Visible Light Beams
From the side, a beam of light is only visible if part of the light is scattered by objects: tiny particles like dust, water droplets (mist, fog, rain), hail, snow, or smoke, or larger objects such as birds. If there are many objects in the light path, then it appears as a continuous beam, but if there are only a few objects, then the light is visible as a few individual bright points. In any case, this scattering of light from a beam, and the resultant visibility of a light beam from the side, is known as the Tyndall effect.
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Famous quotes containing the words visible, light and/or beams:
“Men of extraordinary success, in their honest moments, have always sung, Not unto us, not unto us. According to the faith of their times, they have built altars to Fortune, or to Destiny, or to St. Julian. Their success lay in their parallelism to the course of thought, which found in them an unobstructed channel; and the wonders of which they were the visible conductors seemed to their eye their deed.”
—Ralph Waldo Emerson (18031882)
“Ive never been afraid to step out and to reach out and to move out in order to make things happen.”
—Victoria Gray, African American civil rights activist. As quoted in This Little Light of Mine, ch. 3, by Hay Mills (1993)
“The highway presents an interesting study of American roadside advertising. There are signs that turn like windmills; startling signs that resemble crashed airplanes; signs with glass lettering which blaze forth at night when automobile headlight beams strike them; flashing neon signs; signs painted with professional touch; signs crudely lettered and misspelled.... They extol the virtues of ice creams, shoe creams, cold creams;...”
—For the State of Florida, U.S. public relief program (1935-1943)