The definition of the meter (m), which is the international unit of length, was once defined by a physical artifact - two marks inscribes on a bar of platinum-iridium. Today, the meter (m) is defined in terms of constant of nature: the length of the path traveled by the light in vacuum during a time interval of 1/299, 792, 458 of a second. The Length - Evolution from Measurement Standard to a Fundamental Constant explains the evolution of the definition of the meter.
Rainbow flag (LGBT movement) For other uses, see rainbow flag. The rainbow flag is a symbol of lesbian, gay, bisexual, and transgender (LGBT) pride and LGBT social movements in use since the 1970s. LGBT symbols. The rainbow flag, commonly the gay pride flag and LGBT pride flag, is a symbol of lesbian, gay, bisexual, and transgender (LGBT) pride and LGBT social movements.
The flag was originally created with eight colors, but pink and turquoise were removed for production purposes, and since 1979 it has consisted of six colored stripes. It is most commonly flown with the red stripe on top, as the colors appear in a natural rainbow.he choice of the rainbow in the form of a flag harkens back to the rainbow as a symbol of biblical promise. According to the Bible, God first created the rainbow as a sign to Noah that there would never again be a world-wide flood, also known as the Rainbow covenant.