Everybody knows that stars twinkle, but no one is sure what makes them do it. Some scientists say that small irregularities in the air act like tiny lenses and make the stars seem to vibrate to & fro. Others think the twinkling is in the eye. Because the pinpoint star-images can cover only a few of the light-sensitive receptors in the eye's retina at a time, the slightest movement makes the star seem to jump and twinkle as the image moves from one group of receptors to another.
Astronomers, who do most of their observing with photography, have no answer to the...
To continue reading:
or
Log-In
