Dr. John Macadam (May 1827 – 2 September 1865), was an Australian (Scottish-born) chemist, medical teacher and politician. The genus Macadamia was named after him in 1857 by his colleague Ferdinand von Mueller.

Macadam was born in Northbank, near Glasgow, Scotland. He studied chemistry at the Andersonian University and the University of Edinburgh, later switching to medicine at Glasgow. In 1855, he went to Melbourne, where he had been appointed as a lecturer in chemistry and natural science at Scotch College.

On 7 August 1858 he officiated as one of two umpires at a game of football played between Scotch and Melbourne Grammar. This game was a predecessor to the modern game of Australian Rules Football and is commemorated by a statue depicting the game outside the Melbourne Cricket Ground.

In 1858 he was also appointed as the Victorian Government Analytical Chemist. He later became the first lecturer to teach at the University of Melbourne School of Medicine. On 3 March 1862, he commenced lectures in chemistry.

3-2-1 Contact is an American science educational television show that aired on PBS from 1980 to 1988, and an adjoining children's magazine. The show, a production of the Children's Television Workshop, teaches scientific principles and their applications. Dr. Edward G. Atkins, who was responsible for much of the scientific content of the show, felt that the TV program wouldn't replace a classroom but would open the viewers to ask questions about the scientific purpose of things.

3-2-1 Contact was the brainchild of Samuel Y. Gibbon, Jr., who had been the executive producer of The Electric Company for CTW from 1971 to 1977. (Gibbon actually left CTW before Contact's production began, though he was still credited as "Senior Consultant.")

The first season of 65 programs began airing January 14, 1980 on select PBS member stations; it featured a cast of three college students who discussed science in an on-campus room known as the Workshop. The first season came to an end on April 11, 1980, but funds for more episodes were not sufficient until 1982.