Category Archives: Science

Does Spacetime Emerge From Quantum Information?

Quantizing gravity is an important goal of contemporary physics, but after decades of effort it’s proven to be an extremely tough nut to crack. So it’s worth considering a very slight shift of emphasis. What if the right strategy is … Continue reading

Posted in arxiv, Science | 35 Comments

How to Build a Cloud Chamber to Detect Cosmic Rays

Sorry, I have no idea how to build a cloud chamber, I’m just a theorist. But Samatha here can help you out (and be much more charming than I would be in the process).

Posted in Science | 8 Comments

Quantum Field Theory and the Limits of Knowledge

Last week I had the pleasure of giving a seminar to the philosophy department at the University of North Carolina. Ordinarily I would have talked about the only really philosophical work I’ve done recently (or arguably ever), deriving the Born … Continue reading

Posted in Philosophy, Science | 59 Comments

The Reality of Time

The idea that time isn’t “real” is an ancient one — if we’re allowed to refer to things as “ancient” under the supposition that time isn’t real. You will recall the humorous debate we had at our Setting Time Aright … Continue reading

Posted in Philosophy, Science, Time | 79 Comments

What Happens Inside the Quantum Wave Function?

Many things can “happen” inside a quantum wave function, of course, including everything that actually does happen — formation of galaxies, origin of life, Lady Gaga concerts, you name it. But given a certain quantum wave function, what actual is … Continue reading

Posted in Science | 60 Comments

The Big Questions

The other day I mused on Twitter about three big origin questions: the origin of the universe, the origin of life, and the origin of consciousness. Which isn’t to say they are related, just that they’re all interesting and important … Continue reading

Posted in Science | 71 Comments

Guest Post: An Interview with Jamie Bock of BICEP2

If you’re reading this you probably know about the BICEP2 experiment, a radio telescope at the South Pole that measured a particular polarization signal known as “B-modes” in the cosmic microwaves background radiation. Cosmologists were very excited at the prospect … Continue reading

Posted in Guest Post, Science | 10 Comments

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 | 115 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 | 26 Comments