Black holes are gravity at the extreme. As such, many of their properties lie at the edge of our knowledge of physics. At the event horizon — the boundary beyond which nothing can return to the outside Universe — we must grapple with the combination of gravity and quantum physics, a problem we have yet to solve. And inside the event horizon gravity is even stronger, where general relativity predicts an infinitely dense concentration of mass.

In my next CosmoAcademy class, we will take a deeper look at black holes than you’d likely get from most other online courses. Among the topics we’ll discuss:

• The “no-hair theorem”: black holes are described wholly by mass, spin, and electric charge
• Black hole thermodynamics: the temperature and entropy of black holes
• Hawking radiation: how black holes can evaporate
• The “information paradox”: when something falls into a black hole, its identity is lost, so what happens when the black hole evaporates?
• The “firewall paradox”: does Hawking radiation produce a hot barrier at the event horizon, flash-frying anything that crosses?
• The holographic principle: the entropy of a black hole depends on its surface area (which is a two-dimensional property), but the size of a black hole is three-dimensional

The class starts in two weeks, so sign up today! No prior knowledge of black holes, gravity, or quantum physics is needed.