It was a pleasure to have Dr. Rachel Rosen, Assistant Professor of Theoretical Physics at Columbia University, give a lecture on the New Developments in Gravity. Dr. Rosen is an expert in areas of research pertaining to field theory, cosmology, and particle physics. She is recognized for her contributions to the theory of massive gravity, a modified theory of gravity. In the lecture, she explained to us that the currently accepted standard theory of gravity is Albert Einstein’s general relativity. In this theory, the graviton (the particle responsible for the force of gravity) is a massless particle. However, Dr. Rosen stated that people have been interested in whether or not it's possible to modify this theory of gravity, particularly at large distances. One way to do this is to give the graviton a mass and make it a massive particle. Recently, it has been shown that it is possible to have theoretically consistent theories in which the graviton has a mass. The recent discovery of dark energy and the associated cosmological constant problem has prompted investigations for long distance modifications of general relativity. Dr. Rosen believes that making the graviton a massive particle may lead us to understand natural phenomena like the observed expansion of the universe.
After the main lecture, graduate student, Stephanie Douglas, gave a brief talk on star-forming regions in open clusters. She showed images of open clusters such as Trumpler 16, Pleiades, Hyades, Alpha Persei, all ranging in age between 500,000 and 680 million years. Stephanie explained how some of the open clusters have regions that glow differently in different parts of the light spectrum (i.e., visible versus infrared). She explained that when look at regions obscured by gas and dust in at different wavelengths we can pick out areas where stars are being formed.
After the lecture, audience members headed up to the roof to see the Moon, Jupiter, and the Orion Nebula. Graduate student, Adrian Price-Whelan, set up a digital SLR camera in the Big Dome to demonstrate how it's still possible to see faint sky objects, even from the heart of New York City. The image below was taken through our 14" Meade telescope.
-- David Jaimes (post-back student)