– That’s absolutely right, because what Boltzmann taught was [that] what entropy is, deep down in its guts, is a way [of] counting the number of ways you can rearrange atoms or elementary particles or what have you without noticing macroscopically, right? So, if we have an egg, you notice that there is an egg shell and a[n] egg white and a yolk, but if you change some of the molecules around within the yolk you wouldn’t notice, but if you started changing yolk molecules around with egg white molecules, you would notice. So the more messy and, sort of, mixed up something is the higher the entropy, because there [are] more ways to rearrange it. So if you say that the early universe has a low entropy, which is a true statement, what you’re saying is the universe is in a very, very special state, one of only a small number of possible arrangements. So that becomes puzzling, that sounds like a clue to something that we don’t [even] understand—why was the early universe so special?
– You say in the book that the universe, isn’t really the way it „should be”?
– That’s right.
– So how should it be, how is it not that way and what does that tell us?
– Well, that’s part 4 of the book. We talk about, you know, now that we’ve gone through what entropy means and what its puzzle is in part 3, in part 4 we try to relate it cosmology, relate to what we know about the observable universe. And again I try to be clear that the question, what should the universe look like? is not one we have one clear, obviously correct answer to. We can sort of make some guesses, but when we think about entropy and we think that high entropy corresponds to a natural state, there are many, many, many ways to be high entropy. Low entropy corresponds to something delicately tuned, so that’s why it’s easy for entropy to go up. There’s more ways to be high entropy than low entropy. So if the universe is low entropy then it’s delicately tuned, and that doesn’t seem the way that it should be. [You know,] what did the tuning? It’s okay to imagine that the universe is in a low entropy state, but it seems to imply there’s an explanation, there’s a mechanism, there’s some laws of physics that makes the universe that way at early time[s]. So in part 4, I go through a bunch of possible explanations that you might consider, and tell you why none of them are really very satisfying. And in the end I suggest that, well maybe our universe is part of a much bigger multiverse, that the universe we see is not all there is; there are other regions and our big bang is actually part of a much bigger system that has [a high] entropy [but] never[theless] the entropy can get higher and higher by the much bigger universe creating new universes, and we’re a baby universe that branched off of a much bigger system. It’s very, very speculative, it’s not something that I’m proclaiming to be necessarily the right answer, but what I try to emphasize is that something like this is what we need to be thinking about. We need to be thinking about models for the large-scale evolution of the universe, where the big bang is not the beginning, the big bang is explained by something preexisting to that and that’s really the only hope I think we have of dynamically coming up with a reason why our observed universe had a low entropy at early times.