Ca. 11,000 BCE – Ca. 7,500 – 5,000 Years Ago Ca. 150-250 CE – 1730s 1887 1893 1902 1909 1911 1929 1947 1948 1994 2007 2008 Clovis phase [..]

The standard unit used to measure the strength of an electrical current.

Electric current in which the electrons periodically and rapidly change direction.

A tool used by prehistoric hunters to throw projectile weapons such as spears and darts. It consisted of a long, hollowed-out rod made from bone or wood, with a hook at one end and a handle at the oth [..]

The most basic unit comprising matter. Atoms consist of electrons, protons and neutrons.

Extinct form of wild ox believed by archaeologists to have been first domesticated in Asia and Europe by around 6,000 BCE.

Two or more cells connected together to store electricity.

Diesel fuel made from biomass.

Any energy derived from biological sources.

Any fuel derived from a biomass, such as wood or ethanol.