Airdate: Sep 24, 2003
Scientist: Ben R. Oppenheimer
Missing Matter: Wimps
Astronomers tell us that most of the universe is made up of matter that can only be defined in theory.
Many astronomers think that thereâ€™s a lot more mass to the universe than we can detect with our telescopes. But astronomers disagree as to what the nature of this hidden mass might be. I'm Jim Metzner and this is the Pulse of the Planet. One group of scientists believes that the lion's share of this hidden mass is made up of burned-out stars too faint to be seen with today's telescopes. But another group thinks the universe might be permeated with extremely dense, and so far, undetectable particles.
â€œThereâ€™s various reasons why a lot of that material - probably most of it - is in fact, not like us, made of protons, neutrons and electrons. It's probably some sort of exotic material.â€
Astronomer Ben Oppenheimer is at the University of California in Berkeley.
"And there's a zoo of particles that have been proposed that could account for all of this material, things called axions. So there are countless names that people have conjured, and they're basically theoretical particles - no one has ever detected these things. It's very difficult to detect them. That's why they're called weakly interacting massive particles. They weakly interact with normal matter."
Well, searching for these Weakly Interacting Massive Particles, or WIMPS, presents a difficult challenge for scientists. They're trying to identify a new particle that may prove to be impossible to detect.
"One has to design a fairly complicated experiment that involves a lot of normal matter so that if many of these weakly interacting particles pass through this huge piece of normal matter, you might stand a chance of detecting it. One of those WIMPS might actually cause a reaction with the with the normal matter. But no one's succeeded in doing that yet."
Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.