Alan Boyle uses the occasion of Neal Turok’s appointment as executive director of the Perimeter Institute for Theoretical Physics to interview the scientist on topics dear to the heart of Centauri Dreams readers. The ekpyrotic universe idea championed by Turok uses the idea of multidimensional ‘branes’ whose occasional collisions spark events like the Big Bang. A cyclic model emerges that sees multiple ‘bangs,’ using today’s accelerating universe as a condition for the arrival of the next cycle. It’s fascinating stuff, but does it assume the eventual validation of string theory? Boyle quotes Turok:
“In my opinion, string theory is the most promising avenue we have for the unification of gravity and the fundamental forces. But that doesn’t mean I’m not critical of it. I think sometimes people do exaggerate its achievements thus far. We need to keep an open mind.”
Turok, as director of Cambridge University’s Center for Theoretical Cosmology, worked with Princeton’s Barry Steinhardt on Endless Universe: Beyond the Big Bang (Doubleday, 2007), which belongs on your bookshelf. Did an exhausted earlier universe help to spawn the one we live in today, and is another one likely to form a trillion years from now? Don’t look for experimental evidence any time soon, but the ekpyrotic universe is a model whose startling conclusions may offer insights into both dark matter and energy, and the role of each in the universe’s growth. Ekpyrotic, incidentally, derives from the Greek word for ‘conflagration.’
Other weekend reading might involve the latest Carnival of Space, held this week at the Space Cynics site. This week I’ll send you to Bad Astronomy‘s essay on the role our position in the galaxy may play in mass extinctions. This is Phil Plait’s take on a story we looked at briefly here on Centauri Dreams , involving the Solar System’s passage through the galactic plane, which may trigger a rain of comets from the outer system to move toward the Sun. So, at least, says a team at the Cardiff Centre for Astrobiology, which can point to our current galactic position as a sign that we may be nearing another such period. Check as well Brian Wang’s treatment of the laser comb technology we looked at yesterday.