2006-09-06 11:55:13 · 9 answers · asked by gerbil_girl_11 2 in Science & Mathematics ➔ Geography
Lines (or meridians) are measured all the way around the earth. There are 360 degrees around the earth, therefore there are 360 main meridians. However, degrees can be sub divided into 60 minutes and 60 seconds. I'll leave the math to you.
2006-09-06 12:20:08 · answer #1 · answered by atwil 5 · 0⤊ 0⤋
There are really as many "lines of longitude" as there are points on a circle. That's infinitely many.
If you only want to count whole degrees, then there are 360. If you add in minutes and seconds, then each degree can be subdivided into 60 minutes, which can be subdivided into 60 seconds. So there are 360*60*60 = 1296000 lines of longitude corresponding to precise "seconds".
There's nothing in principle that would stop you from subdividing these into half-seconds, quarter-seconds, eighth-seconds and so forth, but since the distance between "seconds" lines is only about 30 meters at most (at the equator), there usually isn't a practical need to do so :-)
2006-09-06 18:19:52 · answer #2 · answered by Bramblyspam 7 · 0⤊ 0⤋
Actually, there is an infinite number of longitudinal lines that can be described. You can define 000º00'00" and 001º00'00". You can then describe a longitude halfway between those two (000º30'00"), another between that one and the first one (000º15'00"), and so on, indefinitely. An example of an infinite number of points in a finite, measureable space.
Works the same way with linear measurement. Consider two lines one inch apart, then 1/2 inch, then 1/4 inch, then 1/8 inch, etc.
If you're talking about whole degrees, 360. Minutes, 21,600. Seconds, 1,296,000.
2006-09-06 12:57:01 · answer #3 · answered by Adashi 3 · 1⤊ 0⤋
There is only one. The prime meridian.
Some people consider the international date line to be another, but it is not truly a line of longitude. It isn't straight.
2006-09-06 13:39:05 · answer #4 · answered by Anonymous · 0⤊ 0⤋
As far as I KNow, there are not a set number of lines. The lines of Longitude measure degrees, and then they are broken down further into hours and minutes. You may want to read up.
2006-09-06 11:59:56 · answer #5 · answered by weebat 3 · 0⤊ 1⤋
the lines of longitude go up to 180 so 358 total is my guess if you're talking about one degree at a time
2006-09-06 12:07:51 · answer #6 · answered by Anonymous · 0⤊ 1⤋
180
2006-09-06 22:37:15 · answer #7 · answered by CARLOS_TINCO 2 · 0⤊ 0⤋
Adashi nailed it. An infinite number.
2006-09-06 17:33:13 · answer #8 · answered by PI Joe 5 · 0⤊ 0⤋
the prime MERIDIAN and Greenwich Meridian
2006-09-09 00:40:59 · answer #9 · answered by free aung san su kyi forthwith 2 · 0⤊ 0⤋