It's currently trendy to talk about the multiverse, the alleged existence of many individual \"universes\". a. One version of it involves innite universes, all adjacent to each other in space, with some expanding and some contracting, and with no explicit boundaries between them. In this theory, they've existed for all time, so it avoids the problem of what happened before the Big Bang. Explain how a simple observation that anyone can make debunks this theory. b. Another multiverse proposal postulates parallel universes, which don't interact with each other in any way. Explain why this is a pointless idea and so not worth considering beyond this homework problem. c. I just invented my own parallel-universe theory for the sake of this homework problem. It comprises additional universes of the same type of particles as ours, which interact gravitationally with ours, but which have their own electromagnetic, strong, and weak forces that don 't interact with ours. As a result, there'd be parallel galaxies of stars and planets co-existing with ours, whose gravity we'd feel, so they'd be detectable, but whose light wouldn't and which we'd pass right through, due to the non-interacting electromagnetic forces of the different parallel universes. a. How many such universes would be required by known data? b. Describe a discrepancy between this theory and current observations that would need to be somehow explained for this theory to avoid being falsified. c. Finally, we actually already have a name for the matter of these universes; what is it