Celestial theory of natural spectacle
China Daily | Updated: 2009-07-22 07:55
PARIS: Total solar eclipses have struck awe or fear into hearts for millennia, but scientists are more interested in the unusual mathematics behind the gold-and-indigo lightshow.
A remarkable act of celestial geometry explains it all.
When the moon glides between Earth and the sun, it casts a cone-shaped shadow, called an umbra, that races from West to East.
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