News From LIGO


LIGO

The Laser Interferometer Gravitational-Wave Observatory (LIGO) has announced a second gravitational wave detection.  The first detection happened on Sept. 14, 2015 and was announced in February, 2016, and the second was detected on December 29th, 2016 and announced just today.  The reason for the long delay is that the data has to be very carefully processed and analyzed to extract the precise meaning and ensure that it is a real gravitational wave event.

Like the first, this event is thought to be the merger of 2 black holes, although this pair is significantly smaller than the first.  It was detected by both observatories, in Washington and Louisiana.  The event appears to about 1.4 billion light-years from Earth (and therefore actually happened 1.4 billion years ago).
The signal from LIGO for such events is interesting in that it is in the audio frequency range, so we can actually listen to the sound of 2 black holes merging: http://apod.nasa.gov/apod/ap160615.html
Gravitational waves are an entirely new way of seeing the universe.  Before LIGO we were able to detect only various frequencies of electro-magnetic radiation, including visible light.  While some events that produce gravitational waves might also produce electro-magnetic radiation, this is not always the case.  Furthermore, LIGO gives us much more information about the properties of some events.  So we are, quite literally, at the beginning of an entirely new era in astronomy, just as we were 400 years ago with the invention of the telescope.

About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.

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