In the final pages of chapter 2 of The Atheist’s Guide to Reality: Enjoying Life Without Illusions, Alex Rosenberg turns to some big, persistent questions he believes are now answered by physics.
– Where did the universe come from, how long ago, and where is it going?
Rosenberg accepts the standard view that the universe began with a “big bang” about 13.75 billion years ago (13.80 according to the latest Wikipedia update). The universe started out extremely hot and extremely dense and has been expanding ever since, creating spacetime, subatomic particles, the elements, stars and galaxies along the way. The expansion seems to be speeding up, but it’s not clear why.
Rosenberg gives the impression that the universe began as a tiny sphere, reaching the size of an orange in much less than a second. The physicist who answers questions at the “Ask a Physicist” website, however, says that the universe didn’t really explode from a tiny point, despite what every documentary and planetarium show implies. He says we should think of the early universe as being like an infinite, very hot, very dense rubber sheet that suddenly began to stretch (although he admits that it’s hard to picture something infinite becoming larger without doing the math).
One aspect of the big bang that’s always bothered me is its location. Physicists often imply that it didn’t have a location, since spacetime didn’t exist before the big bang occurred. Rosenberg, however, says there is a small region of space where the cosmic background radiation is more intense than anywhere else. He refers to this as “the source of the big bang”. The “Ask a Physicist” physicist says that the oldest light we can detect came from somewhere 46 billion light-years away, much further away than the 14 light-years we would expect from the age of the universe (the difference is the effect of cosmic expansion). So if there is a region of space some 46 billion light-years away that appears to have been the location of the big bang, I have dibs on running the first snack bar and gift shop.
– Where did the big bang come from?
Rosenberg favors one of the leading theories:
The best current theory suggests that our universe is just one universe in a “multiverse” – a vast number of universes, each bubbling up randomly out of the foam on the surface of the multiverse, like so many bubbles in the bathwater, each one the result of some totally random event.
Of course, I have no idea whether the multiverse theory is correct, but it doesn’t seem right to assume that whatever happens in the multiverse is totally random. Most physicists believe that events at the quantum level in our universe are random, but others think that there might be non-random causes underlying the quantum level. Even if quantum events in our universe are random, why assume randomness to be the rule in other universes or in the larger multiverse? Maybe randomness or apparent randomness is simply a feature of the universe we live in.
Rosenberg is certain that everything that happens at the quantum level in our universe, everything that happened in the pre-big bang universe, everything that happened before that in the multiverse, and even everything that is happening in the multiverse right now is fundamentally random. But this seems like conjecture on his part, especially since nobody knows what physical laws were in effect before the big bang or are in effect in the multiverse (if such a thing even exists).
– Why is there something rather than nothing?
Some philosophers, scientists and theologians consider this to be the deepest question of all. According to Rosenberg, the answer is:
No reason at all. It’s just another quantum event. What science and scientism tell those who hanker for more is “Get over it!”
If Rosenberg is simply telling us what today’s best science has to say about the origin of all existence, he’s probably right. Either there has always been something (there never was a first cause or a prime mover) or one day something simply happened to pop into existence. Rosenberg’s project, however, is both to explain what science tells us and to convince us that scientism provides the answers we need to live without illusions (“the methods of science are the only reliable ways to secure knowledge of anything” and “science provides all the significant truths about reality”). I think it would be more rational to confess that we don’t know and may never know why there is something rather than nothing. Science might be the most reliable way to secure knowledge, but it hasn’t given us knowledge of everything.
– What is the purpose of the universe?
As should be expected by now, Rosenberg’s answer is short and to the point. There isn’t any purpose to the universe at all. He points out that physicists have been tremendously successful at explaining natural phenomena without resorting to purposes (what philosophers call “teleological” explanations). Smoke doesn’t rise because its purpose is to get higher. Rosenberg is sure that the universe wasn’t created as someone’s science experiment and we aren’t all living in some kind of enormous virtual reality contraption. He’s probably right, but it seems to me that he’s going beyond science here. The best that can be said in support of his position is that, according to the best science we have, the universe functions without purpose. Contemporary physicists don’t need to invoke purpose or purposes to explain what happens in the universe. Furthermore, there is no reason to suppose that future physicists will need to invoke purpose to explain why there is a universe, assuming that they are ever able to come up with an explanation at all.
– Why does the universe have the laws of nature and the physical parameters that make intelligent life possible?
It’s often pointed out that if the laws of nature or the basic physical parameters (like the charge on an electron) were slightly different, the stuff we’re made of couldn’t exist, so neither would we. Physicists have come up with different explanations for this fact of life (the theoretical physicist Lee Smolin offered a theory called “cosmological natural selection” in his book The Life of the Cosmos). Of course, some thinkers have concluded that God must have designed things this way to make a nice home for people like you and me. Having accepted the multiverse theory as the best theory we have, however, Rosenberg concludes that we’re just lucky. Given that a multitude of universes have arisen from the multiverse, it stands to reason that some of them are like ours. We won the cosmic lottery.
Maybe he’s right (although some days I don’t feel like a winner). Personally, I’m reserving judgment.
Coming up in part 8: “How Physics Fakes Design”.