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Welcome to the Geohashing Community Wiki. Geohashing is a Spontaneous Adventure Generator, brought to you by the xkcd webcomic.
What is this?
xkcd comic #426, published on 21 May 2008, contains an algorithm that generates random coordinates around the world every day. Everyone in a given region gets the same set of coordinates. As such, these coordinates can be used as destinations for adventures, à la Geocaching, or for local meetups.
For a little more interactive discussion, consider joining the #geohashing IRC channel on Foonetic.
Contents
How it works
Play with the coordinate calculator at http://xkcd.com/geohashing. All coordinates refer to the WGS84 datum.
iPhone users can download the app from the iTunes store. (needs iTunes/iPhone)
Every day, the algorithm generates a new set of coordinates for each 1°×1° latitude/longitude zone (known as a graticule) in the world. They are randomly placed -- they could be in the forest, in a city, on a mountain, or even in the middle of a lake! You can use this wiki to document the daily coordinates (geohashes) you’ve been to.
Unless you can accurately predict the stock market down to the penny, you can't figure out what the coordinates will be ahead of time. You can first calculate a weekday’s coordinates at about 9:30am ET, and on Friday you can calculate the coordinates for each day that weekend.
When visiting geohash locations, please respect the area you are visiting. Absolutely do not litter or otherwise disturb the natural integrity of the area. However, if possible, creating some kind of a marker out of nearby materials (i.e. cairn of stones, blair-witch-style ‘stick figures’, etc.) is encouraged.
After the fun, why not document your Expedition? The rest of us would love to read your story, see your photos, and cheer your success (or commiserate with your failure).
Official xkcd meetups
Based on the title text from the comic that established geohashing, the "official" meetup day was interpreted as being Saturday; that is, the day one would have the best chance of meeting others -- see also Mouseover Day. Additionally it was decided through convention that a good meeting time would be 16:00 local time (4:00 P.M.)¹
However, neither of these are hard rules, and they were formulated at a very different early stage in the sport's history. Nowadays and for quite awhile actually, any date or time can be good (or bad, depending on how many other hashers are near you) for meeting up, especially if prearranged. Note that this only applies to that day’s normal local geohash or globalhash coordinates, if you try to go to an alternate location without telling anyone else, it's highly unlikely you'd meet up with a hasher there (obviously).
¹Or earlier if that would be too close to sunset during the winter, or other quirks of temporal tradition; see your local graticule page for consensus there.
Really Cool Expeditions
Sometimes to know how seriously cool a geohashing expedition was, a picture is insufficient. You may need a thousand words. Please contribute links to the Hall of Amazingness of “you have got to see this!” way cool expeditions that we might otherwise not hear about.
| “ | Then I realised, despite all my whining, my pain and exhaustion, my total lack of any positive thoughts at all, I was enjoying myself. I was having one of the most exhilarating times of my life. I was exploring a place that no one had ever been, seeing things no one had ever seen, pushing my body to its limit for a ridiculously pointless goal and loving every second of it.
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” |
| “ | There's probably only one IRC channel in the world where you can complain about the stupid forest not being cold enough at -9°C and everyone understands and agrees without raising an eyebrow.
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” |
Achievements
Sometimes you need to go above and beyond (or, perhaps, beneath and short of) the call of the GPS receiver to get to your hash. The Achievements page lists recognized wins (and fails) of geohashing and corresponding awards.
Active Graticules
Want to find geohashers in your local area? See Category:Active Graticules for a list of graticules with active users in them.
- Don't see your home area? Follow the format and create a page for it! We'd love to have you!
- An interactive map is available for Google Earth or on Google Maps.
Implementations
A full list of reference and practical implementations can be found on the Implementations page.
Recent and Upcoming Coordinates
The coordinates for the next Saturday meetups, scheduled for 7 December 2024, will be based on the Dow’s opening price published at 09:30 EST (14:30 UTC) on Friday 6 December. See timeanddate.com to convert this time to your local time zone.
- Coordinates: Tue 3 Dec* | Mon 2 Dec | Sun 1 Dec | Sat 30 Nov | Fri 29 Nov | Thu 28 Nov | Wed 27 Nov | Tue 26 Nov
* Only known for regions east of 30W longitude. Coordinates for regions to the west announced 14:30 UTC, 3 December. - View expedition archives for: December 2024 | November 2024 | October 2024 | More...
- Refresh the cache
Gallery of Recent Expeditions
The gallery for each day is added to this page automatically, but pictures are selected to the gallery by us. Any geohasher is welcome to add a picture from that day. Just add your image name in the list at the “add yours” link. If the gallery hasn't been started yet, copy the format from the previous day, or read the how-to.
Known Issues
Several known issues are presented at Known Issues. There is an ongoing discussion on these and other issues at Talk:Main Page.
FAQ
Q: What should I bring?
- A: See What to bring.
Q: I don't have a car, how am I supposed to participate in this sport?
- A: Some of the most avid geohashers don't use cars. Geohashing is suitable for bicycles or by public transit.
Q: Is it okay to visit a geohash location in a neighbouring graticule instead of my “own” one?
- A: Sure! There’s no rule saying you can't visit other graticules, and in some cases (for example, San Francisco), you would almost have to in order to actually access a hashpoint. Geohashing is about meeting other people, and it doesn't matter whether you do that here or there. In fact, finding a new mix of people might be a good thing. Go ahead and geohash on vacation for all we care!
Q: What do I do when I get there?
- A: Poke around, take pictures, have a picnic, and, in general, have fun! The world is an adventure!
Q: What do I say to puzzled locals?
- A: See Cover Stories.
Q: How will Geohashing get me laid?
- A: You never know who you might find when you show up next Saturday.
Q: Is there a Facebook group for my area?
- A: Take a look at the Facebook groups page.
Q: What if I can't access the exact location, but still think others nearby are trying to meet up?
- A: See Radio Communications.
Q: I tried to use the md5sum from my unix/linux command line and the hash was not the same as the comic. What is the correct command line?
- A: You probably forgot the “-n” (echo without a newline). Try this to match the example:
echo -n 2005-05-26-10458.68 | md5sum- The md5sum command may be called md5 instead.
