By 300 BC, Greek scholars had begun to study and contemplate optical phenomena generating theories to explain vision, color, light, and astronomical phenomena. Many of those theories turned out to be wrong, but they did serve to inaugurate the science of optics.
During the second century AD, Ptolemy, a Greek astronomer based in Alexandria, Egypt, studied and wrote about many topics in science. He published five books about optics, but only one book has survived to the modern era. This series of works was dedicated to the study of color, reflection, refraction, and mirrors of various shapes.
Few other advances were made in optics until after 1000 AD. The Arab scholar Alhazan, a.k.a. Abu Ali Hasan Ibn al-Haitham, conducted the first serious study of lenses in Basra (Iraq). He studied refraction in lenses, and also carried out research on reflections from spherical and parabolic mirrors. His writings were the first to explain vision correctly, as a phenomenon of light coming into the eye, rather than the eye emitting light rays.
Roger Bacon, an English philosopher from the 13th century, postulated, but could not demonstrate, that the colors of a rainbow are due to the reflection and refraction of sunlight through individual raindrops.
NOTE: The term “light” is often extended to adjacent wavelength ranges that the eye cannot detect - to infrared radiation, which has a frequency less than that of visible light, and to ultraviolet radiation, which have a frequency greater than that of visible light. This is the attitude employed by the editors of this page.
Newton’s Prism Experiments
After moving the screen and achieving a beautiful spectrum he did his crucial experiment to prove that the prism was not colouring the light. He put a screen in the way of his spectrum, and this screen had a slit cut in it, and only let the green light go through.
Then he put a second prism in the way of the green light. If it was the prism that was colouring the light, the green should come out a different colour. The pure green light remained green, unaffected by the second prism.
In another Experiment, after getting a spectrum with his prism, he placed another prism upside-down in the way of the light spectrum after passing the first prism. The band of colors combined again into white sunlight. For a demonstration of this experiment click here.
In these experiments, Newton had proved that white light was made up of colors mixed together, and the prism merely separated them - he was the first person to understand the rainbow.
To repeat Newton's experiments check out the following links:
Optics - Jose Wudka
Newton and the Colour of Light - The College of Optometrists, London
Newton´s Prism Experiment With Light - KSU Physics Education Research Group
Newton's Blue Light Experiment - Florida State University
Prism - Eric Weisstein's World of Physics
Newton’s Prism Experiments and Theory of Color - Ether Wave Propaganda
Newton’s Prism Experiment and Goethe’s Objections - Gernot Hoffmann
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Edison Thomas 1
Edison Thomas 2
Galileo Galilei 1
Galileo Galilei 2
Joule, James Prescott
Leonardo da Vinci
Pavlov & Skinner
Pitch Drop Experiment
Spectrum of Light
|Scientists & Inventors||Science Jokes||Warning!|