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Beginner's Guide to Quantum Entanglement

Posted by Zonk on from the in-case-you-need-to-make-your-own-universe dept.

No Fortune writes "Einstein called it 'Spooky action at a distance.' This article describes, in scientific layman's terms, how spooky action is created." From the article: "Normally the photons exit the crystal such that one is aligned in a horizontally (H) polarized light cone, the other aligned vertically (V). By adjusting the experiment, the horizontal and vertical light cones can be made to overlap. Even though the polarization of the individual photons is unknown, the nature of quantum mechanics demands they differ."

1 of 186 comments (clear)

  1. Weird thought by achurch · · Score: 4, Interesting
    In the midst of serious sleep deprivation, the following weird analogy for quantum entanglement came to mind. Maybe some of the physics folks here can tell me why it's wrong:

    Suppose you take a coin and spin it on a frictionless surface in a vacuum, so that it's perfectly balanced and doesn't wobble. In theory, it will keep on spinning at the same rate forever.

    Now suppose you take a second coin, identical in all respects to the first, and start both coins spinning at the same time--but with one of them 90 degrees out of phase compared to the other, so when one is "horizontal" when viewed from above, the other is "vertical".

    Finally, suppose you have a way to move the coins without affecting their rotation. Move one of the coins as far away as you like from the other.

    Reach out a finger and stop one of the coins. Suppose that at the instant you stopped it, the coin was horizontal. You now know that, at that particular instant, the second coin was vertical--not because the coins somehow "communicated" with each other, but simply because they both followed the same laws of physics up until you interfered.

    Granted, I'm oversimplifying tremendously, but is this a semi-reasonable explanation of why quantum entanglement has nothing to do with instantaneous communication, or do I just need to get to sleep?