This video, on YouTube, is from the PBS NOVA science program.
"We can't see dark matter, and some skeptics doubt its existence, but many scientists think it makes up 20-some percent of our universe. Astronomer Doug Clowe explains how the Bullet Cluster, a group of galaxies billions of light years away, may shed some light on this mysterious stuff.
Don't miss NOVAscienceNOW, airing every Wednesday night during the summer of 2008 on PBS. Watch past episodes of the program, try out interactives, and more on our Web site: http://www.pbs.org/nova/sciencenow "
Peter Fisher, Experimental Physicist, MIT talked about his work on dark mattter on the NOVA Science Now show, The Big Deal:
"The goal of high-energy physics is to understand the smallest things. How small is small? So there are molecules, there are atoms. Inside the atoms, there's a nucleus, inside the nucleus there are quarks. What's inside the quarks? Is there anything inside the quarks? And that connects with the picture of the universe, because by looking at smaller and smaller things, we understand the biggest thing, which is what the universe looked like, looks like now.
But after 101 years of tremendous intellectual achievement and a lot of hard experimental work, we've come to the conclusion we don't understand 97 percent of the universe, which is, I think, a big shock. And kind of a reminder of how puny we are.
Now, the 97 percent breaks into two parts, dark energy and dark matter. Dark matter, there's some kind of credible ideas that it could be particles. And the new experiments at CERN may be able to tell us something about those particles. But dark energy, no clue. None. Nothing.
That leaves a few percent which we understand very, very, very well. And that's the stuff in this room and on the Earth, and we have a very good theory for that.
So I'm doing a dark matter experiment. I'm actually going to look for the dark matter that's around us. And what I'm really excited about is that we make a big step forward in the big picture. Because ultimately you want a picture of the whole universe, everything—the history, the future, now. And in the next 10 years, all of this is going to come together, I hope. So that's why I'm excited."
There are more transcripts and video segments from NOVA shows about CERN at this link.