About John Preskill

I am a theoretical physicist at Caltech, and the Director of the Institute for Quantum Information and Matter. Follow me on Twitter @preskill.
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Frontiers of Quantum Information Science

Just a few years ago, if you wanted to look for recent research articles about quantum entanglement, you would check out the quantum physics [quant-ph] archive at Since 1994, quant-ph has been the central repository for papers about quantum computing and the broader field of quantum information science. But over the past few years [...]

2017-01-13T10:05:50-08:00September 22nd, 2013|News|6 Comments

Free Feynman!

Last Friday the 13th was a lucky day for those who love physics --- The online html version of Volume 1 of the Feynman Lectures on Physics (FLP) was released! Now anyone with Internet access and a web browser can enjoy these unique lectures for free. They look beautiful. Mike Gottlieb at Caltech on [...]

2017-01-13T10:05:50-08:00September 21st, 2013|News|9 Comments

What’s inside a black hole?

I have a multiple choice question for you. What's inside a black hole? (A) An unlimited amount of stuff. (B) Nothing at all. (C) A huge but finite amount of stuff, which is also outside the black hole. (D) None of the above. The first three answers all seem absurd, boosting the credibility of (D). [...]

2017-01-13T10:05:51-08:00August 29th, 2013|Theoretical highlights|78 Comments

We are all Wilsonians now

Ken Wilson Ken Wilson passed away on June 15 at age 77. He changed how we think about physics. Renormalization theory, first formulated systematically by Freeman Dyson in 1949, cured the flaws of quantum electrodynamics and turned it into a precise computational tool. But the subject seemed magical and mysterious. Many physicists, Dirac [...]

2017-01-13T10:05:53-08:00June 18th, 2013|Reflections, The expert's corner|26 Comments

Entanglement = Wormholes

One of the most enjoyable and inspiring physics papers I have read in recent years is this one by Mark Van Raamsdonk. Building on earlier observations by Maldacena and by Ryu and Takayanagi. Van Raamsdonk proposed that quantum entanglement is the fundamental ingredient underlying spacetime geometry.* Since my first encounter with this provocative paper, I [...]

A Public Lecture on Quantum Information

Sooner or later, most scientists are asked to deliver a public lecture about their research specialties. When successful, lecturing about science to the lay public can give one a feeling of deep satisfaction. But preparing the lecture is a lot of work! Caltech sponsors the Earnest C. Watson lecture series (named after the same Earnest [...]

Remembering Arthur Wightman

Arthur Wightman Arthur Wightman passed away this past January, at age 90. He was one of the great mathematical physicists of the past century. Two of Arthur’s most renowned students, Arthur Jaffe and Barry Simon, wrote an affectionate obituary. I thought I would add some reminiscences of my own — [...]

2017-01-13T10:05:55-08:00March 13th, 2013|Reflections|5 Comments