How Many Elementary Particles Are There, Really? | Quanta Magazine
About Quanta
Search
Search for:
Search<br>Search
Newsletter
Get the latest news delivered to your inbox.
Subscribe
Recent newsletters
Follow Quanta
Youtube
RSS
An editorially independent publication supported by the Simons Foundation.
Type search term(s) and press enter
What are you looking for?
Search
Home
How Many Elementary Particles Are There, Really?
Comment
Save Article
Read Later
Share
Copied!
Copy link
Ycombinator
Comment
Comments
Save Article<br>Read Later
Read Later
Qualia
How Many Elementary Particles Are There, Really?
By
Natalie Wolchover
June 15, 2026
Plausible answers range from 17 to — in all seriousness — 995.5.
Comment
Save Article
Read Later
Kristina Armitage/Quanta Magazine
Introduction
By Natalie Wolchover
Columnist
June 15, 2026
View PDF/Print Mode
essays
Higgs boson
Large Hadron Collider
particle physics
physics
Qualia
quantum physics
standard model
All topics
Every time I write about particle physics, I encounter a moment of uncertainty about a quantity that, at first glance, ought to be clear. How many kinds of elementary particles should I say there are?
In experiments at the Large Hadron Collider, physicists smash together beams of protons, breaking them up into all possible elementary bits and pieces. Meanwhile, they have an incredibly accurate set of mathematical equations for describing these building blocks and all the ways they fit together. So, since the known particles of nature can be both empirically observed and theoretically described, you would think they could also be counted. But alas not. I knew that, for reasons we’ll see, the census is not so easy as it seems.
So I recently emailed a few physicists to ask how each of them personally tallies nature’s fundamental constituents. The first indicator of just how complicated the issue is came in a reply from David Tong, the University of Cambridge physicist and textbook author, when we were scheduling a video call: “P.S. I think the true answer to your question is not an integer!”
p]:my-6 [&>ul]:my-6 [&>ol]:my-6 [&>p]:text-3-5 [&>p]:leading-6.5 [&>li]:text-3-5 [&>li]:leading-6.5 [&_img.alignleft]:float-left [&_img.alignleft]:mr-5 [&_img.alignleft]:ml-0 [&_img.alignleft]:my-5 [&_img.alignright]:float-right [&_img.alignright]:ml-5 [&_img.alignright]:mr-0 [&_img.alignright]:my-5 [&_figure]:m-0 [&_figcaption]:relative [&_figcaption]:flex [&_figcaption]:flex-col [&_figcaption]:gap-2 [&_figcaption]:pt-2 [&_figcaption]:pb-4-5 [&_figcaption]:mt-0 [&_figcaption]:mb-6 &_figcaption]:font-pangram [&_figcaption]:after:content-[""] [&_figcaption]:after:absolute [&_figcaption]:after:bottom-0 [&_figcaption]:after:w-11 [&_figcaption]:after:h-0.5 [&_figcaption]:after:bg-gray-1a1 [&_.caption]:block [&_.caption]:font-pangram [&_.caption]:text-0xxs [&_.caption]:leading-4-5 [&_.caption]:m-0 [&_.attribution]:block [&_.attribution]:font-pangram [&_.attribution]:text-xs [&_.attribution]:leading-4-5 [&_.attribution]:m-0 [&_.attribution]:before:content-none show-dropcap" style="color: #000000;"><br>I n philosophy, “qualia” refers to the subjective qualities of our experience: what it’s like for Alice to see blue or for Bob to feel delighted. Qualia are “the ways things seem to us,” as the late philosopher Daniel Dennett put it. In these essays, our columnists follow their curiosity, and explore important but not necessarily answerable scientific questions.
We’ll get to that (it comes from a mysterious calculation from 2011), but let’s enter this rabbit hole from the top.
The known elementary particles and their interactions obey a set of equations called the Standard Model of particle physics. The Standard Model is a “quantum field theory,” a mathematical description of reality in which entities called quantum fields permeate the universe. Ripples moving through these fields are what we call elementary particles; some behave like matter, while others impart forces. The quantum fields and associated particles in the Standard Model underlie all known physical phenomena other than gravity, dark matter, and dark energy (all of which take unknown forms at a fundamental level).
In posters on classroom walls, the Standard Model displays 17 particles. There are 12 matter particles, or fermions: the electron, muon, and tau; three neutrinos; and six quarks. Each of them has a distinct set of sensitivities to various forces. There are also four force-carrying particles, or “bosons”: the photon (which imparts the electromagnetic force), the W and Z bosons (the weak force), and the gluon (the strong force). Finally, there’s the Higgs boson, a so-called scalar particle that’s neither matter nor force; rather, it imbues other particles with mass through its interactions with them.
Samuel Velasco/Quanta Magazine
It may just be this simple. “I think 17 is the right answer,” Melissa...