A modern sundial at Parkes radio astronomy observatory, New South Wales, Australia. This sundial is unusual in that it include the so-called Equation of Time, which indicates the error caused by the Earth's motion around the Sun. Wavy lines are printed on the surface of the dial with months markers at the top end, showing where to read the shadow cast by the gnomon. Markers are spaced at 10 minute intervals, so the time reading can be fairly precise.

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Size: 5128px × 3408px
Location:
Photo credit: © MARK WILLIAMSON/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: astronomy, australia., clock, correction, dial, earth, equation, error, gnomon, graph, indicator, modern, motion, observatory, parkes, precise, precision, radio, season, shadow, south, sun, sundial, time, timepiece, unusual, wales