As he sailed west, local noon occurred progressively later, until finally, when he had circumnavigated the globe, the shift in local noon time, as measured by his chronometers should be exactly twenty-four hours.
32.
:: The latter is also true if you define " local noon " as " noon according to local mean solar time " without reference to time zones, due to the equation of time.
33.
For instance, although Boston and Philadelphia are in the same time zone, local noon ( when the sun is highest in the sky ) will occur at different times because Philadelphia is maybe 200 miles west of Boston.
34.
The first realistic value was calculated by Alexandrian scientist Eratosthenes about 240 BC . He knew that on the summer solstice at local noon the sun goes through the zenith in the ancient Egyptian city of Syene ( Assuan ).
35.
Solar time is measured by the apparent diurnal motion of the Sun, and local noon in apparent solar time is the moment when the Sun is exactly due south or north ( depending on the observer's latitude and the season ).
36.
Eratosthenes knew that at local noon on the summer solstice in the Ancient Egyptian city of Swenet ( known in ancient Greek as Syene, and now as Aswan ) on the Tropic of Cancer, the sun would appear at the zenith, directly overhead.
37.
The world standard measurements are made by the Dominion Radio Astrophysical Observatory at Penticton, B . C ., Canada and reported once a day at local noon in solar flux units ( 10 " 22 W�m " 2 �Hz " 1 ).
38.
The local noon newscast was moved from KRNV-DT to KRXI-TV on June 1, 2015 to comply with FCC rules stipulating that a company providing more than 15 % of a station's programming per-week would have an " attributable interest " in the station, thus counting as ownership.
39.
References to the Tang's Chronicles ( 618-907 ), at Holing on the day of the summer solstice ( June ), an eight-foot vertical stake of sundial would cast a shadow that was around two feet long at the time of local noon that fell to the south side of the stake.
40.
If you define " local noon " as " 12 : 00 according to the local time zone ", then any place close to the arctic circle and offset far enough from the time zone's meridian can have sunset before noon .-- talk ) 02 : 44, 24 December 2009 ( UTC)
