What is Matter made of? Standard Model of Elementary Particles explained.

What is this all made of?  What is the fundamental building block of this universe? These kinds of questions have bugged many great thinkers for hundreds of years. In this blog, let us discuss the most updated model humans have come up with to answer this fundamental question i.e. what is all this made of?

Technically, if you modify this question, then it would be something like, what is all 'matter' made of? In ancient cultures, this substance should be individual (Cannot be further divided) And they called it an atom (derived from the Greek word atomos, meaning uncuttable). But further studies discovered that this atom can be further divided and thus the discovery of subatomic particles, electrons, neutrons, and protons was established. For a short period of time, these were considered as indivisible particles. But this understanding was put into question by Murray Gell-Mann in his 'Quark theory'. This theory was further developed, and currently, we have 'The Standard Model of particle physics'. Trying to answer that same fundamental question. What is all matter made of?

Then considered indivisible particle atom is made of a dense nucleus and a field of electrons surrounding the nucleus. Electron is one of the elementary particles (Elementary being one of the building blocks of matter). The nucleus consists of protons and neutrons, these two are not elementary particles, but they consist of Quarks. Proton consists of 2 up-quarks and 1 down-quark. And neutron consists of 2 down-quarks and 1 up-quark. Quarks are elementary particles. 'Electron neutrino' is another almost massless elementary particle, which is created during the fusion process in stars. These four elementary particles 

1. Electron 
2. Up quark 
3. Down quark and 
4. Electron neutrino 

makes up all the ordinary matter that we experience in our daily lives. These four elementary particles hold the entire first column of the standard model of elementary particles table. Other elementary particles are rare and don't exist in our ordinary matter. They are only created in 'particle accelerators' like the Hadron Collider in Geneva or, when cosmic rays hit the atoms of Earth's atmosphere in special conditions.

4 Elementary particles responsible for all the Ordinary Matter

The standard model table divides elementary particles into three types 

1. Fermions 
2. gauge bosons 
3. scalar bosons.

Fermions are matter-particles or in other words, fermions are the ones that make up the matter. Gauge bosons are force-carrying particles. Guage bosons are responsible for the three fundamental forces Strong force, electromagnetic force. and weak force. Scalar bosons is a Higgs boson that is responsible for the mass of particles when they interact with the Higgs boson field.

Fermions; Fermions are further divided into two types quarks and leptons. What is the difference between the two? quarks interact with the elementary particle that is responsible for strong force. Whereas leptons do not interact with this particle (discussed further in the blog). Quarks are of six types

• up
• down 
• charred
• strange 
• top
• bottom

Leptons are of six types. 

• Electron
• Muon
• Tau 

Muon and Tau are the heavier siblings of Electrons with almost the same properties. 

• Electron Neutrino
• Muon Neutrino 
• Tau Nutrino.

These three are called Nutrinos in general, and are the lightest of mass-having particles These interact with other particles only by interacting with the weak force.

Standard Model of Elementary Particles 

Gauge Bosons: There are four different gauge bosons.

1. Gluons: It is the force carrier that carries strong force. Strong force is a force that is responsible for binding the neutrons and protons inside the nucleus. These are massless force carriers. Quarks interact with the elementary particle Gluon which is responsible for strong force. Whereas leptons do not interact with Gluon.

2. Photons: It is the force carrier that carries electromagnetic force responsible for all electrical and magnetic forces of the universe. Light is an electromagnetic wave consisting of photons. These are massless force carriers.

3. W-Boson and Z-Boson. These force carriers are responsible for the weak force of the universe. Week force is the reason behind radioactive decay and other radiation.

Scalar Bosons. There is one scalar boson Higgs Boson. Higgs Boson is more likely a field than a particle. Higgs boson gives mass to the particle that interacts with this field.

Interaction of Elementary Particles

This is the basic overview of all elementary particles known to humankind till now. But wait, where is gravity here? This is where this 'Standard model of elementary particles' has its major limitations. Gravity, one of the fundamental forces is not part of this model. There are many reasons, one is because the best understanding that we have about gravity is from relativity. It says gravity is not a force, rather, it is the curvature of space-time fabric itself. Also, this model does not talk about dark matter and dark energy, which comprises 95% of the universe.

Limitations of standard model of elementary particles, How do these particles interact with each other? What is the theory of everything? How relativity and the quantum world be integrated? Answers to these questions will be addressed in future blogs.