system
Given the following post, respond as if you're commenting on Reddit:
human
Two questions about black holes (quantum entanglement and anti-matter)

Question 1:

So if we have two entangled particles, could we send one into a black hole and receive any sort of information from it through the other?  Or would the particle that falls in, because it can't be observed/measured anymore due to the fact that past the event horizon (no EMR can escape), basically make the system inert?  Or is there some other principle I'm not getting?

I can't seem to figure this out, because, on the one hand, I have read that irrespective of distance, an effect on one particle immediately affects the other (but how can this be if NOTHING goes faster than the speed of light?  =_=).  But I also have been told that observation is critical in this regard (i.e. Schrödinger's cat).  Can anyone please explain this to me?  


Question 2

So this one probably sounds a little "Star Trekky," but lets just say we have a supernova remnant who's mass is just above the point at which neutron degeneracy pressure (and quark degeneracy pressure, if it really exists) is unable to keep it from collapsing further.  After it falls within its Schwartzchild Radius, thus becoming a black hole, does it IMMEDIATELY collapse into a singularity, thus being infinitely dense, or does that take a bit of time?  <===Important for my actual question.  

Either way, lets say we are able to not only create, but stabilize a fairly large amount of antimatter.  If we were to send this antimatter into the black hole, uncontained (so as to not touch any matter that constitutes some sort of containment device when it encounters the black hole's tidal/spaghettification forces [also assuming that there is no matter accreting for the antimatter to come into contact with), would the antimatter annihilate with the matter at the center of the black hole, and what would happen?

If the matter and antimatter annihilate, and enough mass is lost, would it "collapse" the black hole?  If the matter is contained within a singularity (thus, being infinitely dense), does the Schwartzchild Radius become unquantifiable unless every single particle with mass is annihilated?
gpt
So, for your first question: as people have mentioned, quantum entanglement does not transfer information- and is probably not what you might think it is. Science writers, when covering this concept, have greatly oversold what the entanglement means. The classic example is a particle that decays into two particles. Say the parent particle had no angular momentum (zero spin, in the quantum world). By conservation of momentum we know the two child particles must have a total of zero angular momentum, so they must either both have no angular momentum (boring for this discussion) or opposite angular momentum (spin up and spin down in quantum mechanics). Quantum entanglement simply is a discussion of the fact that if we know the angular momentum of the first particle, we then know the angular momentum of the second. The cool part of quantum entanglement is that until one is measured, neither particle has "chosen" yet and until one is measured, either particle could be measured to have spin up or spin down (aka- it isn't just that we don't know which one is which until we measured, but that it hasn't happened until we measured). That's really it. It is cool, but the science writers who claim quantum entanglement will allow new types of measuring tools are doing a great disservice. 

Now for the second question. First, matter does not exist inside of a black hole. A black hole is a true singularity, it is mass, but without matter. Any matter that falls into a black hole loses all of it's "matter characteristics." Now, conservation laws still remain- mass, charge, angular momentum, energy, etc are still conserved, but there is no "conservation of matter" only a conservation of mass law. 

However, even if a black hole still had matter in it which could react with anti-matter, it wouldn't matter. We think of mass of being what causes gravity- but it is really a different quantity called the stress-energy tensor. For almost all "day to day" activities, the stress-energy tensor is analogous to mass, but in your case- it really isn't. The stress-energy tensor, as the name implies, is also dependent on energy. And while normally you never notice- in a large matter/anti-matter reaction, you'd have to take it into account. In fact, when matter and anti-matter react, the value of the stress-energy tensor is the same before and after the reaction. Normally, the energy spreads out, at the speed of light, so that "mass" is spread out really quickly as well, and thus you don't notice the effects. But in a black hole, that energy cannot escape, so all of that "mass" is retained. 

The confusion comes from people mis-teaching the interpretation of E = mc^2 . This is a long discussion, but in summary, E=mc^2 doesn't mean "mass can be converted into energy" but that "energy adds to the apparent mass of the object." You probably first heard of E = mc^2 when talking about nuclear reactions, say a nuclear bomb. And it is said "some of the mass is converted into energy, and then boom!" But really, it is better to say "in a nuclear reaction, mass is carried away from the bomb by the energy." So, for instance, put a nuclear bomb inside a strong, mirrored box, put it on a scale, and blow it up. The scale will read the same before and after the explosion. Then, open up that box, allow the heat and light to escape- and at that point you will notice the scale go down.