Author Archives: Sean Carroll

Why Is There Something, Rather Than Nothing?

A good question! Or is it? I’ve talked before about the issue of why the universe exists at all (1, 2), but now I’ve had the opportunity to do a relatively careful job with it, courtesy of Eleanor Knox and … Continue reading

Posted in arxiv, Philosophy, Science | 114 Comments

Guest Post: Nicole Yunger Halpern on What Makes Extraordinary Science Extraordinary

Nicole Yunger Halpern is a theoretical physicist at Caltech’s Institute for Quantum Information and Matter (IQIM).  She blends quantum information theory with thermodynamics and applies the combination across science, including to condensed matter; black-hole physics; and atomic, molecular, and optical … Continue reading

Posted in Guest Post, Science | 8 Comments

Beyond Falsifiability

I have a backlog of fun papers that I haven’t yet talked about on the blog, so I’m going to try to work through them in reverse chronological order. I just came out with a philosophically-oriented paper on the thorny … Continue reading

Posted in arxiv, Philosophy, Science | 40 Comments


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

The Big Picture: Paperback Day

I presume most readers of this blog have already purchased their copy of The Big Picture: On the Origins of Life, Meaning, and the Universe Itself. If you’re really dedicated, you have the hardback version and the ebook and the … Continue reading

Posted in Big Picture | 43 Comments