Fields and reality

The world is really made out of fields. Sometimes the stuff of the universe looks like particles, due to the peculiarities of quantum mechanics, but deep down it’s really fields. Empty space isn’t as empty as it looks. At every point there is a rich collection of fields, each taking on some value or another—or more precisely, due to the uncertainty that accompanies quantum mechanics, a distribution of possible values we could potentially observe.

The fields themselves aren’t “made of” anything—fields are what the world is made of. We don’t know of any lower level of reality. (Maybe string theory, but that’s still hypothetical.) Magnetism is carried by a field, as are gravity and the nuclear forces. Even what we call “matter”—particles like electrons and protons—is really just a set of vibrating fields. The particle we call the “Higgs boson” is important, but not so much for its own sake; what matters is the Higgs field from which it springs, which plays a central role in how our universe works. Astounding indeed.

Sean Carroll, The particle at the end of the universe

Don’t look: waves. Look: particles.

The physicist John Wheeler once proposed a challenge: How can you best explain quantum mechanics in five words or fewer? In the modern world, it’s easy to get suggestions for any short-answer question: Simply ask Twitter, the microblogging service that limits posts to 140 characters. When I posed the question about quantum mechanics, the best answer was given by Aatish Bhatia (@ aatishb): “Don’t look: waves. Look: particles.” That’s quantum mechanics in a nutshell.

Sean Carroll, The particle at the end of the universe