Dark Energy talk in Berkeley

October 19, 2009.
Mommy and I rushed through the long line on Addison Street in Berkeley. We arrived in the building, went up the elevator and arrived at the mezzanine EE-FF. We were going to attend a talk about dark energy presented by the Berkeley Lab, in a series of talks called "Science at the Theater". This talk was given by Dr. Saul Perlmutter, Dr. David Schelgel and Dr. Alexie Leauthand. The interviewer was John Fowler.

They started with Dr. Perlmutter talking about dark energy. The theory is that dark energy makes the universe expand. Edwin Hubble looked at distant galaxies and noticed that they were redshifted, which means that they were going farther from us and so the universe is expanding.

Next it was Dr. Schelgel's turn. He was working on the Sloan Digital Sky Survey which was mapping space in 2D and 3D and the spectrum of the sky for a "standard ruler" of history.

Next it was Dr. Leauthand's turn. She first started with telling her audience that Fritz Zwicky calculated the speed of some galaxies, their mass, and did some calculations to find out the distance from Earth to the galaxies. But that did not match the observed distance. Zwicky concluded that there needs to be some mass in addition to the observed mass and called it "dark matter". Currently no probes have been sent to detect dark matter. People think that dark matter is a particle. Dark matter is found in galaxy clusters in clusters. Light curves through dark matter. Dark matter doesn't interact with atomic matter so it is difficult to detect it. Dark matter doesn't have anything to do with dark energy.

We left the mezzanine, went down the elevator to the first floor, crossed the street, entered the parking garage, went to our van and returned home.