Atmospheric optics wavelengths. A halo (ἅλως; also known as a nimbus, icebow or gloriole) is an optical phenomenon produced by the interaction of light from the sun or moon with ice crystals in the atmosphere, resulting in colored or white arcs, rings or spots in the sky. Many halos are positioned near the sun or moon, but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air. There are many types of ice halos. They are produced
What Is Art? to justify their own tastes. Jahn notes the "often confusing use of categorisation" and the lack of definition of the key concept of emotion. Bayley writes that "the effectiveness of "What is Art?" lies not so much in its positive assertions as in its rejection of much that was taken for granted in the aesthetic theories of the time". Noyes criticises Tolstoy's dismissal of beauty, but states that, "despite its shortcomings", "What is Art?" "may be pronounced the most stimulating critical work of our time". Simmons mentions the "occasional brilliant passages" along with the "repetition, awkward language, and loose terminology".