Exploring Black Holes: Part 3

Seeing the Invisible

Black holes are invisible, but astronomers have developed a lot of ways to see them through the matter that surrounds them

Part 3 of a four-part series on black holes. Part 1 can be found here, and Part 2 is here.

Pioneering radio astronomer and professional weirdo Grote Reber. While his discoveries shaped our understanding of astronomy, he rejected a lot of modern theories about the universe in favor of his own peculiar ideas. (His vocabulary extended further than Groot’s, though.) Photo: National Radio Astronomy Observatory

In 1937, a deeply weird engineer named Grote Reber built a telescope in the lot next to his mother’s house in Wheaton, Illinois. Home observatories aren’t unusual, but Reber’s project was the first telescope designed to look for radio waves from space, and he was only the second person in history to find them. Karl Jansky, the first radio astronomer, had accidentally discovered astronomical radio waves while working on shortwave radio communications.

But Reber set out deliberately to study the cosmos in radio light. He found that the center of the Milky Way emitted a lot of radio waves and discovered an intense radio source in the constellation Cygnus. By the 1950s, astronomers found many other radio galaxies (as they were creatively named) that emitted very powerful radio waves from small regions at the centers of those galaxies.