Experimental studies of black holes: status and future prospects

Understand

More than a century ago, Albert Einstein presented his general theory of gravitation (GR) to the Prussian Academy of Sciences.

• One of the predictions of the theory is that not only particles and objects with mass, but also the quanta of light, photons, are tied to the curvature of space-time, and thus to gravity.
• There must be a critical compactness, above which photons cannot escape.
• These are black holes (henceforth BH).