https://www.scientificamerican.com/article/an-exit-chute-from-the-universe-the-story-of-a-historic-effort-to-image-a-black-hole/

The Event Horizon Telescope (EHT) has always sounded like an unlikely proposition: create a virtual Earth-size telescope to take a picture of the shadow of a black hole. Every piece of that sentence is a little bit insane.

But it worked. After more than a decade of technical development and fundraising and astronomer-herding and telescope-wrangling, the astronomers of the EHT unveiled the first picture of a black hole—a bubble of pure gravity, a hole in spacetime, a prediction of general relativity so strange that Albert Einstein himself long refused to believe the concept was possible.