These all come in many colors: some are a very intense red some have a weak, pale flame some have a bright light some pulsate some are a uniform yellow with no discharges or rays emerging… The sky is seen to burn, the glow of which is occasionally so high it may be seen amongst the stars themselves, sometimes so near the ground that it assumes the form of distant fire. Like a crown encircling the inner part of the fiery sky, there is a recess like the open mouth of a cave… A stretch of the sky seems to have receded and, gaping open, displays flames deep down. An even more detailed depiction comes to us from Seneca, also captive to the lower latitudes his whole life, who described the northern lights in his Natural Questions, calling them Chasmata - chasms, rifts, gapings - of the sky: More than two millennia earlier, despite never having traveled far enough north from his Mediterranean home to witness this spectacle of the higher latitudes, Aristotle had described the phenomenon in his book on meteorology. (Available as a print and as stationery cards.) Aurora Borealis by Étienne Léopold Trouvelot, 1872. Scientists knew of only one phenomenon in nature that corresponds to this pattern: the Aurora Borealis. It came in waves of varying intensity all throughout the evening, interpolating between positive and negative current with each wave. Lightning storms and other electrical disturbances were a known interference - a current of normal electricity would emit a bright spark while passing from the stylus to the moistened paper, but it would not set it aflame and would produce no color. The early telegraph was an electro-chemical technology that used a current passing through chemically coated paper to record a message from a faraway station. ![]() The current then subsided as gradually as it came on, until it entirely disappeared, and was then succeeded by a negative current, which bleached instead of colored, the paper this also gradually increased, until, as with the positive current, it burned the paper, and then subsided, to be followed by the positive current. The paper was set on fire by the flame, and produced considerable smoke. On the evening of February 19, 1852, a scientist at the New Haven station of the nascent telegraph witnessed something extraordinary:Ī blue line appeared upon the paper, which gradually grew darker and larger, until a flame of fire followed the pen, and burned through a dozen thicknesses of the prepared paper.
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