Chapter 3 – Elementary particles

Standard model

This chapter switches gear to dig into the elementary particles that make up matter and introduces the standard model.

The general understanding starts with matter made of molecules that are tightly lined atoms. Water is two hydrogen atoms linked to an oxygen atom.

Atoms are then made of a nucleus consisting or protons and neutrons that is orbited by electrons. The number of protons defines the type of atom. Hydrogen atoms have 1 proton, oxygen atoms have 8.

We get into the elementary particles when we start to go deeper. Protons and neutrons are each made of three particles called quarks. Quarks have strange names – a proton is made of two up quarks and a down quark, neutrons are made of one up quark and two down quarks.

This opens the door to the elementary particles that are the building blocks of the universe.

How were elementary particles discovered

Most elementary particles have been confirmed using particle accelerators. the largest is the Large Hadron Collider (LHC) in Switzerland that is an underground loop over 5 miles across where particles are accelerated to 99.999999% speed of light.

These particles smash into targets with high energy and the pieces that spin off are analyzed for signs of different particle types.

The Standard Model

Starting in the 1970s, the Standard Model was developed to explain the elementary particles. It is a structure for the 17 core particles backed by a mathematical framework that has produced amazingly accurate predictions.

The standard model breaks down like this:

• The first three columns are the particles that make up matter – each of these columns is a separate family
• Almost all matter is made of just three particles: up and down quarks and electrons in the first column
• The 4th column are the particles that are responsible for forces
• This Higgs particle on the right is responsible for giving other particles mass

Before we dig deeper into the model and the elementary particles it describes, we need to introduce Quantum Field theory.