Does Dark Matter Matter?
Physicists are strange people. They may look normal, but there are very strange things going on in their heads. Take, for instance, their “discovery” of dark matter and/or dark energy. But first, a digression.
I was in a small group that received a detailed briefing and tour at CERN, the European Organization for Nuclear Research. It’s based near Geneva and is famous for having a dug a humongous 17-mile tunnel in a perfect circle through parts of Switzerland and France (proving that France really isn’t useless). This was about 20 years ago, and the tunnel, known as the Large Hadron Collider (LHC), was years away from being finished. I went into one part of the LHC under construction, a huge space surrounded by magnets, cables, and lots of gadgets and widgets.
Before the trip underground, CERN gave us a briefing that lasted a couple of hours. That’s where I learned that there are things smaller than protons, neutrons, and electrons. These little suckers are called quarks. The six they talked about come in flavors and have names: up, down, charm, strange, top, and bottom. I’m serious. For all I know, they’ve found some more quarks since then, maybe Fred and Ethel. These quarks never exist alone; in various combinations they form hadrons, like protons and neutrons. As I understood it, they are going to fire hadrons (protons and such) around the LHC at nearly the speed of light, using magnets and in a temperature of about -271 Celcius. The idea is to make the hadrons collide and break apart, freeing the quarks. I guess that’s good, at least from a quark’s point of view, and it’s supposed to tell us something about The Big Bang. Watch this fascinating video of how it’s supposed to work.
But there was a physicist named Werner Heisenberg who long ago threw a monkey wrench into the works with the Heisenberg Uncertainty Principle. It says that you can’t measure stuff like this because the more precisely you measure one variable, the less precise the measurement of a related variable. Something like that. In other words, you can’t measure what these things are doing because measuring makes them unmeasurable. Einstein strongly disagreed. I’ll go with Einstein.
Anyway, CERN finally fired up the Large Hadron Collider a few months ago. That was a bit controversial, causing folks who wear hats made of tin foil and bent coat hangers to theorize that the LHC was going to start a chain reaction of some kind or create black holes and destroy the world. Didn’t happen. In fact, not much of anything happened. The damn thing broke. The explanation was that the LHC got a hitch in its getalong, but that’s too technical to explain here. They’re promising to fire it up again next year.
Now, there are physicists who study things at the micro level, like quantum mechanics. They’re the ones who want to shoot quarks or whatever through a tunnel under Switzerland and France. There are other physicists who study things at the macro level, like astrophysics. E.g., Einstein, Hawking, etc. These two bunches are like the Yankees and the Red Sox—no love lost between them.
Anyway, to dark matter. After all these years of studying the heavens, it was obvious that there were very large areas of complete darkness. Kind of like West Virginia at night. So the physicists, being who they are, came up with a theory that said there isn’t nothing out there, there’s something. NASA explains it:
Most of the stuff in clusters of galaxies is invisible and, since these are the largest structures in the Universe held together by gravity, scientists then conclude that most of the matter in the entire Universe is invisible. This invisible stuff is called ‘dark matter‘. There is currently much ongoing research by scientists attempting to discover exactly what this dark matter is, how much there is, and what effect it may have on the future of the Universe as a whole.
Since we can’t see it, we’ll call it dark matter and/or dark energy, and what the heck, let’s say it counteracts gravity. Since this dark energy (or matter) is a wee bit stronger than gravity, the universe is expanding. Something like that. But since the expansion of the universe is speeding up, it may be that the strength of dark matter and/or dark energy is growing. If that keeps up, it’s theorized, we might suffer a “big rip” in which the universe is blown to smithereens. That could happen in something like 50 billion years. Our tireless physicists are working overtime to explain all this. As quoted by Joel Achenbach in the Washington Post,
“Even nothing, even empty space, weighs something, and because in our universe we’ve got a lot of nothing, it has a major effect on our evolution and causes space itself to accelerate,” said David Spergel, an astrophysicist at Princeton University.
“We’ve discovered this incredible dark energy; we don’t understand what the hell it is,” said Lawrence M. Krauss, a physicist at Arizona State University.
But don’t worry too much. Apparently, observations of something-or-other have resulted in a re-evaluation of all this, and we’re probably not going to have a big rip. Whew! And here I was, worrying that in 50 billion years or so me and Cat might get launched into outer–somewhere.
Joel Achenbach, who’s been worrying about this lately, concluded on his blog that since no one, including the physicists, really knows anything about this stuff, we have to fall back on the Anthropic Principle:
The Anthropic Principle states that the universe has the physical properties that we perceive because if it had other properties we wouldn’t exist. If dark energy were more powerful, for example, galaxies would never have formed, and there’d be no planets, no astronomers, no one to ask these questions.
A corollary is that there are an infinite number of universes, almost all of which evaporate or collapse upon themselves in the blink of an eye. Perhaps the ratio of the mass of the electron to the proton is a little off, and matter isn’t stable. Perhaps gravity is too strong, and all you wind up with is a dense little wad of spacegunk. And so on.
You can look up all this stuff on Wikipedia, at the risk of serious damage to your psyche. Don’t say you weren’t warned!
Now that I’ve done my public service for the day by helping you understand dark matter and/or dark energy, let me know if you would like me to explain something equally obscure. For example, the college football ranking system, in which teams with more wins can be ranked lower than teams with fewer wins, and teams with fewer losses can be ranked lower than teams with more losses. But hurry; physicists are working on the problem, and you don’t want them explaining it.
(This article was also posted at Opinion Forum.)