"The strong and weak forces are less familiar because their strength rapidly diminishes over all but subatomic distance scales; they are the s. This is why these two forces were discovered only much more recently. The strong force is responsible for keeping quarks "glued" together inside of protons and neutrons and keeping protons and neutrons tightly crammed together inside atomic nuclei. The weak force is best known for the radioactive decay of substances such as uranium and cobalt."