Hilldale lecture draws noted astrophysicist with climate message

Noted astrophysicist Frank Shu will talk about reversing climate change when he visits the University of Wisconsin–Madison to deliver the Hilldale Lecture in the Physical Sciences.

Shu, professor emeritus of astronomy at the University of California campuses in Berkeley and San Diego, will speak at 6 p.m. on Oct. 12 in the H.F. DeLuca Forum in the Discovery Building, 330 N. Orchard St.

Shu has done pioneering research in astronomy on planetary disks, the origin of meteorites and the evolution of stars, among other things.

“He is a very creative scientist,” says Elena D’Onghia, a UW–Madison professor of astronomy. “Almost 50 years ago, he published seminal work on an explanation of the formation of spiral arms in galaxies, and now he is doing important work in climate change.”

Shu’s talk, “Reversing Climate Change Economically,” will address technology developed in his labs that he believes could halt the rise of atmospheric carbon dioxide: nuclear power from reactors fueled by thorium and cooled by molten salt, and using the molten salt to convert waste biomass into a carbon sink.

Abundant thorium can be used to make a uranium isotope suitable for nuclear fuel, but harder to weaponize, and Shu says molten salt cooling is safe and more flexible than plants that require ample water for cooling. He would use heat from the salt to bake waste biomass in the absence of oxygen to produce carbon-rich char that can be sequestered or used for agricultural or industrial processes.

At heart, it’s all physics, says D’Onghia, even if more of a terrestrial bent.

“Maybe it is an unusual shift. He is very eclectic. And he has the ability to turn his attention to new topics,” she says. “It makes him very special even for his abilities, and interesting for mathematicians and physicists and many fields beyond astronomy.”

The Hilldale Lecture Series, which began in 1973, is organized by faculty committees in four areas — arts and humanities, biological sciences, physical sciences and social studies.

All Hilldale lectures are supported by the university’s Hilldale Fund, and are free and open to the public. A reception follows the lecture.