Sunday, February 14, 2016

LIGO first detection of gravitational waves

Some days ago LIGO (Laser Interferometry Gravitational waves Observatory) announced the detection of the first gravitational wave produced by the collapse of two black holes.
Here a nice summary of ideas behind the science and the experiment.

To understand how impressive this discovery is, here some "raw" numbers:
  • The interferometers making LIGO are huge: each arm of this L-shaped structures is 4 km long!
  • The "ripple" in the fabric of space-time that has been measured is TINY: 1/100000 of a nanometer, how much is this? It's the size of a atomic nucleus! This is incredible!
  • The ripple was produced by the collapse of two black holes, having 36 and 29 times the solar mass. The final black hole was 62 solar masses with 3 solar masses (36+29 - 62 = 3) "lost" in the ripples.
  • The collapse of the two black holes happened 1.3 billion years ago! 1.3 billion years!!!! The earth is about 4.5 billion years old!
  • The quest of the gravitational waves started over 40 years ago. 
  • The gravitational waves have been predicted by Albert Einstein in 1916!

Here you can listen Brian Green explaining Gravitational Waves to The Late Show with Stephen Colbert. Enjoy!

More info here:

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