c**i
发帖数: 6973 | 1 (1) Amir D Aczel, An Expedition Without End; Battling subzero temperatures,
swarming mosquitoes and angry Inquisitors, all to find a single number. Wall
Street Journal, June 27, 2011
http://online.wsj.com/article/SB10001424052
702304186404576387761564776914.html
(book review on Larrie D. Ferreiro, Measure of the Earth; The Enlightenment
Expedition that Reshaped the World. Basic Books, 2011)
Quote: "But Newton's recently published theory of mechanics indicated that a
spinning Earth would look more like an apple, wider at the equator and
flatter at the poles. Since the Earth's rotation is most pronounced at the
equator, that part of the globe bulges the most—for the same reason that if
you swing around a weight tied to a rubber band, the band will expand. Thus
a degree of latitude there is smaller, in actual north-to-south distance,
than a degree closer to one of the poles. (If the Earth were a perfect
sphere, a degree of latitude would be everywhere equal.)
My comment: I did not know the eartyh is not a perfect sphere.
(a) Shape and Size of the Earth. Center for Aerospace Education, Windward
Community College, University of Hawaii, undated.
http://aerospace.wcc.hawaii.edu/shape.html
* Mauna Kea
http://en.wikipedia.org/wiki/Mauna_Kea
(in Hawaii island; 4,205 m (13,796 ft) above sea level, its peak is the
highest point in the state of Hawaii. However, much of the mountain is under
water; when measured from its oceanic base, Mauna Kea is over 10,000 m (33,
000 ft) tall—significantly taller than Mount Everest./ In Hawaiian, Mauna
Kea means "white mountain",[32] a reference to its summit, which is usually
snow-capped in winter)
(b) Definition and measurement of latitude:
"Latitude and longitude are angular measures: latitude tells us the angle to
which a point is elevated above the plane of the equator, as measured from
the center of the Earth; longitude tells us how far east or west of the
prime meridian a point is (Figure 8). Note that while the equator is
naturally defined by the Earth’s rotation, the prime meridian is arbitrary,
so we must agree on a prime meridian before we can interpret the
coordinates we are given."
Isaac Kunen, Introduction to Spatial Coordinate Systems: Flat Maps for a
Round Planet. SQL Server Technical Article, July, 2008.
http://msdn.microsoft.com/en-us/library/cc749633(v=sql.100).asp
(c)
"If the earth were a perfect sphere (which it isn’t), the distance, or the
length, of 1o of latitude would be constant everywhere. In reality, the
earth is slightly flattened at the poles, so the length of 1o of latitude at
the poles is slightly more than at the equator. At the equator, the length
of 1o of latitude is equal to 110.6 km (68.7 mi.) and at the poles, the
length of 1o of latitude is equal to 111.7 km (69.4 mi.). For our purposes,
we will assume the length of one degree of latitude is 111 km."
Latitude and Longitude Getting Started. Digital Mobile Map, Oct
http://www.digitalmobilemap.com/latitude-and-longitude-getting-
Note:
(a) geodesy (n; Greek geōdaisia, from geō- ge- + daiesthai to divide):
"a branch of applied mathematics concerned with the determination of the
size and shape of the earth and the exact positions of points on its surface
and with the description of variations of its gravity field"
(b) expedient (n): "something done or used to achieve a particular end
usually quickly or temporarily"
(c) colonial (n): "a member or inhabitant of a colony"
, which, I may add, is exactly the same as "colonist."
All definitions are from www.m-w.com. | c**i
发帖数: 6973 | 2 (2) Adam Barrows, Time Wars; How a huge new clock in Mecca is reviving a
century-old clash over what time it is. Boston Globe, June 19, 2011
http://articles.boston.com/2011-06-19/bostonglobe
/29677482_1_largest-clock-prime-meridian-greenwich-royal-observatory
("What we all accept as the global standard for time dates back to a meeting
held just 127 years ago: the 1884 International Meridian Conference, which
was convened not in England but right here in the United States [at
Washington DC]. In the course of the proceedings, representatives from 24 '
civilized' nations selected the longitudinal meridian passing through the
Greenwich Royal Observatory as the world’s prime meridian, from which time
in all nations would be calculated.")
Note:
(a) Greenwich Mean Time is the mean solar time at the Royal Observatory in
Greenwich, London.
I have tried hard to comprehend "mean solar time" but failed.
(b) Universal Time Coordinated (UTC) is based on Time, Atomic International
(French: Temp Atomique International; TAI) with leap seconds added at
irregular intervals to synchronize with the Earth's rotation. UTC is closely
related to Universal Time and Greenwich Mean Time (GMT) and within informal
or casual contexts where sub-second precision is not required, it can be
used interchangeably). Wikipedia.
* Why is UTC the Preferred Acronym?
http://www.timeanddate.com/time/utc-abbreviation.html
(c) Dunsink
http://en.wikipedia.org/wiki/Dunsink
(d) geographer (n): "a specialist in geography"
(e) Chester Arthur (1829-1886; US president 1881–1885; Republican)
(f) The article stated, "In Ireland, Dublin continued until World War I to
observe two times: a Greenwich-based time for its seaport and a Dunsink-
based time for all its city clocks."
Republic of Ireland
http://en.wikipedia.org/wiki/Republic_of_Ireland
(table: Independence from the United Kingdom
- Declared 24 April 1916
- Ratified 21 January 1919
- Recognised 6 December 1922)
(g) daylight saving time
http://en.wikipedia.org/wiki/Daylight_saving_time
(Starting on 30 April 1916, Germany and its World War I allies were the
first to use DST (ger.: Sommerzeit) as a way to conserve coal during wartime
. Britain, most of its allies, and many European neutrals soon followed suit
. Russia and a few other countries waited until the next year and the United
States adopted it in 1918.)
(h) For "Royal Hotel Clock Tower," see Abraj Al Bait Towers
http://en.wikipedia.org/wiki/Abraj_Al_Bait_Towers
(also known as the Mecca Royal Hotel Clock Tower) |
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