Ozone layer an altitude of 100 kilometers from the planet's surface. The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in 1930. Ozone in the Earth's stratosphere is created by ultraviolet light striking ordinary oxygen molecules containing two oxygen atoms (O), splitting them into individual oxygen atoms (atomic oxygen); the atomic oxygen then combines with unbroken O to create ozone, O. The ozone molecule is unstable (although, in the stratosphere, long-lived) and when ultraviolet light hits ozone it splits into a molecule of O and an individual atom of oxygen, a continuing process
The Layer Quaternity The Layer Quaternity The Layer Quaternity are four marble sculpture figurines approximately in height located on the two columns of the Layer Monument, an early 17th-century polychrome mural monument () which was installed in the Church of Saint John the Baptist, Maddermarket, Norwich to the memory of Christopher Layer (1531–1600). The quartet of figurines sculptured in marble, "Pax, Gloria, Vanity, Labor" exhibit primary thematic concerns and stylistic attributes of Northern Mannerist art, namely, portraiture of animated human movement, variety and multiplicity, often set in the Classical or mythological world, and inclined towards esoteric concepts. The Layer Quaternity ("circa" 1598–1604) share