Federico Mengozzi

What do we know of the structure of reality?

The Standard Model

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Circles in a Circle - Vassily Kandinsky

As human beings, interested in understanding the world around us, we should at least keep up with the current understating of reality. So let’s explore the most fundamental piece of reality known to mankind up to this point.

The most accurate description of the fundamentals of our reality is described by the Standard Model. It describes the elementary particles that constitute matter. The main distinction is between fermions and bosons.

Fermions are in turns divided into quarks and leptons. Quarks are the fundamental constituents of matter, the three pairs of quarks represent the respective generation of matter: 1st generation of matter is composed of up and down quarks (they form neutrons and protons), the 2nd generation of matter is composed of charm and strange quarks and the 3rd generation of matter is composed of top and bottom quark. The last two pair of quarks are only found in experiment under extreme conditions. Quarks participate in strong interaction (strong nuclear force).

As with quarks, leptons exists in tree pairs. Each pair has a charged particle and the respective neutral particle (neutrino). Electron and electron neutrino are the 1st generation of lepton, the 2nd generation is represented by Muon and Muon neutrino and finally in the 3rd generation we have Tau and Tau neutrino.

The up and down quarks with the electron are the building blocks of the cosmos.

All fermions have their respective anti particle, that are particles with the same mass but opposite physical charge.

These particles interact with each other because of certain forces. There are 4 well know forces: gravity, electromagnetism, weak and strong forces. While gravity is one of the most obvious forces we can observe, it’s not entirely understood how it plays in the quantum realm. The other three are better defined.

Gravity and electromagnetism have a very long range of action. While weak (responsible for certain radioactivity) and strong force are appreciable only at distances much smaller that the size of a proton.

There forces works by exchanging a particular type of particle, the boson. In particular the gluon (actually 8 types of gluons) for the strong force, the photon for the electromagnetic force, and the W and Z boson for the weak force. The last particles of the standard model is the Higgs boson that instead of carrying forces, it gives mass to all the other particles.

For people like us who believe in physics, the separation between

past,

present,

and future

has only the importance of an admittedly tenacious illusion.

Albert Einstein

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