Difference between revisions of "Time-traveller achievement"
From Geohashing
imported>Mckaysalisbury (Ahh, I see what you mean now. Let me clarify and clean up.) |
imported>Benjw (more tidying up) |
||
| Line 13: | Line 13: | ||
** Geohashers near longitude 0° or 180° might be lucky and not have to travel far at all. | ** Geohashers near longitude 0° or 180° might be lucky and not have to travel far at all. | ||
* Be in a mirror graticule and get extremely lucky. | * Be in a mirror graticule and get extremely lucky. | ||
| − | ** Because graticules that touch across the equator or the prime meridian or the 180° meridian mirror each other, there is a very small chance, if you're standing on the border between them, you could be in the circle of uncertainty for two hashpoints simultaneously. | + | ** Because graticules that touch across the equator or the prime meridian or the 180° meridian mirror each other, there is a very small chance, if you're standing on the border between them, that you could be in the circle of uncertainty for two hashpoints simultaneously. |
*** For those graticules that touch across the equator, this happens if the latitude of the hashpoint is less than 0.000036°. | *** For those graticules that touch across the equator, this happens if the latitude of the hashpoint is less than 0.000036°. | ||
| − | *** For those that touch across the prime or 180° meridian, the longitude of hashpoint | + | *** For those that touch across the prime or 180° meridian, the required longitude of the hashpoint can be calculated from the expression 0.000036° / cos(latitude). |
| − | *** Note that across the 180° Meridian, they points only mirror each other on the weekend, because of the | + | *** Note that across the 180° Meridian, they points only mirror each other on the weekend, because of the [[30W Time Zone Rule|30°W rule]]. |
| − | * Go near the poles and be lucky | + | * Go near the poles and be lucky. |
| − | ** | + | ** At latitudes 89°N or 89°S, because graticules get narrower east-west the further north they are, hashpoints at all longitudes are closer to each other. When the latitude of the hashpoint is greater than 89.9984° the circles of uncertainty for two hashpoints will overlap. |
| − | * Get very very extremely lucky because of the | + | * Get very very extremely lucky because of the 30°W rule. |
** On weekdays hashpoints east and west of longitude 30°W are calculated separately, so may both be close to 30°W or 180°E/W. However, pretty much all of these points will be in an ocean. | ** On weekdays hashpoints east and west of longitude 30°W are calculated separately, so may both be close to 30°W or 180°E/W. However, pretty much all of these points will be in an ocean. | ||
Revision as of 07:37, 26 April 2016
|
This user earned the Time-traveller achievement
|
The achievement can be claimed if you venture to two or more geohashing locations on the same day and the same local time.
If you don't own a time-machine, you could ...
- cross a time-zone border.
- take advantage of the autumn daylight saving clocks change.
- Geohashers nearer the equator are at a disadvantage because they have further to travel east or west.
- Geohashers near longitude 0° or 180° might be lucky and not have to travel far at all.
- Be in a mirror graticule and get extremely lucky.
- Because graticules that touch across the equator or the prime meridian or the 180° meridian mirror each other, there is a very small chance, if you're standing on the border between them, that you could be in the circle of uncertainty for two hashpoints simultaneously.
- For those graticules that touch across the equator, this happens if the latitude of the hashpoint is less than 0.000036°.
- For those that touch across the prime or 180° meridian, the required longitude of the hashpoint can be calculated from the expression 0.000036° / cos(latitude).
- Note that across the 180° Meridian, they points only mirror each other on the weekend, because of the 30°W rule.
- Because graticules that touch across the equator or the prime meridian or the 180° meridian mirror each other, there is a very small chance, if you're standing on the border between them, that you could be in the circle of uncertainty for two hashpoints simultaneously.
- Go near the poles and be lucky.
- At latitudes 89°N or 89°S, because graticules get narrower east-west the further north they are, hashpoints at all longitudes are closer to each other. When the latitude of the hashpoint is greater than 89.9984° the circles of uncertainty for two hashpoints will overlap.
- Get very very extremely lucky because of the 30°W rule.
- On weekdays hashpoints east and west of longitude 30°W are calculated separately, so may both be close to 30°W or 180°E/W. However, pretty much all of these points will be in an ocean.
Of course, as usual, you need to upload photos of yourself containing the necessary proof.
Winners
- Woodveil was at the 2009-03-08 33 -84 and 2009-03-08 33 -85 hashes at 12:39 local time.
- B2c and Patrizius were at the 2013-10-27 47 13 and 2013-10-27 47 12 hashes at 02:09 local time. It was a DST time travel.
- Micsnare and B2c were at the 2014-10-26 47 14 and 2014-10-26 47 13 hashes at 02:01 local time. It was a DST time travel. Again ;)
See also
Multihash -- reach multiple geohashes on one day
