Rainbow flag India during the week of Amartithi (the anniversary of his death on January 31, 1969). Rainbow is used as an element of flag of Patriots of Russia (Russian: Патриоты России, "Patrioty Rossii") political party. This rainbow flag in Italy was first used in a peace march in 1961, inspired by similar multi-coloured flags used in demonstrations against nuclear weapons. It became popular with the "Pace da tutti i balconi" ("peace from every balcony") campaign in 2002, started as a protest against the impending war in Iraq. The most common variety has seven colours, purple, blue, azure, green, yellow, orange and
Rainbow in his model. As he noted in his "Kitab Tanqih al-Manazir" ("The Revision of the Optics"), al-Farisi used a large clear vessel of glass in the shape of a sphere, which was filled with water, in order to have an experimental large-scale model of a rain drop. He then placed this model within a camera obscura that has a controlled aperture for the introduction of light. He projected light unto the sphere and ultimately deduced through several trials and detailed observations of reflections and refractions of light that the colours of the rainbow are phenomena of the decomposition of light.