Lesson 5 — How We Observe Black Holes

Understanding the Complex: Black Holes — What Really Happens When Space Ends

---

Anchor continued: Sgr A — 26,000 light-years away, completely invisible to optical telescopes.*

Black holes emit no light. They're defined by the fact that light can't escape them. So how do we observe something that, by definition, is invisible?

Three methods. Each reveals something different.

---