Willebrord Snell was a great scientist, mathematician, and astronomer. He had many great accomplishments in his lifetime.

Willebrord Snell was born in Leiden, Netherlands, in 1580. He attended the University of Leiden where he studied law. However, he wanted to work with mathematics and he even taught math while he studied law. He was able to give mathematics lectures at Leiden on special days. He graduated with his degree in 1607.(1)

Rudolph Snell, his father, was the professor of mathematics at Leiden. When he died in 1613, Willebrord took over the position of professor at the University of Leiden. Snell worked a lot with mathematics and optics but also with astronomy and navigation. He worked with comets in the navigation field and he published Tiphys Batavus for navigation. (1 & 2)

Snell contributed to the science of optics when, in 1621, he discovered the basic law of refraction. (4) Refraction is the bending of waves caused by a change in their speed when they move from one medium to another. However, it did not become known until 1703 when Huygens published Dioptrica which included Snell's discovery. (1) Other major accomplishments include Eratosthenes Batavus, which was a way of measuring earth by triangulations and would eventually become the foundation of modern geodesy(2); and improving "pi" estimation, by using a 96 sided polygon. Snell also worked with loxodrome, the path on the sphere that makes constant angle with the meridians. (3)

Willebrord van Roijen Snell died at the age of 46 in Leiden, Netherlands on October 30, 1626. He had stayed  and did all his studies in the Netherlands. Although he didn't have a very long life span he contributed a lot to the science of optics and mathematics.