Getting to the Gravity of the Matter

WARNING! SCIENCE CONTENT!

There’s actually a pun buried in the title of this column, but you might not find it amusing unless you have a pHd in advanced particle physics. The science community is abuzz over rumors that a research team in Italy may have discovered the long sought and highly controversial “dark matter” which some claim makes up a huge amount of the mass of the universe.

Researchers from Italy stirred up controversy eight years ago when they announced they had discovered the identity of dark matter, the invisible stuff that’s thought to make up 23 percent of the universe. Now, after a long period of silence, the DAMA (DArk MAtter) collaboration at the University of Rome is about to reinforce its claim with fresh data. That’s the rumor at the American Physical Society meeting here in St. Louis, anyway.

Before we get too excited here, it’s worth noting that not everyone is popping open the champagne bottles.

Researchers haven’t seen the new results, but they say it would take a lot to convince them that the DAMA team is really onto something.

First, let me point out that I’m not a scientist, nor do I play one on TV, but I have some problems with this entire theory. For those of you who don’t follow the science beat, let me give you the short, layman’s version of this entire dispute. Essentially, it all boils down to our understanding of the force of gravity and how very large objects behave in a gravitational field. Under the current theory, objects orbiting a star (such as planets) should move faster if they are closer to the star and more slowly if they are further away. You can observe this effect by noting that Mercury (which is very close to the sun) orbits our star at a very rapid clip compared to Neptune, for example, which spins around at a relatively liesurely pace. No problem, right?

Unfortunately, when you pull your perspective much further out something goes amiss. Our galaxy, like most (if not all) of them, rotates around a supermassive black hole at its center. So following the above theory, the stars near the center should rotate much, much faster than the ones out near the rim. (Such as ours.) The problem is, the stars – and even the random dust and gases – out here near the rim are whirling around just as fast, and sometimes even faster, than the ones near the center. This put some scientists into a tizzy and they immediately began seeking an explanation. One group of these (literal) rocket scientists came up with an explantion which relied on a vast portion of the mass in the galaxy being missing. In order to explain the observed motion under the current theory, the galaxy would have to be far more massive than the total matter we are able to observe in it. Hence, they developed the theory of “dark matter.” The problem is, though, that we’ve never seen it and we don’t even know if it exists at all.

Speculation abounds about what the matter would look like, but most of the theory’s proponents agree that it would have to be a totally new type of matter not composed of the normal atoms – protons, neutrons and electrons – that we’re used to. Now, let me explain why I have issues with all of this. I had the opportunity to sit down with a physicist from Cornell last year and ask him a few questions on the subject. He rather sheepishly admitted that, of all the forces known in the universe, gravity is the one that we really don’t know that much about. In fact, it’s difficult to say anything difinitive about gravity except that it’s a property of mass. We can’t do anything with it, unlike the other known forces. We can’t change the amount of gravity a given body of mass has and we can really only measure it by observing the effect it has on other objects. We can’t really even explain why gravity is so weak compared to the other forces. (If you find yourself doubting that, put a small iron nail on a table. The gravity of the earth holds it down. Now take one of those little magnets off of your refrigerator and hold it over the nail. The magnetic force of a magnet weighing only a few grams can overcome the graviational force generated by an entire planet.)

Here is what I find so remarkable about this entire debate. In the history of science, man as tended to observe the universe, study what is happening, and then delvelop theories to define and explain what they observe. It’s a good system and has worked well for centuries. But in this debate, we seem to see scients having a theory, then examining the universe, finding that the results don’t match their theory, and then trying to change the universe to fit the theory! Galaxy of a given mass not behaving the way it should according to your theory? No problem, friend! We’ll just make the galaxy ten times more massive than it appears! They have guys down in caves, miles below the surface, staring at huge vats of water for years on end hoping to find a particle which they can’t even define in order to shoehorn the universe into a model which fits their theory.

I wonder how many of them have actually considered the possibility that the current theory of gravity is simply not completely accurate. Perhaps gravity works differently than we think over vast distances when it involves objects of such unimaginable mass as a gigantic black hole. Perhaps such a black hole can cause “gravity bridges” from object to object across vast spans causing the stars at the galaxy’s rim to rotate quicker than we think they should. Wouldn’t a flaw in our understanding of the theory be a more likely explanation than this gigantic amount of magical mass that we can’t see, touch, feel or smell? If you’re going to go with that theory, then why not say that all of this “missing mass” is actually accounted for by God and He really needs to look into that Atkins Diet thing? And in fact, there are already some respected scientists who are saying that the whole dark matter theory may be bunk.

I’m not saying I have the answer, guys. I’m just saying that maybe you don’t either. Rather than looking for all of this missing mass, maybe we should just be taking another look at the theory and seeing if it can’t be modified to fit the observed actions. Food for thought on a Tuesday morning, dear readers. Enjoy.