Gnarly Gravitational Waves, Brah
‘Sup, dude? Looks like there is a sick swell of gravitational waves coming in. But what does this righteous wave event even mean? Here are some steps so you can shred the information pipeline on gravitational waves.
Step 1: Definitions
To understand the discovery we have to meet the team involved.
Mass - How much stuff is in something. It is not size dependent. For example, two balloons of the same size could have different masses if one is filled with air and the other water.
Black Holes - A place where the pull of gravity is so intense, that nothing can get out, including light. For instance, there are black holes that are only the size of an atom, but have the mass of a mountain. Wowza!
Spacetime - A way of thinking about the universe that combines the idea of space (3-dimensions) and time.
Step 2: What are gravitational waves?
Imagine a bed sheet.
No, not like that.
But rather a sheet pulled tight on a hula hoop. You drop something in the middle. It would cause the entire sheet to be pulled with it.
And if you place something else in that sheet, it will move toward the big thing. Like your penny at the mall.
That is essentially what happens with a black hole. In this case, the sheet is spacetime, the cube is a black hole, and the marble is a planet. When the marble gets close to the cube, the cube sort of does a small shimmy. The shimmy that moves the whole fabric is what a gravitational wave looks like. But it’s pretty small when we are talking about marbles and cubes. This discovery was found when looking at two black holes that merged 1.3 billion years ago. Despite being approximately 30 miles (50 kilometers) across, they both had the masses of around 30 suns!
The red lights and jello jiggle are the gravitational waves coming from the two black holes merging.
Step 3: How did they do it?
Gravitational waves don’t make noise, but milliseconds before the two merged, the gravitational waves rolled out at a frequency we can detect. After traveling for billions of years, the waves hit earth.
The image has been dramatized. In actuality, the movement detected was smaller than a proton. LIGO, Laster Interferometer Gravitational-Wave Observatory, sends out a laser beam in two different directions. If the beams return the same length, that means no wave. But, when a gravitational wave passes through one of the beams, the beam will change length. Imagine you are racing a friend by swimming toward the beach in the ocean. If you have to swim over a big wave, you will have gone a further distance than your friend who didn’t.
Step 4: What’s the point?
Basically, this proves Einstein was right all those years ago. But more than that, we now have solid evidence of black holes and of gravitational waves. Now astronomers can use gravitational waves to make sense of everything from cosmic events to the Big Bang to the fundamental laws of the universe! It’s the equivalent of a deaf person hearing for the first time.
So get amped for the barrel of information coming your way. Cowabunga!