PHYSICAL WORLD — What is Physics? | Understanding The Science Behind Every Action In This Universe

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There is no science in this world like physics...

WHAT IS PHYSICS?

We all love to explore and study physics and its principles. But have you ever wondered what exactly is this "physics" that we keep talking about? We know that there are many laws in physics that define the functioning of nature. Basically physics is about understanding the actions happening in nature. But, the question still arises, what exactly is physics? Is it only about laws and rules? Or is it a subject to study at school and get grades? When we ask such a question as "WHAT" is physics, we basically are trying to understand the significance of physics and what it does in our lives.

We can thus say, that physics is the laws and principles that governs the universe. It tells us why and how things behave the way they do. Also, it helps us to predict the future of things. How? Well, we have made other articles regarding "how" physics actually helps in doing that. Here we are interested in identifying the face of physics and what it really is. Several scientists that we know are great physicists and philosophers. Einstein, Newton, Hawking, Schrodinger, Planck, Bohr and you name it, were all great philosophers as well. Hence, we can also say that physics is a "philosophy". It is the basic laws of nature which explains this physical world.

If you have completed high school, then you know, that physics is incomplete without mathematics. They both go together. Mathematics is also popularly called as the "language" of physics since physics can be seen in application when we have some numbers.

FUNDAMENTAL PRINCIPLES IN PHYSICS

There are two fundamental principles in physics:

1) UNIFICATION

This principle is the attempt to explain various phenomena through a few laws. For example, the free fall of apple (Apple is given respect in physics since it was the reason why gravity was discovered), the motion of planets around the sun, the motion of satellites around planets, etc. These phenomena were unified by a single law given by Isaac Newton, that is, the universal law of gravitation, represented by the equation:
F = (Gm1m2)/r²

Other examples of unification can be the Second Law of Thermodynamics. It simply states that heat flows from a region of higher temperature to a region of lower temperature.

Maxwell's four equations explain the entire electromagnetism. Each equation explains vast topics in physics such as complete electrostatics, complete electrodynamics, complete magnetism and complete electromagnetic waves.

2) REDUCTIONISM

Reductionism is to study a large system and understand the properties of constituent particles. For example, studying about a generator includes the study of magnetism, armature coil, slip rings etc.

SCOPE AND EXCITEMENT IN PHYSICS

SCOPE

There are two scopes in physics:

1) Macroscopic

2) Microscopic

• MACROSCOPIC

Under macroscopic physics, we deal with subjects such as mechanics, thermodynamics, electromagnetism and optics.

Further classifications under these four subjects are also studied which make up macroscopic physics.

Mechanics: Motion, Laws of motion, Work and Energy, Rotational Motion, Gravitation, Properties of solids and fluids (liquids and gases), Oscillatory motion and Wave mechanics (sound properties).

Thermodynamics: Heat, Temperature, Laws of Thermodynamics, Heat Engine, Conduction, Convection and Radiation.

Electromagnetism: Charge, Direct Current, Devices, Magnetism, Electromagnetic Induction, Alternating Current, Electromagnetic Waves.

Optics: Light, Reflection (Mirrors), Refraction (Lenses, Prism) and Devices (Telescope, microscope).

• MICROSCOPIC

Microscopic physics is even more interesting than macroscopic physics since this field has so much to be discovered! It is all about the spooky nature of physics that can not be understood by everyone. It is none other than the world of QUANTUM MECHANICS.

This scope of physics deals with the study of atoms, nuclear physics, nature of electron, nature of some special particles such as photons, elementary particles, semiconductors and a lot more. There is so much to be explored here yet. Today, modern physicists are researching on these subjects to make new discoveries.

EXCITEMENT

Physics is indeed an exciting area to study. Physics helps us in:

• Understanding daily life phenomena.
• Conducting experiments
• Applications
• Future prediction

These points (and more) justify the excitement in physics. And this is just the surface level we're taking about. If we go deeper into physics, it is impossible to come back without having your brain acquire new ways of thinking and perceiving the nature.

PHYSICS AND TECHNOLOGY

#1) New physics gives rise to new technology.

• Silicon chips gave rise to semiconductors which in turn led to the invention of laptop, mobile phones and T.V.
• EM Waves made wireless communication possible.
• Alternating current was achieved by using the principles of electromagnetic induction which was then used to invent transformers and electric generators.

#2) Need of technology gives rise to new physics.

• The steam engine wasn't the best option for travelling, hence a newer and better transportation medium was required. Here, physics came to the rescue and with the concepts of thermodynamics, heat engines and diesel engines were developed for the betterment of the society.

If you think about it, these two points are just the converse of each other. Hence, physics and technology go hand in hand.

FUNDAMENTAL FORCES IN NATURE

There are only FOUR fundamental forces in our universe under which all the forces that you can name, come under. These are:

• Gravitational Force
• Weak Nuclear Force
• Electromagnetic Force
• Strong Nuclear Force

These four forces define the working mechanism of physics. In simple words, these forces are the fuel of physics which run the universe. Let us understand about each force and what differentiates them. We have already explained them in greater detail in this article: The Four Fundamental Forces In The Universe | Physics | Science Specials Week S02 E08. So check out for more.

GRAVITATIONAL FORCE

This is the weakest force in the nature. The concept of gravitation was first proposed by Isaac Newton in 1665. This force acts between ANY two bodies in this universe and is represented by the equation:

F = (Gm1m2)/r²

Gravitation is a long range force, which means it can act between bodies infinitely far away as well. This force does not require any medium to act.

WEAK NUCLEAR FORCE

Another fundamental force, but this force acts between very small particles such as neutrinos and other elementary particles. This force acts between very short ranges as small as 10^-14 m to 10^-15 m. This force is so rare that it can only be seen during Beta decays.

Interesting thing is, this force is stronger than the gravitational force.

ELECTROMAGNETIC FORCE

This force is stronger than both gravitation and weak nuclear force. This force acts between charges. For example, the negative charge of an electron attracts the positive charge of a proton, but repels the negative charge of another electron. This is again a long range force and does not require any medium.

In general, E.M force is considered a strong force which can cause big lightnings and thunderstorms.

STRONG NUCLEAR FORCE

The strongest force in the nature - The Strong Nuclear Force. It acts between particles independent of their charge. For example, it acts between neutron-neutron, proton-neutron and proton-proton. What about electrons? Well, generally, this force has no impact on electrons. Just like weak nuclear force, this force is also a short range force.

This force is the reason why protons stay together in the nucleus even though there is such a strong electromagnetic force pushing themselves away from each other. The neutron applies the strong nuclear force and binds up all the protons together. And as we know now, strong nuclear force is much stronger than electromagnetic force. In fact, it is the strongest of all.

STRENGTH RATIO

Have you wondered "how" strong really is strong nuclear force than the rest of the forces? Well, thanks to the calculations made by the scientists, we have a strength ratio of each force with respect to each other.

So, if we assume the strength of the strong nuclear force to be 1, then the respective strength ratios of other forces will be as follows:

S.N       E.M           W.N      Gravitation

 1        10^-2       10^-13       10^-38

So, this representation clearly shows the power of strong nuclear force. Even though we do not see most of the forces in action in our day to day life, these forces still play an integral role in everyday life. If you think more deeply, you will realise that if there were no such thing as strong nuclear force, then this world would never exist.

This is the entire physical world that we live in. It works on the principles of physics and understanding the nature is the reason why physics came into the picture. This picture will only expand and grow with no limits.