Lee Smolin

Smolin was born in New York City to Michael Smolin, an environmental and process engineer and Pauline Smolin, a playwright. Smolin said his parents were Jewish followers of the Fourth Way, founded by George Gurdjieff, an Armenian mystic. Smolin describes himself as Jewish. His brother, David M. Smolin, became a professor at the Cumberland School of Law in Birmingham, Alabama.

Smolin dropped out of Walnut Hills High School in Cincinnati, Ohio. His interest in physics began at that time when he read Einstein's reflections on the two tasks he would leave unfinished at his death: 1, to make sense of quantum mechanics, and, 2 to unify that understanding of the quanta with gravity. Smolin would take it as his "mission" to try to complete these tasks. Shortly afterward, he browsed the Physics Library at the University of Cincinnati, where he came across Louis de Broglie's pilot wave theory in French. "I still can close my eyes," Smolin wrote in Einstein's Unfinished Revolution, "and see a page of the book, displaying the equation that relates wavelength to momentum." Soon after that he would "talk his way into" Hampshire College, find great teachers, and get lucky in his applications to graduate school. As to his mission of solving Einstein's two big questions, by Smolin's account, he did not succeed; "Very unfortunately, neither has anyone else."

He held postdoctoral research positions at the Institute for Advanced Study in Princeton, New Jersey, the Kavli Institute for Theoretical Physics in Santa Barbara, and the University of Chicago, before becoming a faculty member at Yale, Syracuse, and Pennsylvania State Universities. He was a visiting scholar at the Institute for Advanced Study in 1995 and a visiting professor at Imperial College London (1999–2001), before becoming one of the founding faculty members at the Perimeter Institute in 2001. In 2026, he agreed to "pause" his relationship with the Institute in light of revelations that he had maintained contact with Jeffrey Epstein after the latter's initial conviction.

Smolin contributed to the theory of loop quantum gravity (LQG) in collaborative work with Ted Jacobson, Carlo Rovelli, Louis Crane, Abhay Ashtekar and others. LQG is an approach to the unification of quantum mechanics with general relativity which utilizes a reformulation of general relativity in the language of gauge field theories, which allows the use of techniques from particle physics, particularly the expression of fields in terms of the dynamics of loops. With Rovelli he discovered the discreteness of areas and volumes and found their natural expression in terms of a discrete description of quantum geometry in terms of spin networks. In recent years he has focused on connecting LQG to phenomenology by developing implications for experimental tests of spacetime symmetries as well as investigating ways elementary particles and their interactions could emerge from spacetime geometry.

Between 1999 and 2002, Smolin made several proposals to provide a fundamental formulation of string theory that does not depend on approximate descriptions involving classical background spacetime models.

Smolin is among those theorists who have proposed that the effects of quantum gravity can be experimentally probed by searching for modifications in special relativity detected in observations of high energy astrophysical phenomena, including very high energy cosmic rays and photons and neutrinos from gamma ray bursts. Among Smolin's contributions are the co-invention of doubly special relativity (with João Magueijo, independently of work by Giovanni Amelino-Camelia), and of relative locality (with Amelino-Camelia, Laurent Freidel, and Jerzy Kowalski-Glikman).

Smolin has worked since the early 1980s on a series of proposals for hidden variables theories, which would be non-local deterministic theories which would give a precise description of individual quantum phenomena. In recent years, he has pioneered two new approaches to the interpretation of quantum mechanics suggested by his work on the reality of time, called the real ensemble interpretation and the principle of precedence.

Smolin's hypothesis of cosmological natural selection, also called the fecund universes theory, suggests that a process analogous to biological natural selection applies at the grandest of scales. …

Smolin's 2006 book The Trouble with Physics explored the role of controversy and disagreement in the progress of science. It argued that science progresses fastest if the scientific community encourages the widest possible disagreement among trained and accredited professionals prior to the formation of consensus brought about by experimental confirmation of predictions of falsifiable theories. He proposed that this meant the fostering of diverse competing research programs, and that premature formation of paradigms not forced by experimental facts can slow the progress of science.

As a case study, The Trouble with Physics focused on the issue of the falsifiability of string theory due to the proposals that the anthropic principle be used to explain the properties of our universe in the context of the string landscape. The book was criticized by physicist Joseph Polchinski and other string theorists.

In his earlier book Three Roads to Quantum Gravity (2002), Smolin stated that loop quantum gravity and string theory were essentially the same concept seen from different perspectives. In that book, he also favored the holographic principle. The Trouble with Physics, on the other hand, was strongly critical of the prominence of string theory in contemporary theoretical physics, which he believes has suppressed research in other promising approaches. Smolin suggests that string theory suffers from serious deficiencies and has an unhealthy near-monopoly in the particle theory community. He called for a diversity of approaches to quantum gravity, and argued that more attention should be paid to loop quantum gravity, an approach Smolin has devised. Finally, The Trouble with Physics is also broadly concerned with the role of controversy and the value of diverse approaches in the ethics and process of science.

In the same year that The Trouble with Physics was published, Peter Woit published Not Even Wrong, a book for nonspecialists whose conclusion was similar to Smolin's, namely that string theory was a fundamentally flawed research program.

Smolin has stayed involved with theatre becoming a scientific consultant for such plays as A Walk in the Woods by Lee Blessing, Background Interference by Drucilla Cornell, and Infinity by Hannah Moscovitch.

Smolin is married to Dina Graser, a lawyer and urban policy consultant in Toronto, Ontario. He was previously married to Fotini Markopoulou-Kalamara. His brother is law professor David M. Smolin.

In 2003, Smolin contributed a note to Jeffrey Epstein's birthday book. In 2019, Smolin told The Verge he had not been in contact with Epstein since 2008, the same year he had pleaded guilty to charges of solicitation of prostitution and of solicitation of prostitution with a minor under the age of 18. However, upon the release of the Epstein files in 2025 and 2026, it was found Smolin had been in contact with Epstein as recently as 2013. Among the emails was an invitation from Epstein to the US Virgin Islands in 2011. As a result, Smolin's working relationship with the Perimeter Institute was paused.