From Mars to the Multiverse

Apr 13, 2018 - 7:00 pm to 8:15 pm

NVIDIA Auditorium (475 Via Ortega, Stanford, CA 94305)

Sir Martin Rees (Professor University of Cambridge)

Powerful instruments have led to astonishing progress in tracing the emergence of atoms, galaxies, stars and planets from a mysterious 'beginning' 13.8 billion years ago. An exciting development  has been the realization that many other stars are orbited by retinues of planets – some resembling our Earth (and capable of harboring life).

Looking further afield, observers can probe galaxies and the massive black holes at their centers back to an epoch only a billion years after the 'Big Bang'.  Indeed we can trace pre-galactic history with some confidence back to a nanosecond after the 'Big Bang'.

But the key parameters of our expanding universe – the expansion rate, the geometry and the content -- were established far earlier still, when the physics is still conjectural but is being constrained, especially by precision measurements of the microwave background. These advances pose new questions: in particular, was our 'Big Bang' the only one? If there are others, would the physical laws within them be the same as in ours – or (as some string theorists conjecture) would the laws be different? The structure of our universe and the emergence of stars, planets and life within it are dependent on the values of a few basic microphysical and cosmological numbers. I will discuss the consequences of tweaking the values of these numbers. This exercise is of course a necessary strand of cosmological research if there are multiple vacuum states or if 'eternal inflation' leads to a multiplicity of big bangs. However, even those who are allergic to the 'multiverse' may have their intuition developed by exploring these alternative scenarios -- just as some historians explore counterfactual scenarios, such as what might have happened if the Brits had fought harder in 1776. This illustrated lecture will attempt to address such issues.

About the Speaker

Martin Rees is a cosmologist and space scientist. His research interests include galaxy formation, active galactic nuclei, black holes, gamma-ray bursts, and more speculative aspects of cosmology. He is based in Cambridge, where he has been Director of the Institute of Astronomy, a Research Professor, and Master of Trinity College. He was President of the Royal Society (the UK's academy of science) during 2005-2010. In 2005 he was appointed to the UK's House of Lords.

He has received many international awards for his research, and belongs to numerous academies including the National Academy of Sciences, the Russian Academy and the Pontifical Academy. He is on the Board of the Princeton Institute for Advanced Study and has served on many bodies connected with international collaboration in science — and especially threats stemming from humanity's  ever-heavier 'footprint' on the planet, and the runaway consequences of ever more powerful technologies. He chairs the advisory group for the 'Breakthrough Listen' project to search for extraterrestrial intelligence.

He lectures, writes and broadcasts widely for general audiences. His books include 'Before the Beginning', 'Our Final Century?' 'Just Six Numbers', 'Our Cosmic Habitat', 'Gravity's Fatal Attraction' (with M Begelman), and 'From Here to Infinity: Scientific Horizons'. A further book, 'On the Future', will appear in October.

Venue and Parking

This lecture will take place on the Stanford main campus, in the NVIDIA Auditorium, Huang Engineering Center (475 Via Ortega, Stanford, CA 94305).

Parking is available on the Stanford Campus and is free of charge and open to all after 4pm (in either visitor spaces or those designated for A or C permits). The most convenient parking is located within the Via Ortega Garage (285 Panama Street, Stanford).

Parking Map