Lynde, Carleton John, b. 1872, Gilbert, Alfred C. (Alfred Carlton), 1884-1961 · New Haven, Conn. : A.C. Gilbert Co. · leaf 18
f sight; the rays are notreal, they are imaginary, straight lines which give the directionof the light and they are always at right angles to the waves. Parallel Waves and Rays. The waves from the dot are largerthe farther they are from the center, and when they are one hun-dred yards or a mile… … and since the rays are always at rightangles to the waves they are also nearlyparallel. This is particularly true if thedistant point is the sun, at a distance ofninety million miles. Parallel waves andrays then are those from a distant source.Beam. Pencil. A beam (Fig. 15) is a group of parallel…
Light · Scientific recreations
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