<human>:  Who invented the transistor and when?
<bot>: That would be John Bardeen, Walter Brattain, and William Shockley. The transistor was invented in 1947, and it has been an important component of the modern electronics industry ever since. The transistor is a small electronic device that can amplify and switch electronic signals. It is used in many applications, including amplifiers, radios, and televisions.