Department of Astronomy & Physics
In the first MacLennan Memorial Lecture in Astronomy, Dr. Filippenko (Berkely) will discuss Dark Energy.
We expected the attractive force of gravity to slow down the rate at which the Universe is expanding. But observations of very distant exploding stars (supernovae) show that the expansion rate is actually speeding up, an amazing discovery that was honored with the 2011 Nobel Prize in Physics to the teams’ leaders and the 2015 Breakthrough Prize in Fundamental Physics to all team members. Over the largest distances, the Universe seems to be dominated by a mysterious, repulsive “dark energy” – an idea Albert Einstein had suggested in 1917 but abandoned in 1929 as his “biggest blunder.” It stretches space itself faster and faster with time. But the physical origin and nature of dark energy, which makes up about 70% of the contents of the Universe, is probably the most important unsolved problem in all of physics; it may provide clues to a unified quantum theory of gravity.