Supernovas Illuminate Dark Energy

Einstein called it his biggest blunder. His early equations for general relativity accounted for a strange cosmic antigravity precisely balancing the attractive force of gravity. But after Edwin Hubble discovered that the universe is expanding, Einstein yanked the mysterious force from his equations. Several years ago though, UC Berkeley astronomer Alex Filippenko helped prove that Einstein was right after all. The universe is not only expanding, but it's speeding up every day. Filippenko is now asking why and how fast, using exploding stars as his cosmic mile markers.

Neurobiology's Lighter Side

What happens when you touch a hot pan on the stove? You probably yell and yank your hand away. Between the sizzle and the scream though, an amazingly fast and complex cascade of cellular communication occurs inside your body. To study the electrical intricacies of the nervous system, neurobiologist Ehud Isacoff is developing new optical methods that enable scientists to watch the cellular symphony unfold at the nanoscale.

A Twist on Cancer DNA

Crammed inside every human cell are numerous strands of chromosomal DNA that, if laid end-to-end, would span a distance of about two meters. A special enzyme mechanically untangles the DNA, keeping our chromosomes from resembling a string of Christmas tree lights jammed into a box after the holiday. Someday, biochemist James Berger's efforts to understand the same enzyme in cancer cells could lead to new tumor-fighting drugs.

A recipient of UC Berkeley's two most coveted teaching awards, Alex Filippenko is also the co-author of the introductory astronomy textbook, "The Cosmos: Astronomy in the New Millennium." (photo by Jock McDonald)