Jillian's Guide to Black Holes: An informal introduction to black holes
This was originally written as a final project for PHY 312 at Syracuse University, but it has been re-written and upgraded many times since then. I wanted to create an introduction to black holes that is easy to read and more informal than a textbook. The information covered here is just the tip of the iceberg, an introduction to the wacky and wonderful world of relativity and astronomy. Amazingly, this site has been translated into Basque by Web Geek Science.
If you want to learn more about black holes, read up the references I used for this site. Those are some great books and websites. Also, check out George Greenstein's "Frozen Star: of Pulsars, Black Holes, and the Fate of Stars" (ISBN 0-88191-011-2). Mr. Greenstein's book is older, having been published in 1983, however his writing style is pleasant and his descriptions are still accurate. Another excellent book is "Black Holes and Time Warps: Einstein's Outrageous Legacy" by Kip S. Thorne (ISBN 0393312763), including a history of the physics of the past century.
There are also "hidden" pages that touch on topics which I felt necessary to describe in order to explain something about black holes. This includes topics like escape velocity, tidal forces, redshifting and blueshifting of light, lookback time and how telescopes are time machines, quantum tunneling, and spacetime diagrams. I link to these pages at various points in this site, but I thought I should list them all, here, in case you are interested. Also, regarding light cones, I was vague about what one sees as one falls into a black hole: I did not mention whether the viewer was accelerating or not. That whole bit about the universe condensing to a dot or to a circle depends on which observer you are. Acceleration makes a very big difference in relativity.
I have made all possible efforts to give credit where credit's due. Some of these pictures are mine and only the product of my imagination and Photoshop, but not all these pictures are mine. In each case I've made a link near the picture and explained where I found it. If, however, you find a picture that should have a reference cuz it's not mine, tell me and I'll be happy to change it.
If you like this webpage, or you have a question, or you just want to say you read it and think I'm insane, drop me an email. Don't be shy: comments, complaints, compliments, and corrections are all welcome at