Quote:
Originally Posted by Sparrow
The Wikipedia artice says:
"When particles decay into other particles, these decays must obey the various conservation laws. As a result, pairs of particles can be generated that are required to be in certain quantum states."
If the entanglement breaks when one particle traverses an event horizon - wouldn't that mean one particle can be resolved while the other isn't? |
At the time of their creation, the particle duo must, of course, observe the conservation laws. At that time, to borrow from the example Wikipedia uses, you have two particles (= waveform functions) that posess an observable (which could be described as the quantum mechanical representation of a physical property), continuing to borrow from the example, let's consider spin. At this time, you cannot make a statement about the ((eigen-)value of the observable) spin of either particle. Now, if you measure just one of the particles, that particle's waveform will collapse into one of the states it's allowed to, let's say it is a particle with two spin eigenvalues (up and down), and it collapses into up. So, in short, we measured one particle to have a spin oriented up. Now, because these particles, at their creation, had to obey conservation laws, the second particle's wave function will, simultaneously with the first one's, collapse into a corresponding wavefunction in a way that all relevant laws are honored. Let's say the particles were created from a situation in which the total spin was zero, then you could, without making a second measurement, state that because you measured the first particle's spin to be up, the second particle's spin must then be down.
Edit to answer the second question as well: I'm actually not too sure about what would happen to the particles if the entanglement breaks. I think that, on one hand, the conservation laws still apply, but then you couldn't break the entanglement without collapsing both wavefunctions. If we apply this to the case of pushing one particle over the event horizon of a black hole, that would, I believe, constitute an information transfer, which is prohibited. The caveat is that I didn't think about what constitutes information, which is a little more complicated in these cases and is, I suspect, extremely relevant in this case.