There is no scientist named Ham in ham radio. The term was first an insult, like "ham-fisted" (clumsy) or "ham actor" (bad stage actor). Then the radio operators decided to take the name as a source of pride, and found three radio pioneers to say it was named for:
The H is for Heinrich Hertz, who did a lot of work with radio frequency energy and for whom the measurement of frequency is named.
The A is for Major Edwin Armstrong, who invented frequency modulation. Apparently no one else was available because FM wasn't a popular mode in the amateur service when they borrowed his name.
The M is for Guglielmo Marconi, who invented the radio.
The ecology pioneer whose last name begins with Mu is John Muir.
Isaac Newton
Albert Einstein
Albert Einstein of course.
hagiai
cannonball adderly
cranescuckooscrows
Ugli fruit begins with the letter "U".
Elmur Fudd.
There isn't a Harry Potter character whose name begins with Gan.
Alvin
Eragon.