Rainbow flag number of non-cooperative groups led to confusion in several countries around the world. Another variation of rainbow flag is used by Jewish Autonomous Oblast, situated in the Far Eastern Federal District of Russia, by the Chinese border. Proportions 2:3. Adopted first of October 1996. The Jewish Autonomous Oblast has a flag with a seven-colour rainbow. The number of colours is meant to symbolize the seven-branched Jewish Menorah. The rainbow flag was popularized as a symbol of the gay community by San Francisco artist Gilbert Baker in 1978. The different colors are often associated with "diversity" in the gay community (but
Rainbow In Europe, Ibn al-Haytham's "Book of Optics" was translated into Latin and studied by Robert Grosseteste. His work on light was continued by Roger Bacon, who wrote in his "Opus Majus" of 1268 about experiments with light shining through crystals and water droplets showing the colours of the rainbow. In addition, Bacon was the first to calculate the angular size of the rainbow. He stated that the rainbow summit can not appear higher than 42° above the horizon. Theodoric of Freiberg is known to have given an accurate theoretical explanation of both the primary and secondary rainbows in 1307. He