History of the transistor about 15 volts". Brattain and H. R. Moore made a demonstration to several of their colleagues and managers at Bell Labs on the afternoon of 23 December 1947, often given as the birth date of the transistor. The "PNP point-contact germanium transistor" operated as a speech amplifier with a power gain of 18 in that trial. In 1956 John Bardeen, Walter Houser Brattain, and William Bradford Shockley were honored with the Nobel Prize in Physics "for their researches on semiconductors and their discovery of the transistor effect". Twelve people are mentioned as directly involved in the invention of the transistor
Claes Nobel Claes Nobel Claes Nobel (; ; born 1930), a native of Sweden, is grandson of Ludvig Nobel and grand nephew to Alfred Nobel, who established the Nobel Prizes. Founder of the National Society of High School Scholars, Nobel is an advocate of humanitarian and environmental causes, and was honored at the Artivist Film Festival in November 2007 for his work in these areas. He is also Chief Mentor to Cogent EMR Solutions, a company dedicated to research and development of Electromagnetic Radiation (EMR) safety products and services. In 1974 he drafted The Nobel Laureates Declaration on the Survival of Mankind,