Johannes Kepler
The German mathematician and astronomer, Johannes Kepler is
remembered chiefly for his discovery that the planets move in elliptical orbits. But he
was also interested in the study of light. In 1604 he published a book called Astronomiae
Pars Optica which explained, with the help of a number of experiments, how light
travelled in straight lines, how it cast shadows, and how it bent when it moved from one
substance to another. Kepler also realised why people with long or short sight cannot see
clearly.
His biggest discovery was discovering light travelled in straight
line, thus causing shadows to be formed. The discovery helps to dismiss that shadow are
ghosts as they can change in sizes after changing distances between the object and light
source.
