Time to go back 13.8 billion years to the instant of the Big Bang. The Big Bang is the leading model of how the Universe began and isn’t debated very widely other than believers of models of Creationism.
With the two pillars of relativity and quantum mechanics, the earliest moment the laws of physics as we know them were measurable was approximately 10 x -37 seconds after the Bang itself. An infinitely tiny number. At this instant, the exponential expansion of the Universe began and is still continuing today. To recap, using relativity we can measure the current outward expansion of the universe and run it backwards until eventually the whole universe is at one single dense point of infinate energy.
At 10 x -6 seconds or one millionth of a second after the Big Bang, the strong nuclear force began to bind positive and negatively charged quarks to form protons and neutrons. The strong nuclear force is the strongest of all forces of nature but it also has the shortest range. Protons have a positive electric charge and neutrons have zero charge as the name suggests. The strong nuclear force is the glue that sticks protons and neutrons to form a nucleus.
Basic science teaches that opposite charges attract and same charges repel. The strong force depends on the exchanging of particles to generate sufficient energy to overcome the repulsion. The exchanging particles are called mesons.
Think of a game of tennis, two players hitting a ball back and forth to one another. If this exchange keeps taking place, the strong force is able to hold these particles together. Without the strong nuclear force we wouldn’t have stars, planets or galaxies as none of the basic or heavier elements would be able to glue together to form the matter we can observe today.
It is important to note that the protons and neutrons must be extremely close together for this force to work, if the distance is too great the repulsion will take effect and the particles won’t be able to bind to one another.
The strong force takes its full effect at one Femtometer, which as a unit of distance is one quadrillionth of a meter. At this distance it is 137 times stronger than the weak nuclear force, a million times stronger than the electromagnetic force and hundreds of quintillions times stronger than gravity.
The energy required to break the strong force and the nucleus apart is enormous, so the energy that is released can and has been used in nuclear weaponry. Sadly, when we go in search of the nature of reality and find the fundamental answers to how the universe works, there always seems to be a way to use this new knowledge to destroy one another.