Oracle bone shows a once-shorter day
"Three flames ate the sun. Big stars [seen]."
These cryptic words, inscribed in Chinese characters on an ancient piece of tortoise shell, record a total solar eclipse in which the sun's corona and its streamers became visible and stars appeared in the sky. They also give a way of determining the Earth's rotation rate thousands of years ago.
In an ingenious piece of astronomical and historical detective work, Kevin D. Pang of the Jet Propulsion Laboratory in Pasadena, Calif., and his collaborators pinpointed the eclipse date: June 5, 1302 B.C. In turn, they deduced that a day is now 0.047 second longer.