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.
In the U.S., we often see the stars of the American flagimposed on one corner of the rainbow flag, too. The colors of the rainbow flag continue to influence LGBTQIA iconography around the world, mergingwith older symbols to add to a rich tapestry of history.