Fundamental forces

In physics, fundamental forces cannot be explained through simpler or more elementary interactions, so are regarded as fundamental building blocks of the natural world.

The four fundamental forces that account for all the forms of pulling and pushing between things are:

Gravitational force
  • Gravity is the phenomenon that attracts objects with mass or energy towards one another. It affects celestial bodies such as planets, stars, galaxies, and even light. The influence of gravity on smaller objects like human beings in the presence of larger ones, such as planets, is evident. Gravity, such as the Moon’s gravity, leads to ocean tides on Earth. Gravity accounts for the weight of physical objects. Its range is infinite, although its effects weaken as objects move farther apart.
Weak Nuclear force
  • In nuclear physics and particle physics, the weak nuclear force mediates interactions between subatomic particles and is responsible for radioactive decay in atoms. The weak nuclear force doesn’t affect electromagnetic radiation.
Strong Nuclear force
  • The strong nuclear force binds matter together and is responsible for holding together protons and neutrons which are the subatomic particles within the atomic nucleus. It counteracts repulsive electromagnetic forces that push subatomic particles apart but only operate over the smallest imaginable distances. The strong nuclear force plays a central role in storing the energy that is used in nuclear power and nuclear weapons.
Electromagnetic force
  • The electromagnetic force is the interaction that arises between electrically charged particles, such as electrons and is characterized by positive or negative charges. Oppositely charged particles exert an attractive force, while particles with the same charge exert a repulsive force. Photons carry electromagnetic force through electric and magnetic fields, propagating at the speed of light.
  • Whenever there is a push-pull interaction between two objects, forces are exerted on both of them. Once the interaction ceases, the forces no longer act, and the momentum of the objects continues unchanged.
  • On a macro-scale, concentrated matter in celestial bodies like planets, stars, and galaxies leads to significant push-pull interactions.
  • Everything everywhere is in motion. Nothing in the whole Universe is stationary unless its temperature is reduced to absolute zero. In reality, nothing can be cooled to exactly absolute zero.
  • Objects, bodies, matter, particles, radiation, and space-time are all in motion. The concept of motion also applies to the movement of images, shapes, and boundaries.
  • Motion signifies a change in the position of the elements of a physical system including translational motion, rotational motion, vibrational motion, and oscillatory motion.