Category Archives: Science

The Wrong Objections to the Many-Worlds Interpretation of Quantum Mechanics

Longtime readers know that I’ve made a bit of an effort to help people understand, and perhaps even grow to respect, the Everett or Many-Worlds Interpretation of Quantum Mechanics (MWI) . I’ve even written papers about it. It’s a controversial … Continue reading

Posted in Science | 108 Comments

Problem Book in Relativity and Gravitation: Free Online!

If I were ever to publish a second edition of Spacetime and Geometry — unlikely, but check back in another ten years — one thing I would like to do would be to increase the number of problems at the … Continue reading

Posted in Science | 9 Comments

The State of the Early Universe

Well hello, blog. It’s been too long! Feels good to be back. The big cosmological excitement this week was the announcement of new cosmic microwave background measurements. These include a big release of new papers from the Planck satellite, as … Continue reading

Posted in Science | 25 Comments

Dark Matter, Explained

If you’ve ever wondered about dark matter, or been asked puzzled questions about it by your friends, now you have something to point to: this charming video by 11-year-old Lucas Belz-Koeling. (Hat tip Sir Harry Kroto.) The title references “Draw … Continue reading

Posted in Science | 38 Comments

Life Is the Flame of a Candle

Last October I was privileged to be awarded the Emperor Has No Clothes award from the Freedom From Religion Foundation. The physical trophy consists of the dashing statuette here on the right, presumably the titular Emperor. It’s made by the … Continue reading

Posted in Humanity, Philosophy, Religion, Science | 79 Comments

Guest Post: Chip Sebens on the Many-Interacting-Worlds Approach to Quantum Mechanics

I got to know Charles “Chip” Sebens back in 2012, when he emailed to ask if he could spend the summer at Caltech. Chip is a graduate student in the philosophy department at the University of Michigan, and like many … Continue reading

Posted in Guest Post, Philosophy, Science | 55 Comments

Slow Life

Watch and savor this remarkable video by Daniel Stoupin. It shows tiny marine animals in motion — motions that are typically so slow that we would never notice, here enormously sped-up so that humans can appreciate them. Slow Life from … Continue reading

Posted in Arts, Science | 11 Comments

Where Have We Tested Gravity?

General relativity is a rich theory that makes a wide variety of experimental predictions. It’s been tested many ways, and always seems to pass with flying colors. But there’s always the possibility that a different test in a new regime … Continue reading

Posted in arxiv, Science | 32 Comments

Einstein’s Papers Online

If any scientist in recent memory deserves to have every one of their words captured and distributed widely, it’s Albert Einstein. Surprisingly, many of his writings have been hard to get a hold of, especially in English; he wrote an … Continue reading

Posted in Science, Words | 35 Comments


This year we give thanks for a technique that is central to both physics and mathematics: the Fourier transform. (We’ve previously given thanks for the Standard Model Lagrangian, Hubble’s Law, the Spin-Statistics Theorem, conservation of momentum, effective field theory, the … Continue reading

Posted in Math, Science | 26 Comments