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View Full Version : Ep. 140: Entanglement



Fraser
2009-Jun-30, 03:00 AM
One of the most amazing aspects of quantum mechanics is quantum entanglement. This is the strange behavior where particles can become entangled, so they're somehow connected to one another no matter the distance between them. Interact with one particle and the other reacts instantly; if if they're separated by billions of light-years.http://feeds.feedburner.com/~r/astronomycast/~4/Lemxs4N3vXA

More... (http://feedproxy.google.com/~r/astronomycast/~3/Lemxs4N3vXA/)

Empyre
2009-Jul-12, 01:14 PM
After giving it some thought, I have come up with a scheme for instantaneous communication using entangled particles, but the whole thing depends on some assumptions that I am making that I fear may not be true. The assumptions are as follows:

When the wave forms of both particles are collapsed by measuring the spin of one of them, the particles remain entangled. You can flip the spin on one particle to send a bit of information, and the other particle flips too because they are still entangled, and the person on the other end can detect the flip thus receiving the information.

The previous paragraph is all assumptions I am making, and not statements of what I believe to be true. If that is all true, and only if that is all true, the limit of the rate of data transmission would be the slower of how fast you can flip the particle or how fast the other person can detect the flip.

So, the question is, is all that true? Would flipping the spin of one entangled particle cause the other particle to flip too? Would flipping the spin and detecting the flip be easy enough (with some technological advancement) to make this practical? If so, then latency-free transmission could be very handy even if both parties are on the Earth.

robross
2009-Jul-12, 01:57 PM
After giving it some thought, I have come up with a scheme for instantaneous communication using entangled particles, but the whole thing depends on some assumptions that I am making that I fear may not be true. The assumptions are as follows:

When the wave forms of both particles are collapsed by measuring the spin of one of them, the particles remain entangled. You can flip the spin on one particle to send a bit of information, and the other particle flips too because they are still entangled, and the person on the other end can detect the flip thus receiving the information.

The previous paragraph is all assumptions I am making, and not statements of what I believe to be true. If that is all true, and only if that is all true, the limit of the rate of data transmission would be the slower of how fast you can flip the particle or how fast the other person can detect the flip.

So, the question is, is all that true? Would flipping the spin of one entangled particle cause the other particle to flip too? Would flipping the spin and detecting the flip be easy enough (with some technological advancement) to make this practical? If so, then latency-free transmission could be very handy even if both parties are on the Earth.

No, the universe doesn't want you to do that so it won't let you. Basically, the uncertainty principle steps in and ruins everything. If you know the exact spin on the first particle, after changing it you would no longer know it exactly, thus the other particle doesn't know it exactly either, it's all probability waves.

There is no way we know of to transmit any information faster than light.

Rob