Bob Moler's Ephemeris Blog

Ephemeris for Monday, February 22nd.  The Sun will rise at 7:32.  It’ll be up for 10 hours and 47 minutes, setting at 6:20.   The Moon, at full today, will rise at 6:32 this evening.

On February 11th the LIGO team announced the discovery of gravitational waves coming from two black holes merging over a billion light years away.  LIGO stands for Laser Interferometry Gravitational-wave Observatory.  Two interferometers, one in the state of Washington, and the other in Louisiana detected the same signal milliseconds apart.  An interferometer sends a split light beam onto two paths 90 degrees apart to strike mirrors and return to interfere with itself.  A minute change in the length either light path will show up as a change in the interference.  The maximum change was one-one thousandths of the diameter of the proton subatomic particle.  This is a greater discovery than the Higgs Boson of a few years ago.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

A view of the LIGO detector near Livingston, LA. Credit LIGO.org.

The chirp heard ’round the world and indeed the universe. Credit: LIGO/Abbot et al. 2016. Hat tip: Phil Plait, the Bad Astronomer.