Get ready for another installment of Dr. Science’s Nobel Prizes! I mean, they’re not my prizes, but… anyway, much like your mother last night, these noble Nobel Prizes just keep on coming. The second prize announced this year is in physics, awarded to Rainer Weiss, Barry C. Barish, and Kip S. Thorne for the detection of gravitational waves.
So what, right? We all know about gravity, even that apple-on-the-head guy way back in 1700-whatever (side note: that didn’t exactly happen). Well, it’s a little more than that.
In 1916, along with the rest of his theory of general relativity, Albert Einstein (yeah, that one) predicted that gravitational force was a result of a bend in spacetime. Think of a marble rolling towards a sumo wrestler sitting in the middle of a trampoline: the marble moves toward the wrestler because the trampoline bends under his (or her! #feminism) weight. In Einstein’s model, gravity would move in waves, similar to radiation (light), as the result of large gravitational interactions (like the sumo wrestler jumping up and down on the trampoline, which would flex with the jumps). This contradicted the previously understood Newtonian model of gravity, which predicted instantaneous gravitational effects between objects. Now that you can see the marble and the trampoline, think of puppies riding around on a Roomba.
That has nothing to do with physics; I just felt like we all needed that this week.
Anyway, while Einstein’s theory worked with our understanding of space and time, it had been impossible to prove. In the 1970s, Rainer Weiss proposed a way that these gravitational waves could be detected by using a laser interferometer. This works by reflecting two lasers off mirrors, which are then beamed back to a meeting point. If the distances that the two lasers travel are identical, the waves should perfectly interfere with each other, and the interferometer will detect nothing at all. This is the principle behind your noise cancelling head phones, and how they save you from hearing that jackass in 5D for the entirety of a trans-Atlantic flight. However, if one distance is just SLIGHTLY off the other, the wavelengths will become garbled with each other, and instead of neatly cancelling out, a detectable interference pattern is produced.
In the ’80s, Weiss and Kip Thorne, along with a sadly now-deceased Ronald Drever, proposed building an interferometer large enough to detect these waves. Collaboration between Caltech, MIT, and eighty other research institutions brought the project, called the Laser Interferometer Gravitational Wave Observatory (LIGO) to fruition. Barry Barish (I would make fun of his name, but, you know; Nobel Prize) joined the project in the 1990s, and in 1997, became the director, leading LIGO completion. The collision of two black holes, each thirty times the mass of the sun, provided the gravitational event, which were detected in 2015. In 2016, one hundred years after Einstein proposed the theory, the physicists published a paper documenting the first observation of gravitational waves.
So, remember: if you want to win a Nobel, all you need to do is work for decades to determine the fundamental make-up of the universe. I would start now.
Sources:
https://www.nobelprize.org/nobel_prizes/physics/laureates/2017/press.html
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