It is no good getting furious if you get stuck. What I do is keep thinking about the problem but work on something else. Sometimes it is years before I see the way forward. In the case of information loss and black holes, it was 29 years. ↗
Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out. ↗
The radiation left over from the Big Bang is the same as that in your microwave oven but very much less powerful. It would heat your pizza only to minus 271.3*C - not much good for defrosting the pizza, let alone cooking it. ↗
I would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy, without pollution or global warming. ↗