Just a few months ago, scientists detected the crash heard round the universe, literally. For the first time, gravitational waves have been detected. Not only does this mean that a major piece of evidence to prove the last part of Einstein's' Theory of Relativity has been found, but it also adds another dimension to astronomy. On September 14, scientists at LIGO recorded the sound of two black holes colliding with each other.
If you're anything like me, you felt the excitement but also had a few questions. The first of which was probably something along the lines of, "What are gravitational waves again?" Never fear, the LIGO scientists are more than willing to share their knowledge, and excitement, with anyone interested. However, after spending all hours wading through scientific terms I found myself explaining things a little like this:
Even if you don't fully understand the weight of the discovery, it doesn't mean you can't take part in all the excitement, but it certainty helps. First, lets start with the basics. To really understand the importance, we have to understand what's been discovered. Basically, LIGO has discovered that the last component of Einstein's equation for space-time is real.
If you don't happen to have a functioning understanding of quantum physics, never fear. Lucky for us, Einstein was attributed to saying, "If you can't explain it simply, you don't understand it well enough," and many took this to heart. You probably learned a simplified version of The Theory of Relativity in elementary school. One part that had already been proven was the idea that gravity and inertia feel the same. A common example is when you ride one of the carnival rides that spin and push you to the outside. It feels like gravity, but it really isn't.
The second part of the theory, that large objects can cause gravitational shifts in space-time, is what has just been proven. You probably remember the example, a marble rolled on a sheet will bend the sheet around it and a bowling ball will have a similar, but much larger, effect. Until now, this remained only a theory and LIGO gets the credit for solving this century-old problem.
This leads to another question: what's LIGO and how did they do it? While the answer to this one doesn't lie somewhere in our distant memories of middle school, it is just about as easy to understand when we break it up into parts.
LIGO stands for Laser Interferometer Gravitational-Wave Observatory, and they have two stations, one in Washington and another in Louisiana. Their goal was to detect gravitational waves using their giant detectors, which they did successfully in September when they first reopened. This laser is extremely sensitive, much more powerful than the first one they built, which is how it could detect the black holes' collision from galaxies away.
This is such an important discovery that they waited about five months to release the information just to make sure this wasn't a false alarm. So what does this mean? For the first time we heard the universe. It's not believed that gravitational waves are very similar to sound waves, but this collision did register on a level frequency we could hear. Not only that, we also detected black holes colliding, which before had only been theorized. With Einstein's theory fully confirmed, we can ensure ourselves that the way we've been thinking of the universe for the past century was right, which is a relief to physicists everywhere.
We may not know now exactly where this discovery will lead, but everyone knows it's something important. We now essentially have another sense to explore the universe with. We have yet to see all this vast universe has to offer, and now we can hear it as well.
