Talk:2018-01-31 43 19

From Geohashing

I do believe you are entitled to the Juggernaut Achievement,Air Geohash and if you were skillful enough and went to the bathroom in time, also the Geoflashing ;) --ChromeCrusaders (talk) 22:39, 3 February 2018 (UTC)

Well spotted! I'll add juggernaut to the list along with "air" and "mile high". This makes flying less boring but no more comfortable. Explaining the squeeks of excitement as the distance falls followed by the satisfied "Yes" when it drops below 310 metres is more of a problem! --Sourcerer (talk) 06:45, 5 February 2018 (UTC)

Probabilities

0.5% × 50 = 25%, yes, but... that's not how probabilities work! If it was, then you could say that flying across 200 graticules gave you a 0.5 × 200 = 100% chance of success, which is clearly false!

The correct formula for estimating the probability that a flight will pass within the circle of uncertainty of hashpoint, all other things being equal (i.e. ignoring characteristics of air traffic or of the size of graticules), assuming the chance of success in one graticule is 0.5%, is: 1 - 0.995n, where n is the number of graticules crossed. This gives us the following results:

Graticules crossed Chance of hitting hashpoint (assuming 0.5% chance per graticule)
1 0.500%
2 0.997%
3 1.493%
4 1.985%
5 2.475%
6 2.963%
7 3.448%
8 3.931%
9 4.411%
10 4.889%
11 5.365%
12 5.838%
13 6.309%
14 6.777%
15 7.243%
16 7.707%
17 8.168%
18 8.628%
19 9.084%
20 9.539%
21 9.991%
22 10.441%
23 10.889%
24 11.335%
25 11.778%
26 12.219%
27 12.658%
28 13.095%
29 13.529%
30 13.962%
31 14.392%
32 14.820%
33 15.246%
34 15.669%
35 16.091%
36 16.511%
37 16.928%
38 17.343%
39 17.757%
40 18.168%
41 18.577%
42 18.984%
43 19.389%
44 19.792%
45 20.193%
46 20.592%
47 20.990%
48 21.385%
49 21.778%
50 22.169%
51 22.558%
52 22.945%
53 23.330%
54 23.714%
55 24.095%
56 24.475%
57 24.852%
58 25.228%
59 25.602%
60 25.974%
61 26.344%
62 26.712%
63 27.079%
64 27.443%
65 27.806%
66 28.167%
67 28.526%
68 28.884%
69 29.239%
70 29.593%
71 29.945%
72 30.295%
73 30.644%
74 30.991%
75 31.336%
76 31.679%
77 32.021%
78 32.361%
79 32.699%
80 33.035%
81 33.370%
82 33.703%
83 34.035%
84 34.365%
85 34.693%
86 35.019%
87 35.344%
88 35.667%
89 35.989%
90 36.309%
91 36.628%
92 36.944%
93 37.260%
94 37.573%
95 37.886%
96 38.196%
97 38.505%
98 38.813%
99 39.119%
100 39.423%

--DanQ (talk)