The humble transistor, which transformed the world of electronics and made the age of pervasive computing possible, is 60 years old. 

The first transistor – the size of a mobile phone – was first revealed in December 1947 by Bell Labs scientists John Bardeen and Walter Brattain.
At that stage, computers still used vacuum tubes, but these would be replaced by transistors within a decade.
The technology has come on in leaps and bounds during the 60 years since its invention: the latest Intel microprocessor contains 820-million transistors.
The first commecial products to use transistors were hearing aids, followed by the transistor radion in 1954. The IBM PC was launched in 1981.