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Gross talks physics and the history of the universe

Can you construct a machine with free will? Will the universe accelerate forever? And how will the universe end? These were the questions that David Gross, winner of the 2004 Nobel Prize in Physics, addressed during his lecture at McGill on Thursday.

Born in Washington, D.C., Gross completed his undergraduate and master’s degrees at Hebrew University in Jerusalem before earning his PhD at the University of California, Berkeley in 1966. Gross received his Nobel Prize for his discovery of asymptotic freedom, a key contribution to quantum field theory. He is currently the director of the Institute for Theoretical Physics at the University of California, Santa Barbara.

In his lecture on Thursday, Gross briefly summarized what physics has accomplished over the last 50 years, highlighting physicists’ attempts to map out the history of the universe.

“The most important product of knowledge is ignorance,” said Gross, setting the stage for his discussion of current inquiries in theoretical physics and its related fields.

The question of what precisely happened in the moments after the Big Bang is a subject of particular interest to Gross, though he admitted that “nobody has the vaguest idea” of the answer.

“It is not just an interesting question of why, of curiosity, although that is enough motivation,” said Gross, who acknowledged that all previous attempts to answer the question have been either religious or philosophical. “But it’s a question that I, as a particle or string theorist, would like to know to tell my friends, the cosmologists, what happened at the Big Bang. They need to know in order to explain those variations in temperature that occurred a few hundred thousand years later that led to all of these galaxies that form a billion years later.”

In his lecture, Gross leaped between issues surrounding vacuums, quantum mechanics, string theory, space, time, and gravity, among various other topics, before segueing into an extended discussion of consciousness and biology.

“Is there a theory of biology?” Gross asked. “And even if there is a theory of biology, can theoretical physics have one? The answer to that is probably yes.”

For Gross, a theory of biology would only be a first step from which scientists could approach other questions, such as, “What are the mechanism and the principles that underline consciousness or memory?”

Those in attendance seemed to find Gross’s references to biology – specifically regarding scientists’ ability to measure the onset of consciousness in an infant, particularly – intriguing.

“His connection with biology was very interesting,” said Mahammed Myi, a PhD candidate in physics at McGill. “The notion that you can ask questions about consciousness the way you ask questions about physics is an extremely curious topic by itself.”

Martin Grant, dean of the Faculty of Science, who also specializes in theoretical physics, echoed Myi’s comments on the lecture.

“I thought it was great the way he played up the importance of interdisciplinary study, and the idea of biology and physics working together,” Grant said. “The tricks that we have in physics for understanding theories and developing models may be applicable to other areas as far as how the brain works, how evolution takes place, or how consciousness takes place.

After the lecture, Gross reflected on the issues he had brought up, saying that choosing his favourite question was like “choosing your favourite kid.”

“What I hope is that there were young people in the audience who think that physics is still interesting, that physics is alive and well,” Gross said. “I think the questions we ask today are interesting – more interesting than when I started out.”

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