Gravitational Waves

I learned this week about the most important recent development that has happened in Physics. The Laser Interferometer Gravitational-Wave Observatories (comprised of two separate facilities 1800 miles apart) detected gravitational waves. This detection is so important because it is the first proof of the existence of these waves that was predicted by Einstein’s relativity theory 100 years ago.

Now where did these waves come from? A cursory understanding of Einstein’s theory of relativity reveals that space-time is “bent” in a sense by objects of mass. Think of the effect of a bowling ball on a bed. The greater the mass, the greater the bend. Black holes are objects of such great mass in such a small area, that they create as extreme a bend as is physically possible. Now, consider what the effects might be if two objects of that mass smashed into each other near the speed of light. This is what caused the gravitational waves that were detected.

To really appreciate this, think about the effects of two bowling balls crashing into each other at 100 mph. They’d both turn into dust. How about two cars crashing head on at 300 mph? They would be pulverized into nothingness. How about two FULL EARTHS crashing at 1 million mph? This doesn’t even scratch the surface of the collision that was detected by LIGO. That collision involved two objects with the mass of 30 suns (yes, 30 full suns, one of which is 400, 000 times the mass of the earth) where all that mass is contained within a 100-mile radius (1 single sun has a 400, 000 mile radius). Those two black holes collided at about 500000000 mph – a little faster than your average car can go – and combined with each other. This collision was so extreme that it caused ripples in space-time, the ripples that were detected by LIGO and predicted by Einstein.

This discovery first of all confirms that black holes exist, and begins another revolutionary chapter in the advancement of physics. Detecting these waves will likely become commonplace, and we will be able to further our connection to and understanding of events happening in the billions and billions of lightyears of space surrounding our puny little planet Earth.