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A short history of nearly everythingSince Nobel Prizes are never awarded posthumously, longevity can be as important a factor as ingenuity for prizewinners. 18 How c came to be the symbol for the speed of light is something of a mystery, but David Bodanis suggests it probably came from the Latin celeritas, meaning swiftness. The relevant volume of the Oxford English Dictionary, compiled a decade before EinsteinБЂ™s theory, recognizes c as a symbol for many things, from carbon to cricket, but makes no mention of it as a symbol for light or swiftness. 19 Named for Johann Christian Doppler, an Austrian physicist, who first noticed the effect in 1842. Briefly, what happens is that as a moving object approaches a stationary one its sound waves become bunched up as they cram up against whatever device is receiving them (your ears, say), just as you would expect of anything that is being pushed from behind toward an immobile object. This bunching is perceived by the listener as a kind of pinched and elevated sound (the yee). As the sound source passes, the sound waves spread out and lengthen, causing the pitch to drop abruptly (the yummm). 20 The name comes from the same Cavendishes who produced Henry ...» |
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