What happened in the first trillionth of a trillionth of a trillionth of a second after the Big Bang? Super-sensitive microwave detectors, built at the National Institute of Standards and Technology (NIST), may soon help scientists find out. The new sensors, described today at the American Physical Society (APS) meeting in Denver, were made for a potentially ground-breaking experiment by a collaboration involving NIST, Princeton University, the University of Colorado at Boulder, and the University of Chicago. Although NIST is best known for earthbound measurements, a long-standing project at NIST's Boulder campus plays a critical role in the study of the cosmic microwave background (CMB) - the faint afterglow of the Big Bang that still fills the universe. This project previously built superconducting amplifiers and cameras for CMB experiments at the South Pole, in balloon-borne observatories, and on the Atacama Plateau in Chile.