The 13.8 billion-year history of the universe condensed into a graphic, with the Big Bang followed by an inflationary epoch, to the left, and our current, developed cosmos on the right. (Image Credit: NASA via Flickr)
Inflation theory, first formulated in 1980, proposes that the universe underwent an exponential expansion a tiny fraction of a second after the Big Bang, increasing in size by a factor of about 1030. Inflation helps resolve several key issues with the Big Bang theory, the most successful cosmology model to date. One issue is the apparent "smoothness," or uniformity of temperature, of the universe's earliest observable light, the cosmic microwave background (CMB). A universe with all its regions connected in time and space prior to an inflationary period could reach such a temperature equilibrium. Inflation can also explain the startlingly precise density that our universe possesses in order to have neither collapsed upon itself, nor ballooned in size so rapidly as to have become virtually empty. Geometrically speaking, space appears "flat," rather than curved close or open. Inflation would have stretched out any local curvature of space making this curvature indiscernible, rather like how the planet Earth appears flat to those standing on its surface. In addition, irregularities in inflation caused by fluctuations predicted by quantum mechanics in the fabric of space-time can explain the clumping of mass into the observable clusters of galaxies in the universe. Researchers continue to study the CMB and cosmic structure for clues about inflation.
Following the release of the National Research Council's Astronomy and Astrophysics decadal survey, survey chairman Roger Blandford and committee member Michael Turner discuss Astro2010, as well as the current and future directions of the fields.
Central to the science of cosmology is the zeal to build better time machines. These are not designed literally to travel to the distant past, of course, but to get a better look at it. The latest of these is the Planck Surveyor satellite.