We may be in dark times on Earth, but astronomy students are finding you can't escape just by looking up. The Daily Lobo checked in with professor Dinesh Loomba to find out more about the physics and astronomy department's research on the subject.
Daily Lobo: When did you start researching dark matter?
Dinesh Loomba: I came to UNM about seven years ago. My colleagues initially provided me with a lot of equipment when I had no grant money and urged me to pursue this area of research, which didn't exist here before. They urged me to probe new parameters in terms of research. The project is now being funded by the National Science Foundation.
DL: What does the research consist of?
Loomba: What we are doing is building detectors that will try to detect a signal. We're taking the approach to build detectors and place them deep underground in mines. The reason we place them deep underground is we use all the earth above the detector to shield cosmic rays. We don't want to see the ordinary stuff. We want to look for something that will pass right through the Earth that's weakly interacting.
DL: Are students involved in the project?
Get content from The Daily Lobo delivered to your inbox
Loomba: Yes. It's a great opportunity for students, even
undergraduates, to get involved in because it's a very small-scale experiment. In our experiment, the students build everything from the ground up. They get experience from A to Z, plus get to work on a really interesting problem, which is, "What is dark matter?"
Daily Lobo: And what do you think it is?
Loomba: The main information we have about dark matter, the main reason we think it's there, primarily comes from astronomy.... What we observe when we look at very large scales - when we look at gas or stars that are moving around a galaxy like our own spiral galaxy - we observe that the rotational velocity seems to be much faster than would be necessary to keep it in orbit. It's faster than the escape velocity, which is based on counting the amount of mass that's inside the galaxy by what we see. What we see shines light, such as stars. We can also look in the X-ray, ultraviolet and other parts of the electromagnetic spectrum to count up all the stuff we see. Then we say, "The orbital velocity at a certain distance should be ___." But these guys are moving much faster. That was the first hint. These kinds of astronomical hints have been around for 70 to 80 years. They led initially to the idea that maybe there's a lot of stuff we're not seeing. If we're not seeing it, that doesn't mean it's not there. Nature has a lot of ways to hide stuff from us. Over the years, people kept looking and counting it up, but they were off by large factors. That led to this idea that there's something dark there we're not seeing.
It's just a general name - dark matter. If you take all the stuff the universe is made out of, we believe the ordinary stuff makes up only about 4 percent of the universe. Twenty-five to 30 percent is dark matter. Another 70 percent is dark energy, which is so mysterious that we don't even have a clue about that. This dark matter problem is trying to address the question, "What is the 95 percent of the universe that's dark?"
~ Jesse Trujillo
