Willebrord Snellius was born in 1580.

Willebrord Snellius died in 1626.

The Dutch astronomer, Willebrord Snellius, calculated pi to 35 decimal places in the early 17th Century.

The first recorded theory about the rainbow phenomenon was formulated by Noah, who interpreted it as a sign of God's acceptance of his offering. The rainbow can be represented mathematically in terms of Snell's law (Willebrord Snellius) and the Fresnel boundary equations.

Rudolph Snellius died in 1613.