We humans have a funny way of naming things, especially when it comes to the world of astrophysics. Subatomic particles called quarks are classified into ‘flavors’ when they cannot be tasted at all. The process of falling into a black hole that causes an object to be stretched in a particular direction due to the strong effects of gravity is termed ‘spaghettification’. Get it? Because a black hole stretches an object like a spaghetti noodle. The Big Bang theory seems to imply from its name that the Universe began with an explosion or a ‘bang’ when in reality it was more of a rapid expansion of the Universe from a point sized singularity. So it came of no surprise when the discovery of the Higgs Boson in 2012 led it to be nicknamed as ‘The God Particle’ even though it did not prove whether God or anything supernatural actually existed. But before we get ahead of ourselves, let us understand what the Higgs Boson i.e. the so-called God Particle actually is.
the Standard Model
In simple terms, the Higgs Boson is responsible for giving the property of mass to certain kinds of particles. To understand how this is possible, we need to take a detour into Quantum Field Theory and what is known as The Standard Model. The Standard Model of particle physics as it is better known, is the best theory we currently have which describes the four fundamental forces and elementary particles that make up this Universe. Elementary particles i.e. those particles that cannot be further divided into constituents, are classified into various groups as shown below.
This table can be thought of as the periodic table of elementary particles. As you can see, there are 3 groups: quarks, leptons and gauge bosons. You may even by excited to see the Higgs Boson in there, but one step at a time!!
I wont be going very deep into how each particle behaves but just to summarize, the quarks are what make up protons and neutrons. The proton is made up of two up quarks and one down quark whereas the neutron is made of one up quark and two down quarks. Protons, neutrons and electrons then combine to form the atoms we all know. The other quarks make up other kinds of exotic particles but that does not concern us. If you notice, you can even see the peculiar naming we talked about earlier in the names of the quarks.
The leptons on the other hand consists of the familiar electron and its more massive cousins. Finally we have the gauge bosons which are responsible for mediating three of the four fundamental forces of nature. The photon is responsible for electromagnetism, the gluon for the strong nuclear force while the W and Z bosons mediate the weak nuclear force. Gravity being the fourth fundamental force cannot be described by quantum mechanics yet and to solve this problem has been one of the greatest challenges in physics for over a century!!
But we are going off topic. If you did not understand the last paragraph, that does not matter. The most important thing to know for the matters of this post is how each particle shown here is described by Quantum Field Theory (QFT).
Quantum Field Theory
In QFT every elementary particle is thought to have an associated ‘field’. You can think of this field as a set of values assigned to each point in space. Just like an electric field which denotes the strength and direction of an electric field at any point. The field for a particle is something similar. The physical meaning of a field is debatable but it will suffice us to know that each field has an associated energy and when there is a large fluctuation in this energy in some area, we see it as a particle. For example, the electrons we talk about are actually fluctuations of an ‘electron field’ which permeates all of space.
You can think of this field as a calm sea where tiny ripples in some parts of the sea are thought of as particles. Please note however that this field we talk about is not some physical substance like the water that makes up the sea. Rather it is an abstract mathematical construct whose physical meaning is not well known yet. Its a tough concept to wrap our brains around but every elementary particle that makes up the matter in the Universe is on the most fundamental scale, just a fluctuation of an associated field. However from a macroscopic viewpoint like ours, an electron seems to behave like a solid particle would. And what is even more interesting is the fact that particles can interact with fields of other particles as well!!
The HIGGS BOSON
This is where the Higgs Boson comes in. As you might have already guessed, the Higgs Boson has its own field known as the Higgs Field. The interaction of this field with certain particles is what is ultimately responsible for giving them the property of ‘mass’. Although the math behind this is very complex, we can intuitively understand how this might happen with an analogy of a spoon in a honey syrup. When we try to stir a spoon in honey, we feel a resistive force on the spoon exerted by the viscosity of the honey. The honey which is analogous to the Higgs Field, interacts with the spoon which can be thought of as a particle to give it some inertia or ‘mass’. Some particles interact more with this field that others causing different masses for different particles.
You might have noticed however that I mentioned that the Higgs Field gives the property of mass to only ‘certain’ particles. By ‘certain’ I mean the particles such as W and Z bosons, charged leptons and quarks. If these names frighten you, don’t worry. All you need to know is that not all particles acquire their mass from the Higgs Field. Some particles like photons, the particles of light, are massless i.e. they do not interact with the Higgs Field at all whereas particles like protons and neutrons (which are not elementary as they are made up of quarks) acquire mass through other processes which are beyond the scope of this post.
The discovery of the Higgs Boson was a big breakthrough in physics as it now gave an explanation to why particles have mass at all. However, the existence of this boson was predicted way back in 1964 by British particle physicist Peter Higgs but we had no experimental evidence of its existence till 2012.
Here is a photo of him standing beside the CERN Particle Accelerator in Geneva, Switzerland where this discovery was made. Higgs would eventually go on to win the Noble Prize in Physics “for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles”.
So Why God Particle?
The bottom line of all this is that the Higgs Bosons (the particles) are just a fluctuations in the Higgs Field which interacts with certain particles and gives them the property of mass. So why is it called ‘The God Particle’? That is because of a book called surprise-surprise, ‘The God Particle’, written by Nobel Prize winning physicist Leon Lederman in 1993. At the time of writing the Higgs Boson was not discovered yet. The book by Leon Lederman covers the various advances in particle physics that had occurred up to that point and explains why the Higgs Boson’s discovery could revolutionize physics which it eventually did in 2012.
He gives a reason for nicknaming this particle, ‘The God Particle’ in his book as follows,
“This boson is so central to the state of physics today, so crucial to our final understanding of the structure of matter, yet so elusive, that I have given it a nickname: the God Particle. Why God Particle? Two reasons. One, the publisher wouldn’t let us call it the Goddamn Particle, though that might be a more appropriate title, given its villainous nature and the expense it is causing. And two, there is a connection, of sorts, to another book, a much older one…”
So we see that the naming of this particle was just the sense of cheeky humor of physicists at work just like the other funny names we saw at the beginning of this post. However, sometimes these names are taken out of context and may mislead people into believing something about a scientific discovery that is false. Something similar happened when the nickname of ‘God Particle’ was overused by newspaper articles to achieve clickbait titles, so much so that some people actually started believing the Higgs Boson to be evidence for the existence of God when nothing could be further from the truth.
Due to this, the term ‘God Particle’ is heavily criticized in the scientific community, with one of the biggest critics being Peter Higgs himself. So remember, the next time you hear the term ‘The God Particle’ or any other fancy names being used in newspaper headlines to report a scientific discovery, always take it with a pinch of salt!