The 2011 Nobel Prize in Physics

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Speaker: Dr Tamara Davis (University of Queensland)
Date: 14th October 2011

In the 1990s astronomers from around the world competed to determine whether the universe was decelerating strongly enough to recollapse, or whether it would expand forever, using measurements of far away supernovae. Their discovery would drastically change our understanding of the universe and ignite one of the greatest searches in modern times – the search for dark energy.

If you throw a ball up in the air, it comes back down, that is, unless you threw it fast enough that it escapes the earth’s gravitational pull – but even then, it will continue to slow down as it gets further away. So also, it was thought that the expansion of the universe started by the Big Bang may one day turn into contraction or, at least, slow down over time. That is, until 1998, when astronomers discovered that gravity is not slowing the expansion at all, the expansion is in fact, speeding up.

This year, the Nobel Prize in Physics was award to Brian Schmidt, Saul Perlmutter, and Adam Riess who, along with dozens of collaborators, made this discovery 15 years ago. Resident astrophysicist Dr Tamara Davis, works in the rapidly growing field created in the wake of the 1998 discoveries, and has worked with all three of the Nobel Laureates, coauthoring a dozen papers with them on this topic. She will give us an expert account of the events that lead up to the 1998 discovery and its consequences that continue to be a source of great mystery and excitement.