Nobel laureate speaks about the future of Physics in Buhl Lecture

In a presentation called “The Future of Physics,” this year’s Buhl Lecture, Nobel laureate David Gross spoke about the 25 most important problems at the forefront of physics.

The Buhl Lecture is an annual event hosted by Carnegie Mellon. Each year, a prominent physicist is invited to the Mellon College of Science to deliver a lecture to the public concerning a topic of interest in current physics research.

David Gross is the Frederick W. Gluck professor of theoretical physics and director of the Kavli Institute for Theoretical Physics at the University of California, Santa Barbara.

In his presentation, Gross began with a short overview of the advancements in physics over the past 35 years. He noted that the rate at which human knowledge has advanced over this period of time has been nothing short of remarkable.

“The most important product of science is knowledge; however, the most important product of knowledge is ignorance,” Gross said, adding that “major advances in both theory and instrumentation have led us to realize the concept of ‘intelligent ignorance’: Namely, the more we learn, the more we find out we don’t know.”

Gross said that some of the most important questions in physics today lie in discovering the origin and composition of the universe — how scientists think the universe began, the properties of dark matter, dark energy, and how stars formed in the early universe.

“Where this was once a religious [and] philosophical debate, physicists are now attempting to answer it by using theories to run time backward. Even today, physicists struggle with the concept that time itself is emergent,” Gross said.

Gross also touched on the topic of physical theories, including quantum mechanics and a physical theory of biology.

Speaking of quantum mechanics, he said, “Opinions diverge greatly on the validity of [this topic] today. Some physicists think that it fails at extreme short distances, others maintain that it fails to predict the behavior of large complex systems, and others yet hold that it fails when dealing with conscious systems.” Conscious systems refer to systems where the observer determines the outcome.

Gross said that one major issue today is whether there could ever be a physical theory of biology.
If evolution could be qualitatively examined, Gross surmised, one day we might be able to tell the shape of an organism simply by looking at its genome.

The main difficulty with a physical theory of biology is that biology is often concerned with a wide range of time scales, which is hard to approximate in physics.

Gross concluded his lecture by answering the question: “Will physics continue to be important in our future?” with an emphatic “Yes, definitely.”