Why Time and Longitude? -- Flamsteed House, Royal Observatory, Greenwich, London, UK
N 51° 28.679 W 000° 00.122
30U E 708176 N 5707243
An interpretive sign inside Flamsteed House explains the interplay between time and longitude
Waymark Code: WMT46Q
Location: London, United Kingdom
Date Posted: 09/22/2016
Views: 1
The Time and Longitude exhibit at Flamsteed house is DEFINITELY worth a visit at the Royal Observatory in Greenwich. The exhibit traces the challenges of navigation in the 15th century that gave rise to incredible scientific and technological innovations in the 15th through 19th centuries, leading directly to the rise of Britain as a maritime superpower and imperial superpower.
This historic plaque in the exhibit reads as follows:
"WHY TIME AND LONGITUDE?
The earth makes one full 360° turn each day. If we divide this rotation is 24 hours, each hour-long division of time, represents a 15° segment of longitude (east-west). Every degree of longitude gives 4 min. of local time difference.
If you know the variation in local time between two places on earth, you immediately know the longitude between them. The five hour time difference tween Greenwich and New York represents about 75° of longitude.
Measuring your local time at sea is fairly easy. The difficulty lies in knowing the local time back home. There are two ways to solve this problem.
One ways to carry “home time” with you on an accurate clock, set before the ship parts. Another way is to use the sky is a clock, measuring the position of the sun, moon and stars to calculate both your local time and your ”home time.”"
Type of Historic Marker: Interpretive sign
Historical Marker Issuing Authority: Royal Museums Greenwich
Age/Event Date: 01/01/1500
Related Website: [Web Link]
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