If the sun were to wink out of existence, how long would it take for earth to be affected?
8 minutes. Light takes 8 minutes to reach earth and no signal of any kind can travel faster than light. Einstein's Special and General Theories of Relativity.
Yesterday a team of scientists from LIGO - the Laser Interferometer Gravitational-Wave Observatory - announced that they had detected gravity waves in September 2015.
This is exciting.
Seriously groundbreaking.
News of utmost importance in the science world. Gravity waves are fundamental to curved space, our expanding universe, and Einstein's General Theory of Relativity.
LIGO is a pair of X-Ray observatories almost 2,000 miles apart in Louisiana and Washington states. Each leg of the L measures 2.5 miles.
The speed-of-light time between them is 10 milliseconds. The L-shape and the difference in arrival times of the waves helps scientists determine the source of the wave detected.
In practice, LIGO was in operation from 2000 to 2010 with no results so it was shut down for refitting. With the new detectors, lasers are fired down the tunnels and reflected back to a central sensor that is tuned to detect a length difference in the tunnels. Interferometer sensors can detect a gravity wave near the size of a proton - but only one ten thousandth the size of that proton. Crazy small.
September, 2015.
The new detectors had barely come online when the gravity wave signal came through. 7 milliseconds separated the signals to the two observatories and scientists in the know were astounded.
HUSH HUSH until yesterday. They had to work out the details and make sure they were right. Nobody wants an early announcement that turns out to be a mistake.
- They confirmed the existence of binary black holes.
- The black holes were so supermassive that we still have to figure out how they formed.
- The black holes revolving around each other collapsed into one black hole.
- The energy from this collapse was MONSTROUS
From the NYT article yesterday.
"One of them was 36 times as massive as the sun, the other 29. As they approached the end, at half the speed of light, they were circling each other 250 times a second.
And then the ringing stopped as the two holes coalesced into a single black hole, a trapdoor in space with the equivalent mass of 62 suns. All in a fifth of a second, Earth time.
Dr. Weiss said you could reproduce the chirp by running your fingernails across the keys of a piano from the low end to middle C.
Lost in the transformation was three solar masses’ worth of energy, vaporized into gravitational waves in an unseen and barely felt apocalypse. As visible light, that energy would be equivalent to the brightness of a billion trillion suns.
And yet it moved the LIGO mirrors only four one-thousandths of the diameter of a proton."
How long ago did Einstein predict the existence of gravity waves? ONE HUNDRED YEARS. It took us a while.
All this gravity happened over A BILLION YEARS AGO. Now it's more than a billion light years away.
New York Times
The Telegraph (UK)
No comments:
Post a Comment