WILLEBRORD SNELL
(1580-1626) |
 |
Willebrord Snell was an early seventeenth
century Dutch mathematician who is best known for his discovery of refraction.
He was born in 1580 in a place called Lieden. Snell began to study math
at a very young age as he was very interested in it. his father, Rudolph
Snell, was a professor of mathematics at Leiden.
Willebrord entered the university of Leiden
at a young age where he originally studied law. Not long after, he turned
his attention towards math and started teaching at the university by the
time he was 20. After finishing with a degree, he traveled to eastern Europe
and visited most of the famous astronomers today.
In 1613, Snell succeeded his father as professor
of mathematics. In 1617, he published "Eratosthenes Batavus", which explained
his methodology for measuring the earth by triangulation. Snell had difficulty
in finishing the book, however , he got help to finish it.
Willebrord also improved the classical method
of calculating approximate values of ¶ (pi) by polygons. His method
of using 96 sided polygons gave the correct value of ¶ (pi) up to
7 places while the classical method only gave 2 correct places.
Snell published other books, including his
work on comets and in 1624 he published "Tiphys Batavus". This piece of
work was on navigational theories.
Although Snell discovered the law of refraction,
he didn't publish it. He discovered this in 1621 and only in 1703 did it
become known when "Huygens" published his results in "Dioptrica".
Willebrord's biggest contribution to science,
however, is the law of refraction, even though it wasn't published until
almost 70 years after he died. He found that a beam of light would bend
as it enters a block of glass, and that the angle of bending would depend
on the angle of the light beam. Light traveling perpendicular to the glass
will not bend, however, if the light travels at an angle into the glass
it will bend to a degree proportional to the angle of inclination.
In 1621, Snell found a characteristic ratio
between the angle of incidence and the angle of refraction. His law demonstrates
that all substances have a specific bending ratio or "refractive index".
This law can be described by the following formula:
n1 sin < = n2 sin <
In this equation, n is represented by the refractive
indices of material 1 and material 2 and are the angles
of light traveling through these materials.
From this equation we can tell that if n1
is
greater than n2, the angle refraction is always smaller than
the angle of incidence. Also, when the two refractive indices are equal
then the light is passed through without refraction.
Willebrord van Roijen Snell died at the young
age of 46 on the 30 of October in 1626. He would never realize how important
his discovery was and how famous he would become because he only became
famous 70 years after he died
Works Cited
.
1. Molecular
Expressions: Science, optics, and you-timeline-Willebrord Snell
http://micro.magnet.fsu.edu/optics/timeline/people/snell
2. Molecular
Expressions Microscopy Primer: Light and Color-Refraction of Light
http://micro.magnet.fsu.edu/primer/lightandcolor/refraction.html