In a mathematically perfect universe, we would be less than dead; we would never have existed. According to the basic precepts of Einsteinian relativity and quantum mechanics, equal amounts of matter and antimatter should have been created in the Big Bang and then immediately annihilated each other in a blaze of lethal energy, leaving a big fat goose egg with which to make stars, galaxies and us. And yet we exist, and physicists (among others) would dearly like to know why.
Thus writes Dennis Overbye in today’s New York Times. What he is getting at is the strange fact that there is more matter in the universe than there is antimatter. Yes, antimatter is real, just as real as the stuff that you and I are made of: protons, neutrons, electrons. Each of these -ons have their corresponding anti-ons: the proton has the antiproton, the neutron has the antineutron, and the electron has the positron. Two things make a particle different than its antiparticle: (1) it has the opposite charge, and (2) it has the opposite spin. (Yes, spin. Just think of particles like little spinning tops. This isn’t technically correct but it will do.) We produce antiprotons, antineutrons, and positrons in laboratory experiments all the time, but they don’t live very long because once they meet up with one of their normal -ons, which are everywhere, they annihilate one another *poof* in a burst of light. We have even managed to build a few antihydrogen atoms: Antiproton nucleus, positron in orbit. Cool, huh? Oh, you know it’s cool.
But the Big Bang theory (which, despite the claims of some, stands on better ground every day) says that there should have been equal numbers of particles and antiparticles in the early universe. But the problem is, we’re here. This is a problem because those equal numbers of -ons and anti-ons should have annihilated one another *poof* a long, long time ago. Therefore there should be nothing. So what gives? Why does the universe consist of matter? Where did all the antimatter go? The good folks at Fermilab think they have a clue, and it has to do with some rather exotic -ons known as muons and neutral B-mesons. Read about it here or, if you’re up to it, here.
The point for us is: There exists a deep asymmetry in the universe that makes everything possible. Scientists call this a broken symmetry. Such imbalances help to keep the universe rolling. Asymmetries are good in art, too: see Edward Hopper‘s Soir bleu above. The dark guy on the left is in a symmetric relationship with the clown (math and physics nerds who read this will prefer to call the dark guy-clown relationship antisymmetric, but no matter). They even hang their cigarettes at the same angle. Now, here’s the great thing about the painting: It’s not the symmetry but the stark asymmetry introduced by the column (or whatever it is) that cuts the painting into two uneven frames and effectively isolates the dark guy. Try to imagine the painting without that vertical break; it would not be nearly so interesting. “Asymmetry creates interest.” Thus spake my art-major wife in our early years, and she’s right. What she didn’t know is that asymmetry is responsible for our very existence. And I think our existence is very interesting.
Of course the Hopper makes for a pretty strained analogy, but I like it anyway. There are other asymmetries. For example, one may be tempted to think that science and theology create a nice Yin-Yang kind of symmetry, but they don’t. They don’t balance each other. They are not simply complementary ways of understanding the world. I have yet to formulate exactly what I mean here, but I have never liked the idea (rather, the cliché) that “science works with questions of fact and theology works with questions of meaning.” In particular I do not like Stephen Jay Gould‘s idea of “non-overlapping magesteria.” It just can’t be that way.
Why? Because we live in one universe. And I can’t bring myself to divide it into neat boxes, asymmetrically or otherwise.