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But the universe, all of it, almost everywhere, is 99 percent hydrogen and helium,* the two simplest elements. Helium, in fact, was detected on the S… - Carl Sagan
" "But the universe, all of it, almost everywhere, is 99 percent hydrogen and helium,* the two simplest elements. Helium, in fact, was detected on the Sun before it was found on the Earth — hence its name (from Helios, one of the Greek sun gods). Might the other chemical elements have somehow evolved from hydrogen and helium? To balance the electrical repulsion, pieces of nuclear matter would have to be brought very close together so that the short-range nuclear forces are engaged. This can happen only at very high temperatures where the particles are moving so fast that the repulsive force does not have time to act — temperatures of tens of millions of degrees. In nature, such high temperatures and attendant high pressures are common only in the insides of the stars.
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About Carl Sagan
Carl Edward Sagan (9 November 1934 – 20 December 1996) was an American astronomer, planetary scientist, cosmologist, astrophysicist, astrobiologist, author, and science communicator. His best known scientific contribution is research on extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation. Sagan assembled the first physical messages sent into space, the Pioneer plaque and the Voyager Golden Record, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the hypothesis, accepted since, that the high surface temperatures of Venus can be attributed to, and calculated using, the greenhouse effect. He testified to the US Congress in 1985 that the greenhouse effect will change the earth's climate system.
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Also Known As
Native Name:
Carl Edward Sagan
Alternative Names:
Sagan
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Carl E. Sagan
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Carl E Sagan
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C. E. Sagan
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C.E. Sagan
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C E Sagan
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C. Sagan
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C Sagan
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Sagan C
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Sagan C.
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Sagan C. E.
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Sagan CE
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Additional quotes by Carl Sagan
A scientist places an ad in a Paris newspaper offering a free horoscope. He receives about 150 replies, each, as requested, detailing a place and time of birth. Every respondent is then sent the identical horoscope, along with a questionnaire asking how accurate the horoscope had been. Ninety-four per cent of the respondents (and 90 per cent of their families and friends) reply that they were at least recognizable in the horoscope. However, the horoscope was drawn up for a French serial killer. If an astrologer can get this far without even meeting his subjects, think how well someone sensitive to human nuances and not overly scrupulous might do.
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