Matters of gravity
AbstractContrary to popular belief, on very large distance scales visible matter stubbornly refuses to "fall" according to the laws of gravity of both Newton and Einstein. The paradox has led to the introduction of dark matter, purporting to explain the observed surplus of gravitational pull. The logical possibility remains that there is no dark matter, what you see is all there is, and that the paradox simply signals the break down of the Einstein-Newton theory of gravity. I will review alternative theories of gravity that do away with the need for dark matter. Surprisingly Solar system gravitational experiments, such as those associated with the LISA Pathfinder mission, might settle the score between the two approaches.
About the talk
Imperial College London, UK
About the speaker
João Magueijo is a Portuguese cosmologist and professor in Theoretical Physics at Imperial College London. He is a pioneer of the varying speed of light (VSL) theory.
João Magueijo studied physics at the University of Lisbon. He undertook graduate work and Ph.D. at Cambridge University. He was awarded a research fellowship at St John's College, Cambridge, the same fellowship previously held by Paul Dirac and Abdus Salam. He has been a faculty member at Princeton and Cambridge, and is currently a professor at Imperial College London where he teaches undergraduates "General Relativity" and postgraduates "Advanced General Relativity".
In 1998, Magueijo teamed with Andreas Albrecht to work on the varying speed of light (VSL) theory of cosmology, which proposes that the speed of light was much higher in the early universe, of 60 orders of magnitude faster than its present value. This would explain the horizon problem (since distant regions of the expanding universe would have had time to interact and homogenize their properties), and is presented as an alternative to the more mainstream theory of cosmic inflation.
Magueijo discusses his personal struggles pursuing VSL in his 2003 book, "Faster Than The Speed of Light, The Story of a Scientific Speculation". He is also the host of the Science Channel series, João Magueijo's Big Bang, which premiered on May 13, 2008.