Book · General · Language · Media · Site

Reality is fields

John Healy

Physics was a requirement for the first two years when I was an undergrad. That introduced me to The Feynman Lectures on Physics, three heavy red volumes (© 1963, 1964, 1965). The preface in each volume had a picture of Feynman playing the bongo drums.

And then the early morning physics labs. Two of the experiments I remember were Millikan’s Oil Drop and the Double-slit. The later was a continuation of the particle-wave narrative about light and other atomic particles (which had been introduced in high school physics). My takeaway was “okay, light acts as both a particle and a wave — what’s next?” Must be something else at a deeper level; but no big metaphysical deal, eh.

“A wave is sort of a vibration in a field.” So, the debate was really about particles and fields. Quantum field theory was next.

But it was a big deal. Physicists had spent decades debating the primacy of one theory or the other. And in decades since. That’s why I was interested in Sean Carroll’s Faraday lecture at the Royal Institution of Great Britain on October 17, 2012. I highly recommend viewing the three videos on his site (the link in the previous sentence).

The first video is titled after his book The Particle at the End of the Universe. In that lecture he develops an answer to the question, “What is more important — the particle aspect of reality or the field aspect of reality?”

After some background, he just outright says, “It’s fields — that’s the answer, it’s not a mystery.” I was struck by a brief aside that he went decades of his life without an answer …  “The reason why the Higgs boson is a concept that’s hard to grasp is that you need to stop thinking of the world as particles. … That’s the secret we physicists have never told you.” Watch the video for more.

But that was the “wow!” moment. I’d been thinking about whether there are any square waves in nature and Fourier transforms — how adding waveforms (sinusoidal oscillations at various wavelengths) produces other waveforms, and how waveforms can be decomposed into component waveforms [1]. Sure enough, Carroll explains that space is full of fields, “at every point in space, there’s dozens of little vibrating fields … when you look at the fields closely enough they resolve into individual particles.” (Can we say particles are contextual realities?)

As far as the LHC and Higgs boson (“the last piece of the puzzle”), read his book.

The second video is a 30 minute Q&A with the audience. The third video is a 7 minute individual Q&A which was done ahead of the lecture.

[1] Here’s a slide from another lecture “Quantum Field Theory and the Limits of Knowledge” which illustrates the concept of particles from fields.

lecture slide
Sean Carroll, Quantum Field Theory and the Limits of Knowledge

3 thoughts on “Reality is fields”

  1. Space.com‘s Spaceman1 on May 5, 2017, wrote that:

    But modern particle physics isn’t really about the particles themselves, and that goes for the Higgs boson, too. No, in the contemporary view of the rules of the universe, the primary physical object is the field, an entity that permeates all of space and time. This field can take different values at different points in space-time, and each value corresponds to the average number of particles observers see in that patch. In this view (and indeed, in reality), particles can be created and destroyed at will, simply by adding or removing energy from the field.

    In other words, you can slap a field and make some particles. A single particle is just the minimum possible amount of energy that a field can support. Every kind of particle that scientists know of, from the electron to a photon, is associated with its own space-time-filling vibrating field.

    [1] Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at COSI science center. Sutter is also host of Ask a Spaceman, RealSpace and COSI Science Now. He contributed this article to Space.com’s Expert Voices: Op-Ed & Insights.

  2. In this YouTube video of David Tong’s lecture “Quantum Fields: The Real Building Blocks of the Universe” 1 published on Feb 15, 2017, in The Royal Institution’s channel, he echoes Sean Carroll’s portrayal of the universe:

    In fact, the very best theories we have of physics don’t rely on particles at all. The best theories we have tell us that the fundamental building blocks of nature are not particles, but something much more nebulous and abstract. The fundamental building blocks of nature are fluid-like substances which are spread throughout the entire universe and ripple in strange and interesting ways. That’s the fundamental reality in which we live. These fluid-like substances we have a name for. We call them fields.

    The physicist’s definition of a field is the following. It’s something that, as I said, is spread everywhere throughout the universe. It’s something that takes a particular value at every point in space. And what’s more, that value can change in time. So a good picture to have your mind is fluid, which ripples and sways throughout the universe.

    [1] Tong is a professor of theoretical physics at Cambridge University, specialising in quantum field theory.

  3. What’s really happening during an LHC collision?

    Space is permeated with dormant fields that can briefly pop a particle into existence when vibrated with the right amount of energy. These fields play important roles but almost always work behind the scenes. The Higgs field, for instance, is always interacting with other particles to help them gain mass. But a Higgs particle will only appear if the field is plucked with the right resonance.

Comments are closed.