Robert McNees
The International Symposium on Gravitational Collapse and Other Topics in Relativistic Astrophysics met #OTD in 1963 to discuss recently discovered "quasi-stellar radio sources." But the meeting is best known for a surprising announcement about black holes.
Image: Physics Today
Robert McNees
The meeting is now known as the 1st Texas Symposium on Relativistic Astrophysics. It's an ongoing series of meetings on gravity, cosmology, and relativity that takes place in December of most years.
The emphasis that first year was on quasi-stellar radio sources, which had been identified a few years earlier. In February of 1963, Maarten Schmidt recognized the Balmer series in their spectra and concluded they were very far away and ultra-luminous.
Robert McNees
We now refer to these objects – active galactic nuclei powered by supermassive black holes – as "quasars." But that name wouldn't be used until 1964, when it was introduced by Hong-Yee Chiu in an article for Physics Today.
Robert McNees
But the most important development at the conference came when a young physicist named Roy Kerr presented his solution of the field equations of general relativity describing a rotating black hole.
This solution describes the exterior of essentially every black hole in the Universe.
Image 2: James, Tunzelmann, Franklin, and Thorne
Robert McNees
The meeting was focused on quasars, so Kerr's presentation prompted many in the audience to leave or ignore his talk. Their attention was elsewhere. Most of them didn't appreciate the [ahem] gravity of what they were seeing.
Achilles Papapetrou, a giant of the field, was furious when he saw his colleagues ignoring Kerr's announcement. He stood and demanded the crowd's attention, noting that he had tried and failed to solve the problem for 30 years. They were witnessing something important.
Robert McNees
Subrahmanyan Chandrasekhar would later say that realizing the Universe is full of "untold numbers" of black holes described by Kerr's elegant solution was "the most shattering experience" of his scientific career.
Robert McNees
It’s funny that attendees of the conference almost overlooked Kerr's talk. We now understand that quasars are powered by supermassive black holes at the centers of distant galaxies, and these black holes are precisely described by Kerr's marvelous solution.
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