Can’t we just use the metric or imperial system? why is there a need to use this measurement that is seemingly coming from chopping the earth into half and dividing its circumference by 360 degrees, and then calculating a minute of arc of it?
Also what did I just say? The way this measurement is made makes no sense
In: 0
You take the circumference of the planet and divide it into 360°, which makes sense because the circumference is a circle and we usually divided circles into 360 degrees. Since the world is big a single degree is quite a lot of distance so we further subdivide a degree into 60 minutes and those minute into 60 seconds. (This is not a thing specific to geography but a general thing we do with degrees of an arc in geometry.)
A degree of longitude on the equator is more or less the same distance as a degree of latitude anywhere. (Not quite because the earth is not a perfect sphere but more of squashed potato.)
Nautical miles are easy to use with a coordinate system because 40° 43′ N, 74° 0′ W is exactly one nautical mile south of 40° 44′ N, 74° 0′ W.
The 43′ and 44′ are the minutes of an arc.
It doesn’t work as well for longitude as latitude because the earth is round by at least on the equator a minute west or east is a nautical mile.
Kilometer is sort of based on the same general idea, but instead of chopping up the distance from equator to pole into 90 degree with 60 minutes each we chop up the distance into 10,000 kilometer with 1000 meter each.
Nautical miles is an older system and has kept on because everyone was using it in boats and later planes for distance and speed (knots are nautical miles per hour).
It would make more sense to use kilometers and km/h everywhere, but people are used to nautical miles and knots and with computers it is easy to display numbers in any unit you want.
Can’t we just use the metric or imperial system? why is there a need to use this measurement that is seemingly coming from chopping the earth into half and dividing its circumference by 360 degrees, and then calculating a minute of arc of it?
Also what did I just say? The way this measurement is made makes no sense
In: 0
You take the circumference of the planet and divide it into 360°, which makes sense because the circumference is a circle and we usually divided circles into 360 degrees. Since the world is big a single degree is quite a lot of distance so we further subdivide a degree into 60 minutes and those minute into 60 seconds. (This is not a thing specific to geography but a general thing we do with degrees of an arc in geometry.)
A degree of longitude on the equator is more or less the same distance as a degree of latitude anywhere. (Not quite because the earth is not a perfect sphere but more of squashed potato.)
Nautical miles are easy to use with a coordinate system because 40° 43′ N, 74° 0′ W is exactly one nautical mile south of 40° 44′ N, 74° 0′ W.
The 43′ and 44′ are the minutes of an arc.
It doesn’t work as well for longitude as latitude because the earth is round by at least on the equator a minute west or east is a nautical mile.
Kilometer is sort of based on the same general idea, but instead of chopping up the distance from equator to pole into 90 degree with 60 minutes each we chop up the distance into 10,000 kilometer with 1000 meter each.
Nautical miles is an older system and has kept on because everyone was using it in boats and later planes for distance and speed (knots are nautical miles per hour).
It would make more sense to use kilometers and km/h everywhere, but people are used to nautical miles and knots and with computers it is easy to display numbers in any unit you want.
Latest Answers