Light wiki:
>For other uses, see Light (disambiguation). Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. The three basic dimensions of light (i.e., all electromagnetic radiation) are:intensity (or brilliance or amplitude), which is related to the human perception of brightness of the light,frequency (or wavelength), perceived by humans as the color of the light, andpolarization (or angle of vibration), which is not perceptible by humans under ordinary circumstances. Due to wave-particle duality, light simultaneously exhibits properties of both waves and particles. The precise nature of light is one of the key questions of modern physics.
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Button wiki:
>For other uses of the word button, see Button (disambiguation). A button is small disc- or knob-shaped object attached to cloth or an article of clothing. Buttons may be manufactured from an extremely broad variety of materials, including bone, ivory, metal, plastic, and wood. Buttons were first used by the Ancient Romans.The functional role of buttons is to fasten or cinch the openings of a garment. By sliding the button through a slit (the ) in the to which the first is to be held. The slit is only sufficiently wide to allow the button to be fully pushed through while still remaining stitched to the first piece of cloth.
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