100th Stargazing Lecture at Caltech Features Kip Thorne

About 1,000 Southern Californians listened as Nobel Laureate Kip Thorne (BS '62) reached across history, physics, and astronomy to highlight characters and discoveries that changed humanity's understanding of space and time.

Thorne's July 12 talk, "An Odyssey Through the Warped Side of Our Universe," marked the 100th in Caltech Astro's Stargazing Lecture Series. It was followed by a Q&A, a panel discussion, and guided stargazing. Thorne is Caltech's Richard P. Feynman Professor of Theoretical Physics, Emeritus, and an author and Hollywood science consultant.

He described the suspenseful international effort to understand and observe the warping of space and time. He joined the effort in the early 1960s and was involved for more than half of the century between Albert Einstein's 1915 prediction of the existence of gravitational waves and 2015, when these ripples in space and time were first detected. That famous observation came from LIGO, or the Laser Interferometer Gravitational-wave Observatory, which Thorne co-founded with Rai (Rainer) Weiss of MIT and Barry Barish, Caltech's Ronald and Maxine Linde Professor of Physics, Emeritus.

Thorne's talk surveyed phenomena that warp space and time including black holes, wormholes, gravitational waves, and the Big Bang. He also described vacuum fluctuations, which he has rarely spoken about, though they fascinate him. After wrapping up the talk with a few comments on the potential for time travel, he took questions from the audience.

Then the evening's emcee, Cameron Hummels, who is an astrophysicist and director of astrophysics outreach at Caltech, gave the audience some choices. As at all Stargazing Lectures, guests could go outside to stargaze, stay inside for a panel discussion, or sample both options.

On Beckman Mall, Caltech graduate students and postdoctoral scholars helped audience members observe the sky through six telescopes. Through scattered clouds, visitors glimpsed the Hercules Cluster, the Ring Nebula, the Whirlpool Galaxy, and the waxing crescent moon.

Inside, the panel discussion featured Thorne, Hummels, and two relatively new members of Caltech's faculty: Katerina Chatziioannou, assistant professor of physics and a William H. Hurt Scholar, and Elias Most, assistant professor of theoretical astrophysics.

Audience questions reflected the evening's soaring curiosity. For example, could something like the warp drive seen in Star Trek be feasible? What might be inside a black hole? Did Thorne believe from the first that LIGO would work? About that, Thorne said, "When Rai [Weiss] proposed this particular technique and I looked at it, I didn't think it had a prayer of a chance. He claimed that you could make measurements 10 million times better than the technology of that era could do. The leap—the distance you had to go—was so big. It was only after three years of looking at this and conversations with great experimenters… that I came around and thought we had better than a 50/50 chance of success."

Valuable advice arose from a question about what research topics the panelists would pursue if they were starting out now. Thorne said to find something that you love, because the work will be hard, and to favor modes of work that suit your personality. Chatziioannou said to choose something that excites you and find colleagues you enjoy, since you will spend so much time with them. Most noted that you don't have to choose what you will do right at the start, revealing that he tried out many options and almost went into finance. Hummels agreed about keeping an open mind but threw in a pitch for exoplanet science, a timely pursuit that could lead to the discovery of life far beyond Earth.

For those who missed it, Thorne's lecture and the ensuing panel, like all events in the series, is available to watch on the Caltech Astro YouTube Channel.