assumes the opposite spin. So no information on our part is communicated to or between the particles.
- Personally, I theorize that the particles are part of a multi-dimensional system (perhaps within the other dimensions postulated by string theory) where the particle spins are hidden until an interaction with other matter-energy (such as an observer) causes the hidden spins to interact with matter-energy outside the entangled pair, and that prior to that outside interaction the particles interact only through the tiny Planck scale dimensions. But I don't claim to be an expert, and this theory is probably not testable. — Loadmaster (talk) 22:51, 6 March 2014 (UTC)