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How Do Rainbows Form When Sunlight Meets Raindrops?
阳光遇到雨滴时，彩虹是怎样形成的？
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Rainbows appear when sunlight enters spherical raindrops, bends, reflects inside, and exits.
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White light separates into colors because each wavelength bends by a slightly different amount.
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Red light bends least and exits at about 42 degrees; violet bends most and exits near 40 degrees.
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Your eye sees only one color from each drop, depending on its position in the sky.
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Millions of drops together create the full arc, with red always on the outer edge.
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You must stand with your back to the sun and rain in front to see a rainbow clearly.
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Double rainbows occur when light reflects twice inside a drop, reversing color order.
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The secondary bow is fainter because more light escapes after the second bounce.
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No two people ever see the exact same rainbow, since it depends on their unique viewpoint.
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This natural prism effect reveals how light and water interact to produce beauty and science.