I hugely enjoyed this week’s conference ‘Cosomolgy and the Constants of Nature’ at Cambridge University. There were some truly great talks by John Barrow, John Ellis and Thanu Padmanabhan among others, not to mention Joao Magueijo describing his famous ‘variable speed of light’ theory in person. The icing on the cake was that my visit coincided with this week’s announcement of the detection of gravitational waves from the infant universe by the American BICEP2 experiment. If correct, the signal gives very significant experimental support for the theory of cosmic inflation, as well as the phenomenon of gravitational waves predicted by general relativity…..a double whammy if ever there was one.
Yesterday, I was priviliged to attend a seminar on the new results given by George Efstathiou and Anthony Challinor, team leaders on the rival Planck experiment (EU). There’s nothing like hearing a new observation dissected by a rival group and the seminar certainly didn’t disappoint. Both Cambridge physicists concluded that the BICEP 2 result is very robust, at least at face value, with the caveat that the signal needs to be reproduced at more than one frequency. The other caveat is that although the sensitivity of BICEP2 is up to ten times that of Planck, there is a certain tension between the BICEP2 data and last year’s published data from Planck. I was particularly interested in Professor Efstathiou’s comment that the differing data of the two experiments may be a genuine effect, i.e., may represent some new physics at wide angles (Planck) that doesn’t affect the BICEP2 (small angle) measurements . The next few months should be very interesting indeed for cosmology…(see here for a rigorous discussion of the BICEP2 data by Peter Coles).
I had my own private excitement when I was introduced to Stephen Hawking for the first time. It was a very moving encounter, Professor Hawking remembered my father and his work. Stephen was also very interested in our recent discovery of Einstein’s unpublished attempt at a steady-state model of the cosmos. Indeed, his first remark to me was that steady-state cosmic models were the dominant cosmic paradigm when he started his research career at Cambridge all those years ago. He asked me to send him a copy of Einstein’s paper and I had a stressful evening trying to do so as my college email chose that day to block me for not changing my password often enough – of all days for that to happen!
I can’t quite believe this photo
All in all, it was yet another hugely productive visit to Cambridge University. Every time I come here something dramatic happens but I’m also looking forward to going home, I could do with a rest!
Farewell to Clare college
The American National Pubic Radio ran a piece on our Einstein discovery on today’s Morning Edition. I think it’s quite nice, apart from the usual emphasis on Einstein’s ‘blunders’ (why do journalists always see explorations as blunders?) Still, I’m learning not to be too precious about media stuff…