Category Archives: Science

Thanksgiving

This year we give thanks for a simple but profound principle of statistical mechanics that extends the famous Second Law of Thermodynamics: the Jarzynski Equality. (We’ve previously given thanks for the Standard Model Lagrangian, Hubble’s Law, the Spin-Statistics Theorem, conservation … Continue reading

Posted in Science | 13 Comments

Standard Sirens

Everyone is rightly excited about the latest gravitational-wave discovery. The LIGO observatory, recently joined by its European partner VIRGO, had previously seen gravitational waves from coalescing black holes. Which is super-awesome, but also a bit lonely — black holes are … Continue reading

Posted in Science | 43 Comments

Mind-Blowing Quantum Mechanics

Trying to climb out from underneath a large pile of looming (and missed) deadlines, and in the process I’m hoping to ramp back up the real blogging. In the meantime, here are a couple of videos to tide you over. … Continue reading

Posted in Science | 14 Comments

Joe Polchinski’s Memories, and a Mark Wise Movie

Joe Polchinski, a universally-admired theoretical physicist at the Kavli Institute for Theoretical Physics in Santa Barbara, recently posted a 150-page writeup of his memories of doing research over the years. Memories of a Theoretical Physicist Joseph Polchinski While I was … Continue reading

Posted in arxiv, Humor, Personal, Science | 3 Comments

A Response to “On the time lags of the LIGO signals” (Guest Post)

This is a special guest post by Ian Harry, postdoctoral physicist at the Max Planck Institute for Gravitational Physics, Potsdam-Golm. You may have seen stories about a paper that recently appeared, which called into question whether the LIGO gravitational-wave observatory … Continue reading

Posted in Guest Post, Science | 15 Comments

Congratulations to Grant and Jason!

Advising graduate students as they make the journey from learners to working scientists is one of the great pleasures and privileges of academic life. Last week featured the Ph.D. thesis defenses of not one, but two students I’ve been working … Continue reading

Posted in Academia, Personal, Science | 7 Comments

Guest Post: Nathan Moynihan on Amplitudes for Astrophysicists

As someone who sits at Richard Feynman’s old desk, I take Feynman diagrams very seriously. They are a very convenient and powerful way of answering a certain kind of important physical question: given some set of particles coming together to … Continue reading

Posted in Guest Post, Science | 6 Comments

Is Inflationary Cosmology Science?

[tl;dr: Check out this article in Scientific American by Ijjas, Steinhardt, and Loeb suggesting that inflation isn’t science; this response by Guth, Kaiser, Linde, and Nomura that was co-signed by a bunch of people including me; and this counter-response by … Continue reading

Posted in Philosophy, Science | 25 Comments

What Happened at the Big Bang?

I had the pleasure earlier this month of giving a plenary lecture at a meeting of the American Astronomical Society. Unfortunately, as far as I know they don’t record the lectures on video. So here, at least, are the slides … Continue reading

Posted in Science, Time | 71 Comments

Quantum Is Calling

Hollywood celebrities are, in many important ways, different from the rest of us. But we are united by one crucial similarity: we are all fascinated by quantum mechanics. This was demonstrated to great effect last year, when Paul Rudd and … Continue reading

Posted in Entertainment, Science | 5 Comments