Gravity: Black holes merge and release 3 solar masses in energy

I found a cool post on Slashdot bringing news of detection of the fourth gravitational wave ever detected. It was interesting to see how they managed to detect it, but the takeaway for me was the source of the gravity wave. Two black holes merged and 3 solar masses were converted into pure energy in the process. And all that created a perturbation in the space-time continuum smaller than an atom.

I've been fascinated with gravity since I was in high school. I used to ditch class, but instead of going off campus, I'd go to the library. Once there, I'd find my favorite book at the time, "The New Gravitation", and study the equations therein.

From there, I learned how to calculate orbital periods. So I made up a scenario. I imagined floating in a space station. I wondered what was the densest metal, and found with a little research in books, that it was Osmium. We didn't have the internet then. I had to look in a card catalog for a book on the periodic table, find something about elemental density in that book and then determine which element was the densest.

Then I calculated the mass of a ball of Osmium one meter in diameter. Then I imagined a smaller object to be set in orbit around it. Something the size of a bb or a small ball bearing. In my mind, I set that second body in orbit one meter from the surface around the Osmium ball. I remember playing with the variables to get something like several hundred days for an orbital period with my scientific calculator. I still have that calculator, but the battery is long dead and I can't open the battery compartment to replace it. Here it is:

I just never forgot how all that worked. I loved thinking about the concept of local gravity, and how there are slight variations in gravity based on my location on the planet. I was also fascinated with the idea that stars are caused by gravity, that's the force, the weakest force mind you, where stars get their ignition. A star is an accumulation of hydrogen that is so dense that atoms start to fuse to create helium.

But the black hole, and their cousin, the neutron star are even more interesting. Black holes have gravity so intense that not even light can escape. Neutron stars are so dense that all particles are merged into neutrons.

So I'm still thinking about how 3 solar masses were converted into pure energy during that merger of two black holes. That energy traveled 1.8 billion light years before our detectors noticed it. I'm pretty sure that anything within a few thousand light years of that blast was toasted on one side. I'm just glad we lived to record it and talk about it later.