Whispering-gallery wave known as surface plasmons has been demonstrated in the form of whispering-gallery waves, and likewise for exciton-polaritons in semiconductors. Galleries simultaneously containing both acoustic and optical whispering-gallery waves have also been made, exhibiting very strong mode coupling and coherent effects. Hybrid solid-fluid-optical whispering-gallery structures have been observed as well. 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,
Collection of 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 list of all named painters in the collection and their