Nature of the forces

The fundamental forces 

The four fundamental forces of nature govern the working of the universe and the phenomena taking place in it, These forces are associated with a force particle (or bosons) in particle physics, The strong nuclear, Electromagnetic, Weak nuclear, and Gravitational force (a force particle associated with the gravitational force hasn't been observed yet; Dated this blog- 19 October 2021)

Strong Nuclear Force

The Strong nuclear force as the name suggests is the strongest force in nature and is associated with Gluon as its force particle, Briefly; this is the force that holds protons in an atomic nucleus together canceling the repulsion between them (also known as the Coulomb force) in a simple nucleus of two protons the repulsion between them is 9 kg force, 9 kg force is not a great deal in the macro world but in the quantum realm it's a huge amount of force; to scale it up if two protons are that close to each other (10^-27 meters) they'll move away from each other with a speed of 13,000 kilometer/second relative to each other. The clearly strong nuclear force is far greater than the Coulomb force because it not only has to cancel the repulsive electrostatic force but also holds these particles together. This is the reason harnessing the energy of an atomic nucleus by the means of nuclear fission reaction requires a lot of energy itself as it is equivalent to breaking the gluon force and at the same time it releases a lot of energy too as energy is always conserved but can be transformed. Despite being the strongest force the strong nuclear force has a short-range hence in a nuclear fusion reaction we have to put up unexplainable amounts of energy to overcome the coulomb force and reasonable enough it is not yet possible on Earth, Although the sun does it repeatedly transforming hydrogen to helium continuously releasing a massive 3.84x10^26 jouls of energy per second in the form of heat and electromagnetic radiation out of which a really tiny fraction reaches on earth. 

Electromagnetic Force

The electromagnetic force is the second strongest force, predictably enough it's a hundred times weaker than the strong force; the Coulomb force is also a component of the electromagnetic force, Despite having a weaker strength electromagnetic force has a longer range than the strong force. We often come across sentences like "like charges repel and opposite charges attract" but how do they actually do so? yes, there is electricity involved in it and positively charged particle attracts negatively charged particle and repels other positively charged particle but, how does an electron know of the other charged particle has the same charge or the opposite or even if it does have a charge or not; Charged particles emit short-lived photons and this is how they communicate- Electromagnetic force is the force through which charged particles communicate. The matter is 99.99999% empty space ever wondered why we don't pass through solids? It's the electromagnetic repulsions that prevent it and hold us up against the gravitational pull of our planet. 

Weak Nuclear Force

The weak nuclear force is associated with W and Z bosons and is a million times weaker than the strong force, The weak force is the only force that cares about the chirality of the particles, Chirality is the 'spin' of the particles, In quantum mechanics, particles can be described as wave functions too so if two particles that have same chirality are superimposed on each other it would create a destructive interference or even nullify the wave function this is the reason it is said that two particles with the same spin cannot be present in the same shell. A monumental discovery about a peculiar property of the weak force was made by a female Chinese experimental physicist Chien Shiung Wu and two male theoretical physicists Tsung Dao Lee and Chen Ning Yang. Although only the theoretical physicist received Nobel prize either because the Nobel committee was had a biased opinion towards theoretical physicists or because Lee and Yang were male; Anyway, Wu did so by placing cobalt 60 which would eventually decay into nickel 60 due to the weak forces releasing an electron and an antineutrino, She did this by placing cobalt 60 in a really strong magnet to align the spin of cobalt 60, Cobalt 60 has a spin of 5 and since spin is always conserved the net spin must be 5 after any type of interaction, Nickle 60 has a spin of 4 and both antineutrino and electron have a spin of 1/2 so, 1/2+1/2+4=5 the spin here is hence conserved. In the electron-antineutrino pairs that are produced electron can either be left-handed chiral or right-handed chiral and the antineutrino will be of the opposite chirality to that of the electron, if the weak force didn't care about the spin of the particle electrons-antineutrino pair with right-handed electron and left-handed antineutrino will be produced in the same amount as electron-antineutrino pair with left-handed electron and right-handed neutrino but the results were fascinatingly different from this- only electrons with right-handed chirality were observed and since antineutrino will always be in the opposite direction it had left-handed chirality. The peculiar property mentioned earlier that originated from Wu's experiment was that "The weak nuclear force interacts with particles that possess right-handed chirality and antiparticles that possess left-handed chirality".

Since W and Z bosons are the particles associated with the weak force it must have some role to play in the weak interactions and decay before that; some caveats, every boson including the Higgs boson is neutral except the W boson it has a charge of +1 or -1, the heavier quarks are said to be unstable because they quickly degrade or decay into the stabler and less heavy quarks. They do so by emitting W boson of any charge such that the charges are conserved. For example- A top quark decays into a bottom quark emitting a W boson which decays into a charm quark then into a strange quark then an up quark, in each degradation a W boson is released that further degrades into a particle-antiparticle pair, this up quark can turn into a down quark and this transformation is reversible- Down quark turning back into an up quark can be dome by absorbing a W boson, The same things happen in unstable isotopes of radioactive elements the quarks inside the nucleons absorb or emit a W boson and turn into the other nucleon (proton to a neutron, neutron to a proton) making the atom more unstable this is also known as a beta decay

Gravity

Gravity is the weakest force it is around Undecillion times weaker than the strong force that is 10^36 or 1 followed by 36 zeros, A particle associated with the gravitational force hasn't been observed although it has been observed that gravity travels in form of waves across the universe this was found out by the Laser Interferometer Gravitational-wave Observatory or LIGO which is the worlds second biggest vacuum chamber with the finest mirrors suspended by silica threads on one of its every end of 2 km arm perpendicular to each other with a laser that uses about 1 megawatt of electricity and with an accuracy 1/10 of the size of a proton. Gravity can be imagined to be ripples in the space-time fabric and since things in quantum mechanics tend to possess a wave-particle duality a particle associated with gravity might exist, its purely hypothetical existence is termed as 'Graviton'.

Gravity being a fundamental force amazes my mind it can be imagined to be a function of the curvature in the fabric of space-time done by the massive objects and the pull experienced on earth is more of the earth itself accelerating with 9.8 ms^-2 across space. the standard model has no place for gravity probably because it has no effect in the quantum realm yet having a name coined for its associated particle hints that scientists believe that it might possibly exist.

Unification of the forces 

Unifying the fundamental forces would revolutionize our current understanding of physics and would even lead to new models of understanding of the universe, unifying electromagnetic and weak forces is successful to a great extent and eventual unification would lead us to a 'Grand unified field theory.