This ruler lists people who have made important contributions in any number of scientific disciplines: Medicine, Astronomy, Physics, Chemistry, Mathematics, Biology, Psychology, to name just a few. We have tried to find individuals whose contributions were important to mankind, and who came from various time periods, regions of the world and educational backgrounds.

As you read through the list of names, you might notice several familiar terms. The wordsFahrenheit(as in temperature),voltandampere(electricity),daguerreotype(photography),Morse(like the telegraph code) andpasteurizationall come from the names of scientists on the ruler.

Many of these women and men have earned a Nobel prize. That prize is also named after a scientist,Alfred Nobel(1833-1896).

The dates listed are the years of each scientists birth and death, if known. Weve done our best to summarize in a single word or phrase the most important aspect of their career.