For the third time in less than two years, physicists have
detected billion-year-old ripples in the fabric of space-time. The
new recording, like the two others before it, was made using the
Laser Interferometer Gravitational-Wave Observatory (LIGO)...
Could dark matter consist of primordial black holes, as numerous
as the stars? It’s an old, improbable idea, but it made a
Lazarus-like comeback a year ago, when the discovery of
gravitational waves suggested that the cosmos abounds with...