A relatively rare event—an extra day in February, the every-four-years February 29th—greets us again this Monday. Why does this happen? As you might expect from my posing the question on this blog, the answer is wrapped up in astronomy. In…

A long time ago in a galaxy far, far away… Two black holes collided and merged, releasing unimaginable quantities of energy in the form of gravitational waves. Last year these waves were detected on Earth by an exquisitely sensitive pair…