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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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Proving Copernicus Right
3 March 1997 7:00 pm
The name of 16th century Polish astronomer Nicolaus Copernicus became a household world because he proposed that the Earth revolves around the sun. But the man who finally gathered scientific proof of that theory was English astronomer James Bradley, born during this month in 1693.
Called the best astronomer in Europe by Isaac Newton, Bradley methodically observed the star Gamma Draconis and noticed slight seasonal shifts in its position, which he then observed in other stars as well. He called this effect "the aberration of light" and estimated its angle at 20 to 20.5 seconds; the modern value is 20.47 seconds. Eventually, Bradley realized that the displacement stemmed from viewing a stationary object from a moving one, the Earth--thus confirming Copernicus's concept.
Bradley later discovered a second process that causes stars to wobble in their places in the firmament. In an effect he called "nutation"--known to be true today--subtle changes in the angle of Earth's rotation, caused by the moon's pull on the equator, alter apparent stellar positions.