This image shows one of the NASA detectors from the BICEP2 project, developed in collaboration with the National Science Foundation. The sensors were used to make the first detection of gravitational waves in the ancient background light from the early universe. The discovery provides the strongest evidence yet for an explosive period of expansion in our universe known as inflation.
The detectors were developed and built at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.
The image was taken by a “scanning electron beam” microscope, giving a close-up, 3-D view. The detector works by converting the light from the cosmic microwave background — relic radiation from the Big Bang — into heat. This heat is dissipated on a meandering gold film located on an island of material suspended in free space by tiny legs that were made by a process called micro-machining. (The island is the rectangle suspended in the black free space.) A superconducting titanium film on the detector (left side of island) serves as a sensitive thermometer to measure this heat.
The sensors are cooled to just 0.25 degrees above absolute zero to minimize thermal noise. The island is designed to further increase the sensitivity to heat by isolating the thermometer from the rest of the structure.
Scientific American also reports:
Physicists have found a long-predicted twist in light from the big bang that represents the first image of ripples in the universe called gravitational waves, researchers announced today. The finding is direct proof of the theory of inflation, the idea that the universe expanded extremely quickly in the first fraction of a nanosecond after it was born. What’s more, the signal is coming through much more strongly than expected, ruling out a large class of inflation models and potentially pointing the way toward new theories of physics, experts say.
“This is huge,” says Marc Kamionkowski, professor of physics and astronomy at Johns Hopkins University, who was not involved in the discovery but who predicted back in 1997 how these gravitational wave imprints could be found. “It’s not every day that you wake up and find out something completely new about the early universe. To me this is as Nobel Prize–worthy as it gets.”