Some quick links about the measurement, announced today, by the BICEP2 collaboration using a telescope at the South Pole equipped with transition edge sensors (TESs) read out with superconducting quantum interference devices (SQUIDs), of B-modes (or "curl") in the polarization of the cosmic microwave background (CMB) radiation, considered to be an imprint on the CMB of primordial graviational waves stirred up by the period of rapid expansion of the universe (probably from around 10-35--10-33 sec). BICEP2 estimates the tensor-to-scalar ratio "r", an important parameter constraining models of inflation, to be 0.2 (+0.7 / -0.5).
Note that I'm not at all expert on any aspect of this!
Instrument paper: BICEP2 II: Experiment and three-year data set
Good background blog post (semi-popular level) from Sean Carroll
Carroll's initial reaction.
Richard Easther on inflation, also anticipating the discover (also fairlybroadly accessible)
Very interesting reaction from a particle physicist at Résonaances.
Reaction from Liam McAllister guesting on Lubos Motl's blog.
NIST Quantum Sensors project homepage.
Besides a microwave telescope to collect and focus the relevant radiation, the experiment used transition-edge sensors (in which photons can trigger a quantum phase transition) read out by superconducting quantum interference devices (SQUIDs). I don't know the details of how that works, but TE sensors have lots of applications (including in quantum cryptography), as do SQUIDs; I'm looking forward to learning more about this one.