The Sunquest Sundial is a

sundial A sundial is a horology, horological device that tells the time of day (referred to as civil time in modern usage) when direct sunlight shines by the position of the Sun, apparent position of the Sun in the sky. In the narrowest sense of the ...

gnomon A gnomon (; ) is the part of a sundial that casts a shadow. The term is used for a variety of purposes in mathematics and other fields, typically to measure directions, position, or time. History A painted stick dating from 2300 BC that was ...

automatically corrects for the

equation of time The equation of time describes the discrepancy between two kinds of solar time. The two times that differ are the apparent solar time, which directly tracks the diurnal motion of the Sun, and mean solar time, which tracks a theoretical mean Sun ...

allowing it to tell clock time. The Sunquest sundial utilizes a cast aluminum gnomon, the shape of which is related to the

analemma In astronomy, an analemma (; ) is a diagram showing the position of the Sun in the sky as seen from a fixed location on Earth at the same Solar time#Mean solar time, mean solar time over the course of a year. The change of position is a result ...

. When turned to face the sun, the gnomon casts a curved ribbon of sunlight onto the time-scale arc, correcting for mean time. The Sunquest sundial won

Sky & Telescope ''Sky & Telescope'' (''S&T'') is a monthly magazine covering all aspects of amateur and professional astronomy, including what to see in the sky tonight and new findings in astronomy. Other topics covered include: *observing guides for planets, ...

magazine's "Sundial of the Year 2000" competition in 1966. The Sunquest Sundial has been featured in several other publications, including ''Sundials: The Art and Science of Gnomonics'', ''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...

'' and ''Sundials: Their Theory and Construction''.

References

External links

*{{official, http://sunquestsundial.org/ Sundials