Take the bundle of spaghetti of spaghetti in one hand, place it vertically in the pot with boiling water, push down on the bundle from the top with your other hand. As the bottom part heats up and moistens the spaghetti will become immediately pliable and start going down and spreading out (in an appealingly geometric fashion), within a matter of seconds. You could cook 10" spaghetti, whole, in a 5" diameter pot with no problems.