[TML] Alderson disk

[shadow at shadowgard.com]

Okay, I wrote the program. Here's the output...

 time  altitude      angle
 ----  ------------  --------
 0     1.492992E+11  45 
 1     1.492344E+11  44.98756 
 2     1.4904E+11    44.95022 
 3     1.48716E+11   44.88787 
 4     1.482624E+11  44.80036 
 5     1.476792E+11  44.68745 
 6     1.469664E+11  44.54886 
 7     1.46124E+11   44.38421 
 8     1.45152E+11   44.19307 
 9     1.440504E+11  43.97494 
 10    1.428192E+11  43.72923 
 11    1.414584E+11  43.45529 
 12    1.39968E+11   43.15239 
 13    1.38348E+11   42.81971 
 14    1.365984E+11  42.45634 
 15    1.347192E+11  42.06132 
 16    1.327104E+11  41.63354 
 17    1.30572E+11   41.17184 
 18    1.28304E+11   40.67494 
 19    1.259064E+11  40.14147 
 20    1.233792E+11  39.56995 
 21    1.207224E+11  38.95879 
 22    1.17936E+11   38.30628 
 23    1.1502E+11    37.61063 
 24    1.119744E+11  36.8699 
 25    1.087992E+11  36.08204 
 26    1.054944E+11  35.24492 
 27    1.0206E+11    34.35627 
 28    9.8496E+10    33.41372 
 29    9.48024E+10   32.41484 
 30    9.097921E+10  31.35709 
 31    8.70264E+10   30.23788 
 32    8.2944E+10    29.0546 
 33    7.8732E+10    27.80464 
 34    7.43904E+10   26.48542 
 35    6.99192E+10   25.09444 
 36    6.53184E+10   23.62938 
 37    6.0588E+10    22.0881 
 38    5.5728E+10    20.46879 
 39    5.07384E+10   18.77001 
 40    4.56192E+10   16.99082 
 41    4.03704E+10   15.13089 
 42    3.4992E+10    13.19061 
 43    2.9484E+10    11.17118 
 44    2.38464E+10   9.074759 
 45    1.80792E+10   6.904544 
 46    1.21824E+10   4.66484 
 47    6.155993E+9   2.361116 
 48    0             0 
 
That is some *very* non-standard movement. It takes 8 hours to move 
the first degree from sunhigh. But it's moving over 2 degrees an hour 
by sunset.

Compare this with earth where 15 degrees an hour is normal.

Here's the quick & dirty Basic program I used to generate the data 
(yes, I tweaked it to make the sunhigh to sunset period exactly 48 
hours)

r=.5*10*(48*3600)^2
pi=4*atn(1)
open "sunfall.txt" for output as 1
for t=0 to 49
 d=.5*10*(t*3600)^2
 h=r-d
 tn=h/r
 a=atn(tn)*360/(2*pi)
 print t, h, a
 print #1, t, h, a
next t

I'd love it if somebody with greater skills than I would do up a 
short animation of the sunhigh to sunset sequence (obviously speed up 
:-)


--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com