From symmetry Explain it in 60 seconds: Cosmic inflation Cosmic inflation refers to a period of rapid, accelerated expansion that scientists think took place about 14 billion years ago. Our universe has likely never grown as quickly as it did during that period. Faster than the blink of an eye, the whole universe expanded so that an area the size of an atom was suddenly the size of a grapefruit. Scientists think this expansion was driven by the potential energy of the inflaton field, a new field that turned on just after the big bang. Support for the theory of cosmic inflation comes from the Cosmic Microwave Background, or CMB, a pattern of light released when the early universe first cooled enough for particles to travel freely through it. Although nearly uniform, the CMB contains ripples. Scientists think these were caused by tiny quantum fluctuations that were amplified to huge scales by cosmic inflation. Scientists study cosmic inflation through experiments at telescopes, such as the Planck satellite and BICEP2 at the South Pole. These experiments measure elements of the CMB, looking for the footprints of inflation. When inflation ended, the expansion of our universe began to slow down. But then another influence took over, pushing it back to an accelerating rate. This influence is thought to be dark energy. —Rhianna Wisniewski Read similar explanations in the symmetry archive. Photos of the Day Autumnal beauty In the News Dwarf galaxies dim hope of dark matter From Quanta Magazine, Oct. 25, 2014 Once again, a shadow of a signal that scientists hoped would amplify into conclusive evidence of dark matter has instead flatlined, repeating a maddening refrain in the search for the invisible, omnipresent particles. The Fermi Large Area Telescope (LAT) failed to detect the glow of gamma rays emitted by annihilating dark matter in miniature "dwarf" galaxies that orbit the Milky Way, scientists reported Friday at a meeting in Nagoya, Japan. The hint of such a glow showed up in a Fermi analysis last year, but the statistical bump disappeared as more data accumulated. Read more In the News Who really found the Higgs boson From Nautilus, Oct. 23, 2014 To those who say that there is no room for genius in modern science because everything has been discovered, Fabiola Gianotti has a sharp reply. "No, not at all," says the former spokesperson of the ATLAS Experiment, the largest particle detector at the Large Hadron Collider at CERN. "Until the fourth of July, 2012 we had no proof that nature allows for elementary scalar fields. So there is a lot of space for genius." She is referring to the discovery of the Higgs boson two years ago — potentially one of the most important advances in physics in the past half century. It is a manifestation of the eponymous field that permeates all of space, and completes the standard model of physics: a sort of baseline description for the existence and behavior of essentially everything there is. By any standards, it is an epochal, genius achievement. What is less clear is who, exactly, the genius is. Read more