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Transcript of RAINBOWS
He presumed that the rainbow was caused by reflection of sunlight in the clouds. The light was reflected at a certain angle. That means the rainbow consists of a cone of rays. Aristotle was thus the first to explain the rainbow's circular shape and that the rainbow is not located at a definite place on the sky, but is seen in a certain direction.
Seneca the Younger
a Roman philosopher had two theories: one, that the rainbow is produced by the sun reflecting in each water-drop, the other, that it is produced by the sun reflected in a cloud shaped like a concave mirror.
Descartes' 1637 treatise, Discourse on Method, further advanced this explanation. Knowing that the size of raindrops did not appear to affect the observed rainbow, he experimented with passing rays of light through a large glass sphere filled with water.
Isaac Newton demonstrated that white light was composed of the light of all the colors of the rainbow, which a glass prism could separate into the full spectrum of colors, rejecting the theory that the colors were produced by a modification of white light.
The Karens, a group of people in Burma, once considered rainbows to be dangerous demonic spirits that devoured the souls of humans and caused sudden or violent deaths. They thought that such activity made the rainbow thirsty enough to appear in the sky and dip down to Earth to drink water.
There was a belief among ancient Polynesians that a rainbow was a ladder that their heroes climbed to reach heaven.
The folklore of ancient Greece taught that Iris, wife of the god Zephyrus, caused rainbows. Iris was a messenger between mortals and the gods. She ran back and forth, dressed in shimmering multicolored robes. The word "iridescence" comes from Iris's robes.
optical-operating in or employing the visible part of the electromagnetic spectrum.
phenomenon -a fact or situation that is observed to exist or happen, esp. one whose cause or explanation is in question.
Why the colors?
Sunlight is made up of many wavelengths—or colors—of light. Some of those wavelengths get bent more than others when the light enters the water droplet. Violet (the shortest wavelength of visible light) bends the most, red (the longest wavelength of visible light) bends the least. So when the light exits the water droplet, it is separated into all its wavelengths. The light reflecting back to you, the observer with the Sunlight coming from behind you, from the water droplets will appear separated into all the colors of the rainbow! Violet will be on the bottom and red on the top.
Rainbows are both refraction and reflection
Types of Waves
A rainbow is both transverse and longitudinal