Evolution: A Scientific American Reader
From the Scopes “Monkey Trial” of 1925 to the court ruling against the Dover Area School Board’s proposed intelligent design curriculum in 2005, few scientific topics have engendered as much controversy—or grabbed as many headlines—as evolution. And since the debate shows no signs of abating, there is perhaps no better time to step back and ask: What is evolution? Defined as the gradual process by which something changes into a different and usually more complex and efficient form, evolution explains the formation of the universe, the nature of viruses, and the emergence of humans. A first-rate summary of the actual science of evolution, this Scientific American reader is a timely collection that gives readers an opportunity to consider evolution’s impact in various settings.
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Astronomers are not sure, for example, how the galaxies were formed, but there is no reason to think the process did not occur within the framework of the big bang. Indeed, the predictions of the theory have survived all tests to date.
To test Hubble's law, astronomers need to measure distances to galaxies. One method for gauging distance is to observe the apparent brightness of a galaxy. If one galaxy is four times fainter in the night sky than an otherwise ...
... the age of the universe decreases to the range of seven to 13 billion years. To improve these estimates, many astronomers are involved in intensive research to measure both the distances to galaxies and the density of ...
Workers in laboratories have derived these age estimates from atomic and nuclear physics. It is noteworthy that their results agree, at least approximately, with the age that astronomers have derived by measuring cosmic expansion.
Astronomers have studied this radiation in great detail using the Cosmic Background Explorer (COBE) satellite and a number of rocket- launched, balloon-borne and ground-based experiments. The cosmic background radiation has two ...
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Dinosaurs and Other Monsters