Monthly Archives: March 2014

Guest Post: Jaroslav Trnka on the Amplituhedron

Usually, technical advances in mathematical physics don’t generate a lot of news buzz. But last year a story in Quanta proved to be an exception. It relayed the news of an intriguing new way to think about quantum field theory … Continue reading

Posted in Guest Post, Science | 26 Comments

Naturalness in the NYT

In the wake of the announcement of gravitational-wave signatures from inflation in the cosmic microwave background, I was invited to contribute a piece to The Stone section of the New York Times, on “naturalness” and how it’s used in physics. … Continue reading

Posted in Science | 30 Comments

A Great Time for Reason and Science

Here I am at an extremely stimulating meeting on gravity and quantum spacetime in Santa Barbara, but I skipped yesterday’s afternoon session to talk on the PBS News Hour about the new inflation results: There’s a great parallel (if the … Continue reading

Posted in Science | 53 Comments

BICEP2 Updates

Here are the main results on gravitational waves/B-modes from the CMB, as reported by the BICEP2 experiment. For background see my previous post. All of the BICEP2 results and plots are here. First, the best fit to r, the ratio … Continue reading

Posted in Science | 56 Comments

Gravitational Waves in the Cosmic Microwave Background

Major announcement coming! [Update: Of course by now the announcement has come, of the discovery of signatures of gravitational waves in the cosmic microwave background by the BICEP2 experiment, more or less as the post below surmised. This follow-up post … Continue reading

Posted in Science | 109 Comments

Einstein and Pi

Each year, the 14th of March is celebrated by scientifically-minded folks for two good reasons. First, it’s Einstein’s birthday (happy 135th, Albert!). Second, it’s Pi Day, because 3/14 is the closest calendrical approximation we have to the decimal expansion of … Continue reading

Posted in Humor, Science | 53 Comments

A Bit of Physics History: Ed Witten Introduces M-Theory

The Second Superstring Revolution was, like most revolutions, a somewhat messy affair, with a number of pivotal steps along the way: understanding the role of membranes in 11-dimensional supergravity, the discovery of dualities in supersymmetric gauge theories, Polchinski’s appreciation of … Continue reading

Posted in arxiv, Science | 15 Comments

Guest Post: Katherine Freese on Dark Matter Developments

The hunt for dark matter has been heating up once again, driven (as usual) by tantalizing experimental hints. This time the hints are coming mainly from outer space rather than underground laboratories, which makes them harder to check independently, but … Continue reading

Posted in Guest Post, Science | 23 Comments

Effective Field Theory and Large-Scale Structure

Been falling behind on my favorite thing to do on the blog: post summaries of my own research papers. Back in October I submitted a paper with two Caltech colleagues, postdoc Stefan Leichenauer and grad student Jason Pollack, on the … Continue reading

Posted in arxiv, Science | 8 Comments


Almost forgot again — the leap-year thing always gets me. But I’ve now officially been blogging for ten years. Over 2,000 posts, generating over 57,000 comments. I don’t have accurate stats because I’ve moved around a bit, but on the … Continue reading

Posted in Blog, Personal | 12 Comments