I'm back

To skip the astronomy tidbit, scroll down to the next paragraph.

At the center of the earth, there is a tiny spherical region of space which is rather special. It is theoretically impossible to know about anything that happens inside of this region. Allow me to explain. Cosmic bodies (and, technically, all matter) have escape speeds, i.e. the speed one must travel in order to escape the gravity of the body at the surface. The escape speed on earth (at a 6400 km radius) is just over 11 km/s. Escape speed is proportional to a planet's mass and inversely proportional to the square of the distance you are from its center. So if you were to take a planet and compress it so that you retain all of its mass but decrease the radius, you can increase the surface escape speed. Now imagine if you can keep compressing the planet until you raise the escape speed to the theoretical maximum of speed: c, the speed of light (300,000 km/s). This means that in order to leave the surface of a planet with a radius any smaller than this, you would be required to travel faster than the speed of light, which is impossible. The surface of this little sphere would represent an imaginary border called an event horizon because any event that is occurring within this radius can ever be seen, heard, or known by anyone outside--even light does not escape. The radius of this imaginary sphere is called the Schwarzschild radius. The Schwarzschild radius of the earth is about a centimeter. So even if we could hypothetically travel to the center of the earth, there would be this little region the size of a grape that we could never know about.
Another thing: there are actual objects whose entire mass lies inside their Schwarzschild radius, meaning that it is impossible to get any information from these objects at all. They are called black holes.
If you thought that was intriguing, you should read about special relativity.


So. We are like halfway through this semester and I am in that annoying period of time where I should really start studying for exams but I really don't want to because they are sort of far away. So, I content myself with catching up on episodes of The Big Bang Theory.
In other news, Nipunn came to visit yesterday! CMU had an ultimate frisbee tournament here so he arrived here with his team yesterday afternoon. When I first saw him late last night, he was caked in mud. After he showered, we took him for Rahul's place to hang out and D.P. Dough's for a killer calzone.

Oh, and I may be in love with Counter Strike Source. I don't know when this happened. But it's bad and I love it.