Understanding the Effects of Entanglement in Radioactive Decay

[Trollfaz]

Lets say a radioactive atom decayed into an alpha particle and a daughter nucleus. The two particles are entangled. If you measure, the alpha particle, you will collapse the wavefunction of the daughter nucleus. Other than collapsing wavefunction, does have any effect on the daughter nucleus?

 

[jfizzix]

In short, nope.

In slightly longer form:
The only other interaction besides collapsing wavefunction would be due to electromagnetic radiation emanating from the alpha particle and measurement device due to whatever interaction was involved in measurement. This radiation (if any) rapidly decreases intensity with distance, as it propagates at the speed of light. Once that radiation finally reaches the daughter nucleus, the probability if an appreciable change in the quantum state (say, by absorbing a photon) is negligibly low.

Guessing from the thread title, I can say in a nutshell, that (our current models show) there is no way of telling by measuring a single particle if it happens to be half of an entangled pair. You would have to measure the other half of the pair to see the entanglement, which throws a wrench into FTL communication via entanglement.

 

[Nugatory]

If you measure, the alpha particle, you will collapse the wavefunction of the daughter nucleus.

You will collapse the wave function of the entire quantum system which includes the alpha particle and the daughter nucleus. That's a very different thing.

 

[Nugatory]

You would have to measure the other half of the pair to see the entanglement,

And even that's not good enough... You would have to repeat this measurements multiple times on multiple pairs, and find a stronger correlation than just random chance is likely to produce.