Do you ever wonder how much of what we do you could figure out from scratch? Tying your shoe might seem simple now, but kids have trouble mastering the skill, and dreaming it up for the first time is ...

A very early voltaic pile, the first type of chemical battery. Alternating discs of zinc and copper (each about 2-13/16" diameter) are separated by (now degraded) pads that would have been damped with ...