1 Johannes Kepler : His grandfather was a mayor and his father was a mercenary. When he was six his mother took him to see a comet, and later in his life he almost became a minister, but became an Astronomer instead.
2 Galileo Galilei : His father, who lived from 1564 to 1642, was a talented musician. He wanted to become a priest but his father convinced him to be a physician. Galileo, on accident, took a class on geometry and got interested in astronomy and math.
3 John Napier : He was born in Edinburgh, Scotland in 1550. He entered the University at 13 and got interested in theology. His greatest achievement was inventing the logarithm.
4 The Slide Rule : Napier’s book was a table full of logarithms. The Slide Rule was invented in 1630. The Slide Rule makes it easier to multiply and divide. The middle strip of it slides out between the top and bottom strips.
Stuff That Jack Built 