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How does the strong force hold protons and neutrons together in atomic nuclei?

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A diagram of a cylindrical vessel containing gas, with a movable piston held down by a weight. Countless small dots beneath the piston represent gas particles in rapid, random motion, illustrating Bernoulli's model of gas pressure. — physics As conceived by Daniel Bernoulli in *Hydrodynamica* (1738), gases consist of numerous particles in rapid random motion. He assumed that the pressure of a gas is produced by the direct impact of the particles on the walls of the container.

The strong force is a fundamental interaction that acts as the "glue" holding the atomic nucleus together, overcoming the repulsive electromagnetic force between positively charged protons.123

This force originates from a property called colour, which is analogous to electric charge. While protons and neutrons are themselves colourless, they are composed of quarks that possess colour charge. The strong force operates by the exchange of massless messenger particles known as gluons between these quarks.24

Key characteristics of this interaction include:
* Short Range: The force is effective only over extremely short distances, roughly the diameter of a proton or neutron ( $10^{- 15}$ meters).12
* Confinement: Because gluons themselves carry colour charge, they interact with each other. This causes the force to increase with distance, effectively locking quarks inside baryons like protons and neutrons.2
* Quantum Chromodynamics: This quantum field theory describes how these interactions maintain the stability of matter by ensuring that only colourless combinations of quarks can exist.2