– Daniel Holz, professor in Physics, Astronomy, and Astrophysics at the University of Chicago, the Enrico Fermi Institute, and the Kavli Institute for Cosmological Physics; Chair of the Science and Security Board of the Bulletin of the Atomic Scientists; and founding director of UChicago’s Existential Risk Laboratory (XLab).

Daniel Holz studies black holes, gravitational waves, and cosmology, all while also running the Existential Risk Laboratory at the University of Chicago. In this episode, Daniel helps us shed light on some of the biggest threats facing humanity—the kind that could really do us all in. On Daniel’s list: a flat-out nuclear war erupts, climate change worsens, biological warfare and bioterrorism, the possibility that the chaos of misinformation could make good governance impossible, and that artificial intelligence might decide we humans are too irrational and inefficient to keep around. (Along with some other cheery topics.)

Daniel also is part of the group that set the hands of the Doomsday Clock, which signifies how close (or how far away) we are from the end of life as we know it. (He chairs the group, officially called the Science and Security Board of the Bulletin of the Atomic Scientists.) Right now, the clock reads 89 seconds to midnight. That’s the closest we’ve ever been to a global catastrophe.

In Daniel’s life as an astrophysicist, he’s one of the collaborators in the  Laser Interferometer Gravitational-Wave Observatory (LIGO), which works on the cutting edge of gravitational wave physics. Gravitational waves are ripples in the fabric of spacetime, triggered by cataclysmic cosmic events like the collision of black holes or neutron stars. LIGO uses incredibly sensitive laser interferometers—tools that measure tiny changes in light—to detect gravitational waves. It’s a big leap beyond what traditional telescopes can do, opening up to us lowly humans an entirely new way to observe the universe. You can read more about LIGO’s impact here. 

UChicago’s Existential Risk Laboratory (XLab) is a lab that uses risk analysis and research to study some of the world’s most significant threats. The idea for the lab came from a class Daniel co-taught with James Evans, a computational scientist and sociologist, called “Are We Doomed”? The class caught the attention of Rivka Galchen, a staff writer for The New Yorker. Subsequently, her article in the magazine caught Jill’s attention. Jill’s been interested in the topic since reading Tony Ord’s book The Precipice.

The XLab’s purpose is to study existential threats so that people can be made more aware of them, and hopefully, so we humans can figure out how to prevent them from occurring. The XLab provides a venue for UChicago students to build expertise in the focus areas of concern.

When recording the episode, Jill asked Daniel to describe what it was like to be in the committee meetings when its members decide what position the hands of The Doomsday Clock should be set at. Daniel’s response and their conversation about it didn’t make it into the final cut of the episode, but you can listen to that outtake here. 

The Doomsday Clock is a device that alerts the public to how near we humans truly are to destroying the world with technologies of our own making. The Doomsday Clock is a metaphor, a reminder of the perils of existential catastrophe. If the hands were ever to reach the position of “midnight,” that would mean the end of civilization.

Created in 1947, the symbolic clock was started by the Bulletin of the Atomic Scientists. Many founding members of the Bulletin were scientists from the Manhattan Project at the University of Chicago. (The same university where Daniel now teaches.) The scientists who helped to split the atom understood full well that the presence of atomic weapons threatened life on Earth like nothing else that had ever existed before. 

Since 2008, the Science and Security Board, which Daniel chairs, is part of the Bulletin, and this is the group of scientists and other experts who determine the setting of the hands.  Twice a year, they meet. As of this writing, the clock hands are set at 89 seconds before midnight. This is the closest to midnight that they’ve ever been at any point in history.