“We don’t know how good a theory is until it has a competitor,” he said. “The big advantage [to VSL theory] is that you always have a rigid variation in the speed of light nowadays.”

The Portuguese physicist spoke last night to promote his new book, Faster than the Speed of Light: The Story of A Scientific Speculation—one which he hopes will give both scholars and non-academics new insight into his theories.

His ideas have made the 34-year-old somewhat of a popular figure.

Even though his speculations have yet to be proven or disproven conclusively, he has appeared in many articles, on television and he is currently on a three-week book tour in the U.S. and the United Kingdom.

Though he was well-received last night, garnering laughs with his frequent sharp jokes, many were not entirely convinced that his speech was accurate.

“Obviously, it was aimed a level to be popular,” said Stanley Fay, a professor of Calculus at Mass Bay Community College. “Consequently it did not have any proof.”

—Staff writer Alexandra N. Atiya can be reached at atiya@fas.harvard.edu