Response to Relativity discussion
Relativity is clearly the most bizarre thing that we have studied so far. Applying it to things that we thought that we understood reveals a whole new set of questions about them. For lack of a given, more precise topic, then, these questions are what I will write about here; I'll try to understand the application of relativity and the things that we have discussed to other aspects of astronomy and physics.
To start with, a question about light. This is a question closely linked to one of the original 5 that I gave at the start of the year: Given the nature of light, how does one explain the Doppler Effect, the changing of the frequency of light? Because light is moving at the speed of light in space, it can't be moving at all in time (given that velocity is distance per unit time, I don't see how this works exactly, but it is the accepted theory as I understand it, so I'll accept it as true for now). If something experiences no time, it cannot change; or, at least, that is what I would think. Frequency in light is the measure of a repeating pattern contained in a stream of light. If the light can't change, and it is moving at a constant velocity relative to all reference points, that pattern should not, I would think, change at all from its transmission from a star to its reception here on Earth. But it clearly, and verifiably, does change, so either one of my assumptions here is incorrect or light frequency does not follow the same rules as light. I could certainly see this being the case; I just don't know why it would be so.
Another question that wasn't quite answered was, Why do black holes stay as black holes? They must have stopped 'burning' as stars; if they were still fusing and producing energy, their mass would be decreasing while their force outwards increased. Eventually, the mass would decrease to the point where the formation no longer qualified as a black hole. So black holes must no longer be producing energy through fusion. But they are fusing, as we discussed, so the fusion must not release energy, or the force inwards of gravity, even the force remaining after subtracting the outward force of the explosions, must be crushing the stuff in a black hole together at a rate that exceeds the rate of destruction of mass.
A third question: If crushing down objects until their constituent subatomic particles are adjacent creates enough density to form a black hole, would these particles themselves not be dense enough to form black holes, albeit very small ones (if such a term can even apply to such a distortion of space/time)? It would seem not; I don't think that I am, at present, surrounded by (and made up of) tiny points that don't exist and from which nothing can escape. Maybe this is one of those points where relativity no longer applies, where quantum mechanics takes over; maybe it is a point for which we would need to understand superstring theory. In either case, it is a question for later in the year, after we have studied at least one of those two things.
It would seem that relativity, or at least my understanding of it and its limitations, is not sufficient to answer these questions. This is no great suprise; if they were easy, I wouldn't have bothered to ask them. This is where science really, in my opinion, becomes interesting; if there isn't an unanswered question out there for someone to try to solve, what's the point? Fortunately, due to the nature of science as we know it today, there should never be a shortage of fun stuff to figure out in science.