Monster of the Milky Way

It is believed that a super massive black hole is at the center of our galaxy the Milky Way. There are some who speculate that there isn't, but of course I believe there is a massive black hole. Besides how dull is it to believe that there isn't one there? -Univer Soles-

Here is an interview by NOVA with astrophysicist Steven Ritz of NASA's Goddard Space Flight Center and the University of Maryland, and the second is Tom Lucas, producer of "Monster of the Milky Way." Will their conversation help you get a better fix on just what these mind-bendingly strange objects are? We hope so, but regardless we think you'll enjoy the ride.

Titled "Inside An Enigma"

Long read but I hope you enjoy and gain better insight on the subject of black holes.

An object, yet also a space
Q: So what is a black hole, Steve?

Steve Ritz: A black hole is one of the most interesting and unusual ideas in all of science. At its simplest, it is a region of space-time from which nothing, including light, can escape. Once something has fallen into or is within that region, it can no longer come outside.

Q: But what is it really? I don't get it.

Ritz: You mean how could that happen? Or what is it?

Q: I mean, is it a region? Is it an object? What is it?

Ritz: Right, right. Well, let me explain, and you tell me whether you think it is an object or not. You are familiar with the idea that what goes up must come down. Imagine I have a tennis ball and I throw it up. It is going to go up, slow down, turn around, and come back down. The reason for that is gravity due to the Earth. Now, if I throw that tennis ball really fast, at something like seven miles a second, it will not come back. It will be able to escape [Earth's gravity into space].
Now, imagine that we are on a more massive or more dense planet, so we are in a region where gravity is much stronger than we are used to here. You throw something up, it is clearly going to turn around and come back down, so you have to launch it faster [if you want it to escape]. Imagine continuing to increase the strength of the gravity in that region of space and time, and the speed at which you have to launch something just to escape approaches or even exceeds the speed of light. At that point the escape velocity will be larger than the speed of light, and that means that nothing can escape. That means anything within that region will always stay within that region; it is confined there.

Q: I thought light didn't have any mass.

Ritz: Right, but what I said was something had to move at a certain speed to get—

Q: But we are talking about gravity.

Ritz: Right, okay. Let's talk for a minute about our understanding of gravity, since Einstein's general relativity is really at the heart of all this.