The Search for Dark Energy – With Guest Dr. David Schlegel

February 18, 2013

John P. Millis, Ph.D. and Jedidiah Becker for – Your Universe Online

In 1998 scientists measuring the expansion of the Universe made a startling discovery: the expansion is actually accelerating. Prior to this point, researchers had long believed that the influence of gravity would eventually cause the expansion of the Universe to slow down.

This unexpected observation has led researchers to suspect that there may be something else at work in the cosmos, some currently unknown force that is driving the Universe apart at ever greater speeds. And while the exact identity of the culprit is still unknown, scientists are hot on the trail of a mysterious force, simply known as dark energy, that they believe may be responsible.

One of the scientists leading the way in the search for dark energy is Dr. David Schlegel, a senior research scientist at Lawrence Berkley National Laboratory and the principle investigator on the Baryon Oscillation Spectroscopic Survey (BOSS).

In this edition of Your Universe Today we spoke with Dr. Schlegel and learned how scientists are searching for evidence of dark energy, what they think the source might be, and how the recent results of the BOSS experiment are leading the way forward.


David Schlegel is a cosmologist at Lawrence Berkeley National Lab who develops instruments and analysis tools for making the largest three-dimensional maps of the Universe. The largest such map, from the Sloan Digital Sky Survey, has been used to measure the cosmic distance scale and to study dark energy.

Dr. Schlegel received his BA from Princeton University in 1989 and a PhD from the University of California at Berkeley in 1995. He was a postdoctoral fellow at Durham University and Princeton University before joining Berkeley Lab as a Division Fellow in 2004. He is currently a Senior Scientist at Berkeley Lab, the Principal Investigator of the Sloan Digital Sky Survey BOSS project, and the Principal Investigator of the BigBOSS project that is in development.