Whispering-gallery wave Whispering-gallery wave Whispering-gallery waves, or whispering-gallery modes, are a type of wave that can travel around a concave surface. Originally discovered for sound waves in the whispering gallery of St Paul’s Cathedral, they can exist for light and for other waves, with important applications in nondestructive testing, lasing, cooling and sensing, as well as in astronomy. Whispering-gallery waves were first explained for the case of St Paul's Cathedral circa 1878 by Lord Rayleigh, who revised a previous misconception that whispers could be heard across the dome but not at any intermediate position. He explained the phenomenon of travelling whispers with
Collection of the National Gallery, London works, see Catalogue of paintings in the National Gallery, London. Collection of the National Gallery, London The National Gallery is the primary British national public art gallery, sited on Trafalgar Square, in central London. It is home to one of the world's greatest collections of Western European paintings. Founded in 1824, from an initial purchase of 36 paintings by the British Government, its collections have since grown to about 2,300 paintings by roughly 750 artists dating from the mid-13th century to 1900, most of which are on display. This page lists some of the highlights of the collection. For the