In 1983, the metre was redefined in the International System of Units (SI) as the distance travelled by light in vacuum in 1/ 7008299792458000000â 299792458 of a second. As a result, the numerical value of c in metres per second is now fixed exactly by the definition of the metre.
Blattodea is an Order of insects containing the cockroaches. Cockroaches first evolved around 350-300 million years ago and are probably one of the most despised of all insects. For some people the mere mention of cockroaches will send them running for cover.
American rapper GZA wearing a do-rag. A do-rag (also spelled variously as a doo-rag, dew-rag, du-rag or durag), is a hat used to cover the top of one's head, sometimes made of nylon material and having a skullcap fit. It may also be referred to as a wavecap. According to the Oxford English Dictionary and Merriam-Webster dictionary, the term derives from 'do as in hairdo.