## Forum

 Wednesday, May 21, 200810 years ago • 2,702 views xkcd.com/geohashing Anyone understood the theory??? 10 years ago # As far as I understood, you take 3 input variables, date, the DOW () opening, and location coordinates.Then you get the date and dow's number hashes using md5 (en.wikipedia.org/wiki/MD5). You get two alpha-numeric strings. Each string is then taken to a (numeric) decimal system. Let's call this two numbers D1 and D2.Now we take the location coordinates. We truncate them to get rid of decimal numbers. This two numbers will be, say, X and Y.Finally, the output of the process are two numbers (coordinates), X+D1, and Y+D2. This coordinates are quite random. So given coordinates, and a date, depending on the DOW opening of the day you calculate it, you get new coordinates.Blag entry at XKCD: blag.xkcd.com/2008/05/21/geoha ... 10 years ago # wiki.xkcd.com/geohashing/Main_ ... It may help. 10 years ago # I mean I got the formula, but not the use?Not even in the comic sense :( 10 years ago # I end up in the middle of the sea.... Hmm maybe doing this on the South coast of England isn't such a good idea :-) 10 years ago # Well, I took it to mean you go Geocaching but you pick the destination by Geohashing. Instead of looking for somewhere people have already been, you just run the formula from the comic and it gives you a destination to go. 10 years ago # Here's a description from their wiki:<> wiki.xkcd.com/geohashing/Main_ ... 10 years ago # A mostly natural progression from the earlier comic: xkcd.com/240/ That resulted in a gathering out in North Cambridge, MA. This thread is locked as it's old... but you can create a new thread in the forum.

Forum home