No-bake energy balls rolled in popped amaranth, with a long note on the science of how grains pop (expand): each grain has a little moisture inside; when heated rapidly at high temperature the moisture turns to steam; since the hard outer shell traps it, pressure builds until the shell bursts and the steam escapes with great speed, giving the grain an impulse (mass times velocity) so popcorn flies everywhere. Because the core reaches a high enough temperature, the inside is cooked and the popped grain is soft, crunchy and edible. This process is called expansion. Rules for popping (expanding) anything: 1) you need grains with a hard shell and a little moisture inside; 2) you need a pot with a lid and a strong burner; 3) heat the pot very well, add the grains, put the lid on (remember the impulse) and watch; 4) a glass-lid pot is best so you can see inside; if the burner is too strong the shell can scorch and become porous so no pressure builds; 5) suitable grains for home expansion are popcorn corn, amaranth and wild rice.