Einstein’s “Gravitational Wave” Discovery Revisited

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One hundred years later and Einstein’s controversial theory regarding the existence of gravitation was proven by scientists at the Laser Interferometer Gravitational Wave Observatory (LIGO).

Einstein's "Gravitational Wave" Discovery Revisited
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Einstein’s 100 years and last month’s proof

The collision of a two black holes 1.3 billion years ago, sent gravitational waves out through the universe, the same waves that Einstein theorized the existence of 100 years prior in 1916. These gravitational waves, or ripples, were finally confirmed last month by members of the Laser Interferometer Gravitational Wave Observatory (LIGO) team. Within 20 years of Einstein’s publication of his theory, he had largely convinced the scientific community of their existence but proof remained elusive for another 80 years. And to think that Einstein once went on record as saying that gravitational waves didn’t exist, before changing his mind….and then changing it again.

Albert Einstein didn’t have the luxuries of the LIGO technology but rather just a pencil and a piece of paper to work out the numerous equations necessary to prove that the acceleration of objects caused disruptions in the space-time surface when the waves are sent out throughout the universe at the speed of light.

Using two detectors located in Livingston, Louisiana, and Hanford, Washington, the Laser Interferometer Gravitational Wave Observatory (LIGO) began looking for gravitational waves in 2000. However, while the waves were certainly there, the instrumentation of LIGO in its first use wasn’t nearly sensitive enough to find them. However, after a new round of funding was made available to researchers, LIGO was upgraded a number of times between 2010 and 2015. Those upgrades included a method by which the detectors were mounted in order to isolate them from ground vibrations as well as getting a host of more powerful lasers installed.

The LIGO upgrade paid off in February

Those upgrades paid off in spades when September 14, 2015 came around and the system was back on line to detect “loud” chirping noises from both of the aforementioned detectors. The LIGO detectors are designed to use an L-shaped antenna with two arms with each measuring over two-and-a-half miles in length. Ultra-pure glass mirrors are installed on the end of each arm and they are kept isolated from both outside light and more importantly any vibrations. Near the point of confluence between the two arms, a laser beam is sent out to each mirror. LIGO has no interest in the beams cancelling each other out when they are the same length, but, and this is the important bit, if there is a gravitational wave passing between them one arm will be compressed while the other is stretch. This creates a tiny, I mean really tiny (not even a proton in width), disturbance that indicated the existence of gravitational waves.

I skipped a step, that flicker of light caused by the stretching and compression of the antennas is turned into sound waves that chirp and told the scientists that they had finally worked out the detection of gravitational waves. While the team knew that it had detected gravitational waves for the first time, they wanted to be sure and once confirmation was achieved the scientists were willing to tell the world a month ago today.

Imagine a black hole nearly 30 times the size of our sun and another over 36 the size of the sun colliding together. This happened nearly 1.4 billion years ago and the sheer magnitude of the collision created the burst of energy that is still being detected today.

LIGO team member Rainer Weiss, an emeritus professor of physics at the Massachusetts Institute of Technology was the man who first devised the detection equipment necessary for LIGO over three decades ago.

“The description of this observation is beautifully described in the Einstein theory of general relativity formulated 100 years ago,” Weiss said in a February statement that was peppered with praise for young Einstein. “It would have been wonderful to watch Einstein’s face had we been able to tell him.”

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