10-03-2005, 06:10 PM #1
Longitude; Latitude; and Proper time zones
Anyone know where I can find them>?
10-03-2005, 07:53 PM #2
10-03-2005, 07:54 PM #3
try a map dumbass..hahaha
10-04-2005, 12:42 AM #4Originally Posted by needmorestrength
The reference for time on our planet is 0 degrees longitude, also known as the Greenwich Meridian, so called because the Royal Observatory in Greenwich, England, is where much of our early navigational science was developed. Longitude goes through 180 degrees west and 180 degrees east of Greenwich. Add it up, Sweetie... 360 degrees, total. Now, there are 24 hours in a day, right? if you divide 360 by 24, you get 15, so time zones are theoretically 15 degrees of longitude wide. GMT, or Greenwich Mean Time, is observed at the Greenwich Meridian, and 7 degrees thirty minutes to the east and to the west of the meridian, which is the nominal meridian for that time zone. Going west, zones are labeled plus 1, plus 2, plus 4, etc all the way to plus 12. Adding the zone description to the zone time gives you GMT, Greenwich Meridian Time, or Zulu time. Going East from Greenwich, the zones are labeled minus 1, minus 2, etc, all the way to minus 12. So 24 time zones, right? Actually, wrong. There are actually 25 time zones... don't forget about GMT., zone description zero. The international date line seperates the plus 12 from the minus 12 zones, and those two zones are only 7.5 degrees wide. What is the difference between the time 12 hours earlier than GMT and 12 hours later than gmt? 24 hours, one whole day, thus the international date line. As you go east, you gain hours until you cross the date line, when you lose a day, and vice versa traveling west.
In practice, the time zone boundaries do not necessarily hold precisely to the 15 degrees of longitude centered on the nominal meridian of the zone. This is a matter of arbitrary convenience, so you can have a state, province, or country that does not straddle two time zones, or sometimes a zone boundary follows a geographic feature such as a river, or mountain range. The international date line takes a couple of zig zags, too, to keep from confusing people about what day it is from, say, one village in Siberia versus the village a mile down the road, or the next little island or atoll in the mid pacific. There are even localities that keep time a half hour away from the next zone. Time reference is a purely arbitrary concept, and so we can basically do what the hell we want with it. We even had an idiot in this country who was SUPPOSED to be a pretty smart guy, who invented something really screwed up... Daylight Savings Time. I say, if you want to get up an hour earlier, just get up earlier... don't try to make ME set MY watch back or forward according to a completely unnecessary and unproductive whim! This genius? A hint... he sat through a high level government meeting staring at the back of a chair, and finally, after several hours, exclaims that the design represents a RISING, and not a SETTING sun. What a lamer! Then, our genius goes out and performs an experiment with a kite in a thunderstorm to prove that lightning is electricity. Duh. THAT's the moron who invented daylight savings time.
If you have a shortwave radio receiver, try tuning to 5, 10, 15, or 20 megacycles (Sorry... megahertz to you young pups) and catch the WWV or WWVH time signal broadcasts. These "time ticks" are referenced to an atomic clock kept by the national institute of standerds or something like that, and is the final word in what time it is.
Longitude can be roughly determined by noting your position on a map or a globe, and interpolating between the marked meridians. Latitude likewise. Longitude is a measurement of how far east or west you are, and so longitude lines, meridians, run north/south. Latitude goes from zero at the equator to 90 degrees north (the north pole) or 90 degrees south... (guess where that is) and so latitude lines run east/west. With both coordinates, you can locate your position on the planet.
You can buy a GPS reciever that fits in your shirt pocket for around $100 at walmart or most larger sporting goods stores. Amaze your friends by giving them your latitude and longtitude, instead of your address!
Homework... read a book on spherical trigonometry, and figure out how to calculate the distance between two points on the globe. HINT... just presuming a flat surface and using straight plane trigonometry does not work except for fairly short distances. MORE HOMEWORK... invent a metric system of time and longitude measurement and implement your system into a system of navigation. Both projects due at the beginning of class tomorrow. MORE HOMEWORK... explain why, while a plane triangle must always have angles that total 180 degrees, a sperical triangle will always have three angles that total more than 180 degrees. EVEN MORE HOMEWORK... explain the significance of the Arctic and Antarctic circles and the tropics of Cancer and Capricorn relative to the plane of the exliptic.
Oh, Darling, Isn't Google just Absolutely Fabulous?
Professor Anna, Queen of Googling
10-04-2005, 04:13 AM #5Originally Posted by Decadbal
10-04-2005, 04:15 AM #6
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)