
Distances of Interest
This thread is for people to post distances and or space measurements from life and art.
I often find when I'm setting a scale or reading a map that I'd like a rule of thumb for what the numbers mean. This is for posting what you think is significant. If we can I'd like to keep this thread on target. If not we'll have to collect any posts at the end.
Sigurd.

House keeping
Basics:
1 mile = 1.609 km
1 km = 0.6214 miles
Acre  One acre comprises 4,840 square yards or 43,560 square feet (which can be easily remembered as 44,000 square feet, less 1%). Because of alternative definitions of a yard or a foot, the exact size of an acre also varies slightly. Originally, an acre was a selion of land one furlong long and one chain wide. However, an acre is a measure of area, and has no particular width, length or shape.
Wikipedia
Chain  A chain is a unit of length; it measures 66 feet or or 22 yards (20.1168m). There are 10 chains in a furlong, and 80 chains in one statute mile. An acre is the area of 10 square chains (that is, an area of one chain by one furlong). The chain has been used for several centuries in England and in some other countries influenced by British practice.
Wikipedia
Furlong  A furlong is a measure of distance in imperial units and U.S. customary units. It is equal to oneeighth of a mile or 660 feet or 201.168 metres.
Five furlongs are approximately 1 kilometre (1.00584 km to be exact). Since the original definition of the metre was onequarter of one tenmillionth of the circumference of the Earth (along the great circle coincident with the meridian of Longitude passing through Paris), the circumference of the Earth is about 40,000 km or about 200,000 furlongs.
Wikipedia  Roman Origins
Hectare  A hectare (symbol ha, pronounced /ˈhɛktɛər/) is a unit of area equal to 10,000 square metres, or one square hectometre, and commonly used for measuring land area. A 100 m square is one ha. Its base unit, the are, was defined by older forms of the metric system, but is no longer part of the modern metric system. The Comité International des Poids et Mesures classifies the hectare as a unit that is accepted for use with SI.
Wikipedia  Metric & Imperial
League  A league is a unit of length or area long common in Europe and Latin America, although no longer an official unit in any nation. The league most frequently expresses the distance a person, or a horse, can walk in 1 hour of time (usually about 3.5 miles or 5.5 kilometres).
Wikipedia (also info on Roman Measurements)

Chain  Sixtysix feet. Ten chains to the furlong, and 80 chains to the mile.

Middle Earth
These measurements are taken from this map which is clear but perhaps not authoritative. If someone has a better source post or PM me.
All measurements are straight distance, as the crow flies.
Brandywine Bridge to Mount Doom
= 333.6 Leagues
= 1167.7 Miles
= 1835 Km
Minas Tirith to Minas Morgul
= 18.7 Leagues
= 65.5 Miles
= 102.85 Km
Edoras to Minas Tirith
= 98.2 Leagues
= 343.7 Miles
= 540.1 Km

Real World
The island of Great Britain encompassing England, Scotland and Wales  80,820 sq.mi
Kansas  81,820 sq. mi.
Minnesota  79,620 sq. mi.
World Factbook  Includes 2008 est pop
Prince Edward Island  2,195 SQ MI , 5,683.91
139,089 residents (Wikipedia 2008 )
Wikipedia  PEI
Gibraltar  2.642 sq mi, 6.5 sq. km.
Pop: 28,875 (Wikipedia 2008 )
CIA Workbook
Wikipedia
Lichtenstein  Europe's fourth smallest state with an area of approximately 100 square miles. The total population is 28,000 of which 18,000 are citizens of the Principality.

I really wish the world (read that as the US) would just stop fooling around and adopt the metric system and dump imperial measures. It would be so much easier not to mention accurate.

RPMiller  I completely agree. Seems the US finds learning from the rest of the world a sign of weakness or failure.
btw. You posted  you owe the thread one interesting measurement :)
please.. (makes pathetic face)

From ocean to ocean (ie. San Diego, CA, USA to St. Simons Island, GA, USA), the shortest travel distance I found is 2,316.5.

I'll post my interesting measurement as a puzzle:
If you have a rope long enough to wrap around the equator of Mars, how much longer must the rope be to allow a 6 Foot tall man to walk underneath it all the way around?

r = radius of Mars in feet
C1 = circumference of Mars in feet
C2 = new length of rope in feet
pi = 3.14159
L = additional length of rope necessary.
C1 = 2 * pi * r
C2 = 2 * pi * ( r + 6 )
C2  C1 = L
Equatorial radius of Mars = 3396.2 km = 11142388 feet
C1 = 70009629 feet
C2 = 70009667 feet
L = 38 feet.
That doesn't seem long enough. Maybe I'll recheck my math...
edit: No, I'm right. C + x = ( 2 * pi * r ) + ( 2 * pi * ( r + x ) ) That's kind of strange; you'd think it would be much bigger.