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*World of Mathematics* on Willebrord Snell

Willebrord Snell is best known for his discovery regarding the refraction of **light** rays. This discovery, known as Snell's law, demonstrates that when a ray of light passes from a thinner element such as air, into a denser element, such as water or glass, the **angle** of the ray bends to the vertical. Snell's law--a key revelation in the science of optics--was formulated after much experimentation in 1621. This is expressed as sin *i *=* *sin *r *(i=angle of incidence, r=angle of refraction and * *= a constant). However, he did not publish his findings, and the law did not appear in print until **René Descartes** discussed it (without giving Snell credit) in his *Dioptrique* in 1637. Snell also determined a formula to measure distances using trigonometric triangulation. His method, developed in 1615, used his home and the spires of Leiden churches as reference points. (In 1960, a plaque recognizing his work...

This section contains 906 words(approx. 4 pages at 300 words per page) |