You probably know the basics when it comes to black holes: A lot of mass squished into not a lot of volume makes for an entity so prodigiously dense, not even light can escape its gravity …

A research astronomer at NASA’s Jet Propulsion Laboratory, Grojian specializes in the structure of the universe .. and he’s good at explaining the stuff. Check out the video and  watch Gorjian discuss black holes at five scales of difficulty, from grade school to grad school right on up to fellow-black-hole-expert levels.

You will find the video at An Astronomer Explains Black Holes at 5 Levels of Difficulty, an article on Wired Magazine