Science Matters →

Question Your World: What are Gravitational Waves?

gravitational waves
(Image: Getty Images)

The science world occasionally gets rocked by a large breakthrough or discovery. Recently there’s been a lot of buzz about gravitational waves, so let’s catch that wave and chat about this epic discovery. Let’s dig into the big question: What are gravitational waves? Listen to this Question Your World radio report produced by the Science Museum of Virginia to learn more.

All the way back in 1916, Albert Einstein first shared his thoughts on gravitational waves. The genius thinker and scientist had opened our eyes to the nature of the world that surrounds us. His work includes an explanation of space-time, the invisible fabric that the observable universe hangs out in. This ‘fabric’ is a malleable and dynamic setting for the ongoings of all things in the universe as far as we can tell.

When you have a large object it warps the shape of the fabric of space-time. A giant star, for example, would bend the fabric of space time just enough to keep it’s planets forever falling in towards the bottom of the dent made by the star. Imagine taking a sheet and pulling it tight with a few of your friends. Now place a bowling ball in the middle of the sheet. Obviously the weight of the ball will stretch the sheet once placed in the center. This bowling ball represents a star. Now, if you threw some marbles on to the sheet they would fall in on the slop created by the massive bowling ball. That is one way to consider how gravity works.

The item in question though is if its possible for waves to go flying through the sheet at any capacity? Einstein said this was possible but would be very difficult to observe. Well, he was right on both accounts. Regardless, his prediction was made long before we made tech upgrades to life like orbiting satellites, advanced computer algorithms, Tinder, and so on. Using the most cutting edge equipment scientists have been able to observe the brilliant scientist’s concept of gravitational waves.

Basically, when an insanely large cataclysmic event happens (like 2 black holes colliding) a set of waves would be sent out through space. Much like a ripple through the pond of space-time. In order to observe the quick ripple as it passes scientists used a gigantic facility in the United States. LIGO stands for Laser Interferometer Gravitational Wave Observatory for anyone that needs to know the full catchy name.

This is a pair of 2.5 mile long tracks in an L shape. From it’s common origin point a laser is shot out down the two long stretches. LIGO researchers have been observing the time it takes the laser to bounce back. If a gravitational wave were to pass through the Earth it would stretch a part of the track enough to where the lasers would return at slightly different times. That’s exactly what was recently observed marking a historic first for the science community.

Observations of gravitational waves now give us a clearer look at the natural world that surrounds us and adds another big chapter to science books around the world. A century after Einstein’s discussions on this phenomena, we finally have observed this remarkable part of the universe.