Physics Blog
All about Physics

“I would be very interested in a post about quantum fields. Are they generally/universally believed to be real and the most fundamental aspect of our universe or just a mathematical construct? I’ve read that there are 24 fundamental quantum fields: 12 fields for fermions and 12 for bosons. But I’ve also read about quantum fields for atoms, molecules, etc. How does that work? Does everything emerge from these 24 fields and their interactions?”

When you think about the Universe, you probably think about it in a very particular fashion. There’s spacetime: the backdrop upon which the matter in the Universe exists, and then there are particles and antiparticles, which make up everything we can conceive of in the cosmos. Only, the quantum nature of reality is very different from this intuitive picture, and quantum field theory goes a few steps farther than even the unintuitive pictures we have in our heads. What if Heisenberg uncertainty, the Pauli exclusion principle, wave-particle duality and more were all just manifestations of something very basic: quantum fields themselves?

“Our Universe is an intricate, amazing place, and yet our greatest hopes of a unified theory — a theory of everything — seek to decrease the number of fundamental constants we need. In reality, though, the more we learn about the Universe, the more parameters we’re learning it takes to fully describe it. It’s important to recognize where we are and what it takes, today, to describe the entirety of what’s known.

But we still don’t know everything, and so it’s also important to keep searching for a more complete paradigm. If we’re successful, it will give us absolutely everything the Universe has in it, including solutions to our current mysteries. The hope of many, but not a requirement, is that the Universe will wind up being simpler than we currently know. Right now, unfortunately, anything simpler than what’s been put forth here is too simple to work. Our Universe may not be elegant, after all.”

Think about everything that exists in our Universe. We have the four fundamental forces: gravity, electromagnetism, and the strong and weak nuclear forces. We have all the particles and antiparticles of the Standard Model; we have the bosons; we have the ways that particle behavior changes dependent on energy. We have hundreds of known composite particles and the ways that they interact, couple and decay. For everything that’s known, there are at least 26 fundamental constants required to explain the Universe on top of the laws of physics themselves, and still, they don’t give us everything.