I was very lucky today to be allowed to hear Professor Joseph Silk (currently Professor of Physics at the Institut d’Astrophysique de Paris, Université Pierre et Marie Curie and Homewood Professor of Physics and Astronomy at Johns Hopkins University, formerly the Savilian Chair of Astronomy at the University of Oxford from 1999 to September 2011) expound upon the very latest findings in Astronomy, Astrophysics and Cosmology, literally straight hot off the press, since the latest findings from the South Pole observations were reported on the BBC only last week.
Astronomers peer back into the past with the world’s largest telescopes. They see billions of galaxies, and they find indications of evolution and youth. Before the first galaxies, there were the Dark Ages. And before then, the Big Bang. But there is much of the universe that astronomers cannot probe. Professor Silk describes the universe that we see, and speculate about the universe we cannot see. He describes the past, with some confidence, and will speculate about the future, as perceived by cosmologists, under the assumption that humanity survives to reap the potentially infinite rewards of what to all intents and purposes is an infinite, or at least an inconceivably large universe.
The room, one of the largest lecture theatres in the University of Portsmouth, was packed with between 120 and 150 avid listeners. As his text Professor Silk took a 1669 quotation from Blaise Pascal “Nature is an infinite sphere whose centre is everywhere and whose circumference is nowhere”.
Professor Silk started his exploration with Huddle and the red shift of galaxies implying expansion shortly after the Big Bang. He also paid tribute to the work of Lemaitre and Friedman both of whom managed to work out ‘expansion’ before, and separately from, Huddle. Next he outlined George Gamow’s 1949 work on Fossil Radiation of the Big Bang then Fowler’s 1957 paper on the creation of various elements up to (stable) iron in succession through ‘generations’ of star formation, then Rubin and Zwicky’s work on Dark Matter and Galaxy Clusters through gravity, Penzias and Wilson’s 1964 work on dark matter mapping through lensing and ending with Linde and Guth’s 1980 developments from expansion to inflation.
Finally he covered the fascinating new work recently reported where gravitational waves have been detected at 10-35 seconds after the Big Bang using BICEP2
Finally he rounded out his fascinating lecture with some recent statistics which indicate that:
- Dark Energy is invisible but constant
- 21% of the Universe is dark matter
- 75% of the Universe is dark energy
- only 4% of the Universe is formed of atoms