Speaker: Professor Tom Murphy, UCSD
Topic: “Testing Einstein’s General Relativity using Lasers and the Moon”
Time: 6:30 pm, Tuesday, May 5, 2015
Place: North Education – 60, Free Campus Parking in Parking Structure 1, levels 1&2
45 years ago, astronauts placed special reflectors on the Moon for the purpose of improving tests of gravity. Lunar laser ranging is now the best way to test key features of gravity–as formulated by Einstein’s theory of General Relativity. This talk will highlight the basic ideas of General Relativity, why we want to test it further, and how we do so by achieving millimeter-level range precision in measurements of the Earth-Moon distance. Other tidbits will include the story of dusty reflectors, the re-discovery of a lost Soviet rover, and a scary list of subtle effects we must consider to get the science right.
Tom Murphy grew up in Chattanooga, TN, where he developed an enthusiasm for telescope-building and astronomy. As an undergraduate student at Georgia Tech, he split his time between Atlanta and Washington, D.C. where he was a co-op student at the Naval Research Lab. In graduate school at Caltech, he built an infrared spectrograph for the Palomar 200-inch Telescope and used it to untangle train-wreck colliding galaxies. Dr. Murphy started the lunar ranging project with colleagues at the University of Washington where he spent three years as a post-doc. Prof. Murphy came to San Diego in 2003 where he has continued to work on the lunar ranging project, but also developed an airplane detector for telescopes and contributed substantially to public communication of energy/growth challenges through his popular quantitative blog, Do the Math.