← All stories
Science

Leading Physicist Admits He Once Told Students Their Great Ideas Were Wrong

Theories of Everything · Juan Maldacena: Geometry as Entanglement, and the Emergence of Spacetime · May 10, 2026
Leading Physicist Admits He Once Told Students Their Great Ideas Were Wrong
Theories of Everything
Theories of Everything
Juan Maldacena: Geometry as Entanglement, and the Emergence of Spacetime
"Many times I've told my students that what they said were wrong and they ended up being great ideas. A person called Eitor Leikowicz came with an interesting generalization of this formula for the Ryu and Takayanagi that we were talking about. And I said, well, I thought it was probably wrong. And not justified. But in the end it was correct. Unfortunately he didn't publish it. The other people published it. So that was one of my failures as an advisor."
Juan Maldacena revealed that one of his PhD students proposed a major generalization of the Ryu-Takayanagi formula for black hole entropy, which Maldacena initially rejected as incorrect. The idea turned out to be valid but the student never published, and others later claimed credit. Maldacena described this as one of his failures as an advisor, offering a rare glimpse into how breakthrough physics can be dismissed even by top experts.

About this episode

In this episode of Theories of Everything, host Curt Jaimungal interviews Juan Maldacena, the theoretical physicist behind the most-cited paper in the field and architect of the AdS/CFT correspondence. Maldacena explains that spacetime in general relativity is not made of anything more fundamental, but quantum considerations suggest it may emerge from quantum degrees of freedom living on the boundary of spacetime. The conversation explores black hole interiors, where singularities represent places physics currently cannot describe, and the recent island formula breakthroughs by Pennington and Witten that resolve how black holes preserve quantum information. Maldacena reveals he is actively working to resolve fundamental incompatibilities surrounding wormholes in quantum gravity, describing them as 'leaky pipes' where different theoretical frameworks do not fit together. He argues that quantum gravity requires observers to be included in the system, stating there is no 'view from nowhere' and that measurements are fundamentally embedded in spacetime structure. On cosmology, Maldacena expressed skepticism about DESI results suggesting dark energy's equation of state might be below -1, calling such a finding potentially the biggest news in 100 years but predicting it will not survive scrutiny. The episode closes with Maldacena sharing that as a graduate student he struggled with feelings of inadequacy, advising students to persist, question lore in their fields, and understand concepts deeply rather than repeating what everyone says.

Key takeaways

More stories More from Theories of Everything