All stars bright and beautiful,
All black holes great and small,
All spirals and ellipticals,
‘Twas gravity built them all.

Long-time readers no doubt already know this, but I love all black holes, great and small. Of the many topics I write about, I think black holes may be my favorite: they are laboratories for the most extreme gravity in the Universe, but also shapers of their host galaxies through the material they churn. Even though their reputation is that of a cosmic vacuum cleaner, they pump a lot of matter into the surrounding space; thanks to the light that material emits, black holes rank as some of the brightest objects in the Universe.

Quasars and blazars, ergospheres and event horizons: all of these things are topics in my upcoming CosmoAcademy class, “Introduction to Black Holes”. This online course begins next Tuesday, October 1, and runs for four 1-hour sessions. The class meets from 9  to 10 PM US Eastern time. Sign up today! No prior knowledge of black holes is required, and we’ll discuss the following subjects (though probably not in this particular order):

• What is a black hole? How gravity bends light, and extreme gravity can trap light
• The structure of a black hole: event horizons, ergospheres, and the “no-hair” theorem
• Observations of black holes: from Cygnus X-1 to supermassive black holes in galactic centers
• Active galactic nuclei: how black holes can become some of the brightest objects in the cosmos
• Role of black holes in shaping galaxies: accretion, jets, and feedback
• At the event horizon: black hole entropy, Hawking radiation, evaporation
• Other topics as we have time and interest!

Update: due to an error in the ticket price, this class was twice as expensive as it should have been. The correct price should be a lot more palatable!