Abstract

Black holes are the strangest prediction of Einstein’s Theory of General Relativity. The boundary around a black hole, known as the event horizon, is incredibly challenging to observe under normal conditions. However when a black hole consumes nearby material, it powers a system emitting partides and light. With a precise enough telescope, we can even see this as a ring of light surrounding a dark depression.

In 2017, the Event Horizon Telescope (EHT), a planet-sized array of radio telescopes, directly imaged this ring around two supermassive black holes. These iconic images mark both a culmination of a century of discovery and the beginning of a new chapter, with implications ranging from galaxy formation to the mystery of the highest energy particles detected on Earth.

In a talk mixing history, results, and personal anecdotes, I will convey the wonder of “seeing” the Universe in a new light, and sometimes with no light at all. I will also explore what lies on the horizon, as multi-messenger observations and advances in theoretical modelling converge on some of the deepest unsolved problems in physics.