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
Nobel Prize controversies stated, should be given "to the person who shall have made the most important 'discovery' or 'invention' within the field of physics". Awards committees have historically rewarded discoveries over inventions: 77% of Nobel Prizes in physics have been given to discoveries, compared with only 23% to inventions. In addition, the scientific prizes typically reward contributions over an entire career rather than a single year. No Nobel Prize was established for mathematics and many other scientific and cultural fields. An early theory that jealousy led Nobel to omit a prize to mathematician Gösta Mittag-Leffler was refuted because of timing inaccuracies. Another