Exact opposite of a lat / long position?

December 21, 2004 5:38 PM

If I know the latitude and longitude of where I live, how would I find out the name of the place exactly opposite it on the globe?
posted by reklaw to Science & Nature (14 answers total)

Couldn't you simply add 180 degrees to either lat or long and consult a map? Just remember to turn it over when you go past 360.
posted by aladfar at 5:46 PM on December 21, 2004

Do a search on metafilter for the word "antipode" and - viola! - you come up with this.
posted by googly at 5:48 PM on December 21, 2004

Alas, I used to have a widget but then Xerox restricted their maps. I use this map when I'm dying to know, nowadays.
posted by jessamyn at 6:03 PM on December 21, 2004

Wasn't this just discussed in the Blue?
posted by Octaviuz at 6:05 PM on December 21, 2004

Make a hole with a gun perpendicular to the name of your town on a desktop globe?
posted by mr_roboto at 6:06 PM on December 21, 2004

Response by poster: Ah, that page with the overlaid maps is great, thanks!

Unfortunately the answer for me (in London) is ocean, but I guess I should have known that. I was kinda hoping for a nice place in Australia...
posted by reklaw at 6:45 PM on December 21, 2004

Given your latitude and longitude, to find the coordinates of the opposite point:
For the latitude, simply change N to S or vice versa; and,
For the longitude, subtract from 180° and change E to W or vice versa (keep in mind when doing this calculation that a minute is 1/60th of a degree, and a second is 1/60th of a minute, and calculate accordingly.)

E.g., the point opposite 40° 21' N 86° 33' W is 40° 21' S 93° 27' E.

If you're using a system which uses signed longitude and latitude (north and east are positive, by convention; south and west are negative), then: take the negative of the latitude; and add 180° to a negative longitude, or subtract 180° from a positive longitude (again remembering minutes and seconds).

Once you have the coordinates of the opposite point, you can map it using Mapquest's Map by lat/long page. (If you're in the middle of an ocean, as most U.S. residents will be, you may need to zoom out to the widest view to see where you are.)
posted by DevilsAdvocate at 6:50 PM on December 21, 2004

Exit wound in a foreign nation, showing the home of the one this was written for.

You sunk my battleship, mr_roboto. Very nice.
posted by Alt F4 at 7:10 PM on December 21, 2004

Sounds like someone is planning on digging a very, very big hole...
posted by Robot Johnny at 8:16 PM on December 21, 2004

mr_roboto, will you marry me?
posted by Plutor at 7:47 AM on December 22, 2004

Uh, that antipode thing doesn't work for me. I've tried putting in my city (Panama City), it doesn't have results. I tried pensacola and tallahassee. Still no results. Fine, I said, HOW ABOUT ORLANDO?

Still no results.

Is Florida a gigantic void?
posted by u.n. owen at 9:56 AM on December 22, 2004

Also, Plutor, be careful about asking people on the internet to marry you in the middle of a discussion, just because they said the coolest thing ever. One time I did that during a fark flamewar and now it appears it'll actually be happening.
posted by u.n. owen at 9:58 AM on December 22, 2004

I don't want the world. I just want your half.
posted by norm at 11:46 AM on December 22, 2004

Is Florida a gigantic void?

That's one of them rhetorical questions, right?
posted by terrapin at 11:59 AM on December 22, 2004