The journey of physics starts as the most complex subject in the entire universe. It is one which is still far from being completely understood, one that is the literal cause of everything.

**Classifying the discipline into further it has-**

**Classical physics**– It says the objects will move if one kick them. Or if one hits anything it will hit them back with the same force. Each and everything attracts the entire universe towards them with a force that is inversely proportional to the distance.

**The next typical concept is that of electromagnetism-**

Thanks to it, our gadgets work and more magnificently the universe exist because of it. It describes how electric and magnetic fields, which are as a whole the same thing, actually work. If we try to summarize it briefly, it means the motion of electrons and photons.

**Another important concept is that of thermodynamics-**

It tries to explain the heat and energy of the whole universe and says how entropy tends to get higher that can result to inevitable death of the entire universe, the phenomena is known as heat death

Fluid dynamics is another excruciating hard way of determining how aerodynamic a particle can be.

One main question that students often ask is,

How to** enter the expression 2cos2** (**Î¸)****-1, where**** Î¸**** is the lowercase Greek letter theta?**

The answer to which is Cos (2Î¸).

Solution is something like this,

2cos2 (Î¸)-1 = 2cos2 (Î¸) â€“ {cos2 (Î¸) + sin2 (Î¸)} = {cos2 (Î¸) â€“ sin2 (Î¸)} = cos2 (Î¸)

Another important concept is that of optics that explains how behaves when it passes through glass. Along with this, physics have relativity as a big pillar of its study. As per Sir Albert Einstein, speed of light is constant, 299792459 m/s to be precise.

He explained the theory of relativity with the equation, E = mc^{2}

He also explained that gravity is not a force; rather it is the curvature of space-time itself. Talking about quantum mechanics which is another crucial topics that students face difficulty apart from finding the answer to the question, How to** enter the expression 2cos2** (**Î¸)****-1, where**** Î¸**** is the lowercase Greek letter theta?**

The standard model of quantum mechanics says that there are at least 13 types of elementary particles.

- Fermions
- 6 types of quarks
- 6 types of leptons
- 4 types of gauge bosons
- One scalar boson

Coming to the super string theory, it replaces all the elementary particles with very tiny vibrating strings. It also explains that different particles have different vibrations. It also argues that there are eleven special dimensions and not just three.

Then we have the Heisenbergâ€™s uncertainty principle, which states that one can not physically determine both the position and the momentum of a quantum particle at the same time.

Physics is the subject of theories and that pretty much explains everything right with anti-matter, dark-matter, back-holes matter, quantum gravity, the big bang, the infinite universe that is still expanding and last but not the least the Pythagoras theorem.