A Black Hole by any Other Name

1967: John Archibald Wheeler

John Archibald Wheeler was one of the most accomplished physicists of the 20th century. He helped develop the theory of nuclear fission and made key contributions to Einstein's theory of gravity and the shadowy realm of quantum mechanics. When he died in 2008, however, the lead paragraph in almost every newspaper and magazine story focused on one relatively minor accomplishment: He coined the term "black hole."

Wheeler in the 1980s

Wheeler had studied under famed Danish physicist Neils Bohr, and in the late '30s they developed the theory of nuclear fission that later led to the development of the atomic bomb. Wheeler worked on the bomb and, after World War II, on the new hydrogen bomb, before turning to the complex realm of Einstein's general relativity.

In 1939, J. Robert Oppenheimer, another atom-bomb pioneer, and a graduate student had calculated that a star of sufficient mass would collapse to such great density that nothing could escape its gravitational pull, including light.

Wheeler was intrigued by the conclusion, but he thought it was flawed because it did not consider the effects of nuclear reactions, heat, pressure, or anything else other than gravity. In 1958, in fact, he and Oppenheimer publicly argued over the conclusion because Wheeler believed that such a collapsed object would violate fundamental laws of physics.

By that time, however, other physicists were using both the computers and the numerical codes created to simulate the nuclear reactions and intense temperatures and pressures inside H-bomb explosions to revisit Oppenheimer's calculations. Their results were the same: At a certain point, gravity simply overpowers every other force in the universe.

And in 1958, physicist David Finkelstein described the "event horizon" surrounding a collapsed star as a one-way door through which objects could enter but never leave. The physics of any processes inside the horizon are forever shielded from prying eyes.

Wheeler slowly became convinced that dark "collapsed" stars could exist, and he began studying them fiercely, becoming one of the world's leading experts on the subject.

Yet neither the public nor most other physicists were paying much attention to the subject, in part because no one really knew what to call such bizarre objects. Names like "collapsed stars" and "Schwarzschild singularities" were bandied about, but created little enthusiasm.

So in late 1967, Wheeler introduced a new name, first at a conference in New York and later in a lecture to the American Association for the Advancement of Science: black hole.

"I decided to be casual about the term," Wheeler wrote in his 1998 autobiography, "dropping it into the lecture and the written version as if it were an old familiar friend. Would it catch on? Indeed it did. By now every schoolchild has heard the term. Richard Feynman, when he heard the term, chided me. In his mind, it was suggestive. He accused me of being naughty."

Naughty or nice, though, it stuck, earning John Wheeler a spot in the history books and giving the rest of us a catchy name for one of the most intriguing phenomena in the universe.