Physics and astronomy professor Robert Caldwell was one of 13 American theoretical physicists who was awarded a Simons Foundation fellowship in theoretical physics this year. The fellowship is designed to support sabbatical work for research in mathematics and physical sciences.
Caldwell is the first theoretical physicist from Dartmouth ever to receive the fellowship. Physics and astronomy professor Marcelo Gleiser said that Simons Foundation fellowships are difficult to earn and that it is very significant that one of Dartmouth’s faculty members is a recipient.
Caldwell had already planned for a two-term sabbatical leave, but the fellowship will allow him to add an additional term to his sabbatical, which will now last from fall of 2017 to spring of 2018, he said.
As a theoretical physicist, Caldwell focuses on cosmology. He is particularly interested in questions about the large scale structure, history and evolution of the universe. He is also interested in dark energy and its influences on the expansion of the universe.
“People often have this picture that the Big Bang is something that happened in the past and that it’s slowing down, like there was an explosion, and it’s running out of energy, but the expansion is speeding up,” Caldwell said. “Something is going on — it is a mystery.”
Gleiser said that Caldwell has been a pioneer in trying to understand what kind of physical mechanisms could be pushing the universe apart in such a dramatic way. Gleiser added that Caldwell is innovating ways to collect dark energy and suggesting possible models that could describe it.
“One of the wonderful things about [Caldwell] is that he’s unafraid to put out new ideas — we can be skittish about proposing far-fetched ideas, but he does it, and it catches on like fire,” Gleiser said.
Gleiser said that Caldwell has proposed a widely-cited theory called “the Big Rip,” as opposed to “the Big Bang.” His theory deals with the idea of cosmic acceleration and whether the universe will be torn apart if it continues.
Along with his research capabilities, Caldwell’s students speak highly of him as a professor.
Jack Neustadt ’17 , a student in Caldwell’s class Physics 66, “Relativistic Electrodynamics,” said that Caldwell explains concepts well and is helpful as a professor.
“Just because you’re a good researcher doesn’t mean you’re a good teacher or professor,” Neustadt said. “And I feel like so far, I’ve learned a lot.”
Echoing Neustadt’s comment, Hang Qi ’19 said that Caldwell introduces the history of concepts as well as concepts themselves, making it easier for her to understand. She said that Caldwell has an expansive range of knowledge about physics and that he often helps students in areas of physics that are different from what the class itself explores.
The sabbatical will allow Caldwell to investigate his interests in more depth, he said. Caldwell will be going to the University of California, Berkeley and the University of California, San Diego to work with cosmology groups that are studying variations on Albert Einstein’s theory of general relativity.
As a theorist, Caldwell said that his time in California will not be spent working on new equipment. Instead, he will focus on collaborating with his colleagues on how to measure and test theories about the early universe.
