FUNDAMENTAL FORCES

Ever since life originated on Earth, all living organisms have gazed upon the night sky and wondered in awe, as to what lies beyond the horizon. From the time humans came into existence, there have been countless theories and speculations about the never-ending space.

To unlock the mysteries of the universe one must have an understanding of how all things in existence interact. To understand this we need to know about the fundamental forces. Up to now, science has confirmed the existence of 4 fundamental forces in nature. These are – Gravity, Electromagnetism, Weak Interaction and Strong Interaction, forces.

(Photo: Google pics)

Gravity is the force of attraction between objects having mass. The existence of gravity had been suspected by Aryabhata and Brahmagupta, however, it was much later that the works of Galileo Galilei and Sir Isaac Newton gave a much better understanding of the force. Much later Albert Einstein proposed General Relativity which indicates gravity not as a force but as the curvature of space itself.

Gravity as proposed by Newton
(Photo: Google pics)

Gravity as proposed by Einstein(Photo: Google pics)

Electromagnetism is the combination of Electricity and Magnetism. Electricity is the interaction between electrically charged objects (positive and negative), whereas magnetism the force that works between magnetic poles (north and south). Though they seem different, one can lead to the formation of others. That is the reason why they are coupled as electromagnetism. The one to reveal this and relate these two was James Clerk Maxwell. Also, it is seen that like charges (and magnetic poles) repel each other while unlike charges (and magnetic poles) attract each other.

Electromagnetic waves(Photo: Google pics)

Electromagnetic spectrum(Photo: Google pics)

Next is the Strong Interaction or Strong Nuclear Force that acts at subatomic levels and is the reason for which the protons and neutrons are tightly packed into the nucleus. The Weak Interaction or Weak Nuclear Force is a force that acts at subatomic levels too. The weak force is the reason behind radioactive decay and hence nuclear fission. Since these forces work at such a small scale, scientists couldn’t discover them. We know that a nucleus of an atom consists of positively charged protons. So according to electromagnetism, the nucleus should be blown off by the repulsive forces. However, that is not the case. Observations like these and theories by many like James Chadwick, Eugene Wigner, Enrico Fermi, etc. prove their existence.

Depicting Strong Forces(Photo: Google pics)

Weak Forces as a cause of fission(Photo: Google pics)

When talking about these forces it is common intuition to wonder which one of them is strongest. At first, it may seem that Gravity is the strongest. But contrary to what seems, it is the weakest. Gravity “seems” strong if you consider the heavenly bodies. But let us consider a few facts. Try lifting an object near to you, your cell phone, pen, a cup of tea, anything. Feel something?? We know that Earth’s gravity acts on all objects. So despite the entire Earth pulling at your cell phone, you are easily able to lift it without any effort as such. That alone explains how weak gravity is. Also, we do not experience electromagnetism on a bigger scale because everything we see around us is electrically neutral (because atoms themselves are neutral). If large scale objects had electric charges on them, the world as we see wouldn’t be the same. These and many other facts give us a conclusion about the strength of the fundamental forces. The strongest being the Strong Nuclear Force followed by Electromagnetism, Weak Nuclear Force and Gravity, respectively.

~ Devraj Roy

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