fundamental forces, with the shortest range of all. It holds the quarks together within protons and neutrons, and holds the protons and neutrons together to form atoms.
thermodynamics: The branch of physics concerned with heat and the other forms of energy.
uncertainty principle: One can never be exactly sure of both the position and the velocity of a particle; the more accurately one knows the one, the less accurately one can know the other.
virtual particle: In quantum mechanics, a particle that can never be directly detected, but whose existence does have measurable effects.
