Source: NOVA: "Secrets of Lost Empires: Easter Island" This resource was adapted from NOVA: "Secrets of Lost Empires: Easter Island." Archaeological evidence suggests that ancient peoples were able to ...

Most of the talk in the rifle world these days about bullets with high ballistic coefficients, high-magnification trajectory-compensating riflescopes, and rifles guaranteed to deliver one-hole groups.

This interactive activity from the NOVA website challenges users to lift one end of an obelisk to a height of three feet using only a lever, a fulcrum, weights, and some supporting stones. Levers are ...