HISTORY
My topic is Total Internal Reflection.
In my project, Snell's Law takes a major part because its the only formula that we can use to find the critical angle. Willebrord Snell is the founder of the Snell's Law. He was born in the Netherlands. He was born in 1580 and past away in 1626.
Critical angle
The critical angle is the angle of incidence above which total internal reflection occurs. The angle of incidence is measured with respect to the normal at the refractive boundary. The angle have to be larger than the critical angle in order for the light to refract and reflect. The critical angle is measured by the Snell's law.
For example in this picture, the light hits the water and it refracts and reflects in between the water to wherever it flows. This is because light is invisible in normal air, it is not seen unless there is smoke in air or other objects. light beam refracts and reflects when it hits water, glass, or and other objects.
The history of light goes pretty back to circa 4.5 billion bc. Albert Einstein first explained the theory of stimulated emission of laser in 1917. It became the basis of laser.
A german philosopher, Immanuel Kant's hypothesis was that the sun was a molten glow, and when the temperature increased to millions degrees, and the sun was born and started to shine. Our sun converts 657 million tons of hydrogen into 653 tons of helium every second. A greek philosopher Aristotle discovered that light travels in waves. Hero of Alexandria, also a greek scientist, he was the first to conclude light reflection. Leonardo Da Vinci, an italian scientist was an excellent painter, he studied light and reflection of lights. Jones Inigo, an english architect, later in his life became the master of lighting in his productions. the microscope was invented in 1590 by Zacharias Janssen, he is from Holland. Walgenstein Thomas, was first to work with projection device. He worked in Rome in 1650 with the projector device. Franklin Benjamin, an American who invented Bifocals. He was a critic on the corpuscular theory of light. William herschel discovered that the sun contains more than just invisible colors. Thomas Edison invented the lightbulb in late 1850s. Peggy clark is an American stage lighting designer.
bibliography
http://www.electricalfacts.com/Neca/Science/light/history.shtml
http://library.thinkquest.org/C006027/html-ver/hist-back.html
http://inventors.about.com/od/lstartinventions/a/laser.htm
http://www.mts.net/~william5/history/hol.htm