Spring Ahead
Listen 6:22
Remember to advance your timepieces one hour before retiring Saturday night; Daylight Savings Time starts Sunday morning at 2:00 am.
Dr. Pitts has returned from a visit to Mt. Wilson and Carnegie offices in Pasadena, California. In the 1920s, Edmund Hubble collected spectroscopic data on galaxies there, showing that they were moving away from the Milky Way. As the distances to galaxies increased, the faster they seemed to be moving.
Since then, we’ve come to understand that the increasing recessional velocity of galaxies (as was suggested by Einstein) actually is caused by the expansion of the universe pulling everything apart.
Hubble also figured out a rate of expansion, now called the Hubble Constant, that tells us about the early state of the universe.
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Skytalk is hosted by WHYY's Dave Heller. Each week he discusses the latest news in astronomy with Dr. Derrick H. Pitts of the Franklin Institute.
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