It's a kind of Magic:

From illusion to knowledge

Inaugural Lecture held by Prof. dr. Mariano Méndez

at the University of Groningen on March 15 2016

Follow the link to get a PDF version of the booklet

Here is the PDF of the slides of the class (with presenter's notes)

And here is a video of the class (via Facebook) taken with a fixed camera at the back of the room (it does not show the slides during the class).
(Click here to see it directly via Youtube if you do not have Facebook.)

SUMMARY:

Imagine I told you that I have an investment opportunity that will pay you back 1100% of the amount you invest per year. Yes, you read correctly: one thousand one hundred percent per year; compare that with less than 1% you get from saving accounts nowadays. I would also tell you that this is an extremely low-risk investment: It has been paying about the same rate every year for, at least, the last 50 years. I bet you would tell me: "Wait a minute, what's the catch?" And would you still trust me if I told you that the story involves a Nigerian, Dr. Romanus Eze, son of the late...? "Okay, wait a minute." you would interrupt me "I know this scam. And in the end you are only an astronomer. What do you know about investments?"

Fine; let me then talk to you first about what I am supposed to know, and come back to this investment story later on. Here I go: Because no radiation can escape from them, we may never be able to observe a black hole directly; yet black holes "radiate" an appeal that continues to captivate scientists and laypersons alike. This is a complex topic, but I will try and explain some interesting, yet relatively simple, ideas that will help the audience understand, at least in a generic way, what a black hole is.

You may now think: "Huh, this guy is weird; what he wrote makes no sense. One thing has nothing to do with the other."

You may be right... or perhaps not. Let me explain...

Errata to the printed version of the same booklet

p.6: To give you an idea, you could go 25 thousand times around the Earth in 1 hour if you travelled at that speed.

p.16: However, social psychologists have shown that the more successful people are usually also less happy than the rest