So many books, so little time, so let’s get right to my suggested light summer reading. Well, I guess it’s a bit heavy. I finally dove into some Roger Penrose, and immediately drowned, as per my expectations. If you’ve never heard of Penrose, just think of Einstein and Hawking, who might not even be his equals.
It’s rare to find a mathematician professionally interested in the real world, but Penrose is also one of the world’s leading cosmologists, and his latest book, “Cycles of Time,” introduces a new model of the universe: one with no beginning or end. He says, “Our universe is what I call an aeon in an endless sequence of aeons.”
Cosmology is the study of the origin and development of the universe, something that’s intrigued me since my teens. I’ve been a fan of the closed universe model – expansion followed by collapse and a new Big Bang – for most of my life, which I first encountered in a marvelous short story by Isaac Asimov, “The Last Question.” To introduce it, and Penrose’s theory, we need a very big, little word: entropy, which you can think of as the measure of disorder in a system.
One of the fundamental questions of life is some variation on “How did the living room get so messy?” After all, it started the week clean – a low entropy state – but gradually got more cluttered: a high entropy state. And as we all know, as it gets messier, it’s less usable and you can’t find the TV remote or the magazine you were reading. And, as we also know, it takes a good deal of energy to maintain that low entropy state.
So I was saddened when the closed universe model was replaced by a couple of possible “inflationary” universes. For someone who doesn’t believe in an afterlife, the closed universe is the next best thing, as a brand-spanking new universe in a possibly infinite series of Big Bangs replaces an aging, infirm universe. We don’t go on, but the universe does.
But in the inflationary scenario, most of the energy in the universe moves from a usable state to an unusable one, what used to be called the “heat death” of the universe. Stars burn out, entropy increases, and the universe just goes on forever, with almost no energy and certainly no life.
And that brings me back to Asimov and a story he wrote in 1956. He postulated a supreme intelligence – a kind of super-computer – called Multivac. Its attendants were musing about the end of the universe one day and asked it, “How can the net amount of entropy in the universe be massively decreased?” To which Multivac replied (and continued to reply, as the question was asked again and again over billions of years), “insufficient data for meaningful answer.”
Penrose has an answer and suggests, “The universe as a whole is to be seen as an extended conformal manifold consisting of a (possibly infinite) succession of aeons, each appearing to be an entire expanding universe history.” Trust me, that’s as close to ordinary language as he gets.
Asimov’s solution was a bit simpler. As Multivac evolved into a galactic entity, existing only in hyperspace, it pondered the question long after all matter and energy (and people) were gone. It pondered and pondered some more, finally finding a solution, and said, “LET THERE BE LIGHT!”
And there was light.