Black Holes- Really Kind of Suckish

Another bad pun.
Welcome back, hypothetical reader. Its been a while.
Well, last time you were here, I discussed quasars, their properties, and how they interact with objects around them. In addition, I briefly mentioned black holes, namely that quasars form around them in young galaxies. I also said that I'd go further into depth about the qualities of black holes. Were you looking forward to this? Of course you were!
"What is a black hole?"
A black hole could be called either a region or an object, depending on how you look at it- yes, technically it is a super-massive object, but we are ultimately more interested in the region around this object than the object itself. If you're reading this blog, it's pretty safe to assume you're in my astronomy class, but I'll start at the beginning anyway.
Isn't gravity great? It makes so many things possible- baseball, pouring drinks, not hurtling off into space, being able to exist in general- little things. We take it for granted, but when it gets strong enough, weird things start to happen. Our Earth is pretty massive, at 5.9736*10^24 kg. The escape velocity for earth is 11.2 km/s. Black holes, on the other, are so absurdly massive that their escape velocity exceeds the speed of light, making it impossible for anything to escape their gravity an object comes close enough.
You could also look at this another way. Instead of looking at the gravity of this object, you can instead look at the distortion of space-time, which is, in essence, what gravity is anyway. Either way you look at it, there comes a point where something comes so close the the center of the black hole, or "singularity," that it can't possibly get further away again. This can be viewed as a ring (or sphere, if you prefer to think in three dimensions) with the singularity at the center. This ring is referred to as the "event horizon" or "Schwarzschild radius," and is defined as the distance from the singularity where the escape velocity is equal to the speed of light.Once this radius is crossed, the escape velocity is greater than the speed of light and is, as far as we know, inescapable. Here's why:
Take the equation
1/2mv^2=GmM/r^2
Where m is the mass of an escaping object, and v is the velocity required to escape. When you solve for v, you get
v=(2GM/r)^1/2
From this, you can see that if an object is massive enough, and you are close enough to it, it is entirely possible for v, the escape velocity, to exceed the speed of light.

That's all for today, I will continue talking about black holes in tomorrow's post, including a look at the process for discovering black holes, and probably an example of a black hole in our or a neighboring galaxy.
Until next time, happy astronomy.

Sources-
Wikipedia articles for Black holes, the earth, and escape velocities
The black holes faq on the Berkley.edu site by Ted Bunn- http://cosmology.berkeley.edu/Education/BHfaq.html#q1

Quasar Sources

Sorry, I forgot to post my sources in my quasar research post.
I got most of my information from either the quasars article on Wikipedia, or a quasar faq on the Virginia Tech website, which was compiled by a Dr. John Simonetti. The included image is credited to the European Southern Observatory for the image, thought the artist for the image was unlisted.