= Stady Materials =
== Materials in solar system for Stapledon-Dyson Static-Dynamic 50 AU Shell, 60K ==
--------

=== Source Planets and Moons ===

||<-2>                      ||<:-3> Velocity km/s        ||
||<:>  Object    || Mass kg || Orbit || Escape || Center || Temp K || Composition                   ||
||''' Mercury '''|| 3.30e23 ||  47.4 ||   4.25 ||   47.7 || 85-700 || iron core, silicate mantle    ||
||'''   Venus '''|| 4.87e24 ||  35.0 ||   10.4 ||   37.3 ||    737 || ?                             ||
||<)>  Asteroids || 3.xxe19 || 16-20 || < 0.51 ||  16-20 || 85-270 || some iron, silicates          ||
||''' Jupiter '''|| 1.90e27 ||  13.1 ||   59.5 ||   74.0 || 112+   || H, He, some core rock         ||
||<)>   Callisto || 1.08e23 ||   8.2 ||    2.0 ||   15.6 || 80-165 || H₂O and rock                  ||
||'''  Saturn '''|| 5.68e26 ||   9.7 ||   35.5 ||   44.5 || 84-134 || H, He, some core rock         ||
||<)>      Titan || 1.34e23 ||   5.6 ||    2.6 ||   11.6 ||     94 || H₂O and rock                  ||
||'''  Uranus '''|| 8.68e25 ||   6.8 ||   21.3 ||   27.0 ||  47-76 || H, He, 2.3% methane           ||
||<)>    Titania || 3.53e21 ||   3.6 ||    0.8 ||    7.8 ||  60-89 || H₂O, organics, rock           ||
||''' Neptune '''|| 1.02e26 ||   5.4 ||   23.5 ||   29.3 ||  55-72 || H, He, trace methane          ||
||<)>     Triton || 2.14e22 ||   4.4 ||    1.5 ||    7.2 ||     38 || H₂O and rock                  ||

The energy to escape from the center of the planet is 1.5 times the surface escape velocity, assuming (optimistically) uniform density. "Center" is the escape velocity from the center of the planet to solar escape.  

Although the usual Dyson Sphere literature dotes on taking apart planets - particularly Earth for some reason, perhaps sociopathic authors - big planets are difficult to use, especially if the good stuff is deep inside, and not beneficiated by plate tectonics and ocean/biological chemistry.  Asteroids are prefractured planetesimals, and many are threats to the Earth and ought to be removed.  Uranus is better than Neptune as a source of carbon, more carbon (in methane), easier to get to, 60% more solar energy.

=== Abundance ===

|| Element || ppm by weight ||
||  Oxygen ||        10,000 ||
||  Carbon ||         4,600 ||
||    Iron ||         1,000 ||
|| Silicon ||           650 ||

=== Resistivity ===

 . https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity
 . http://www.bnl.gov/magnets/Staff/Gupta/cryogenic-data-handbook/Section10.pdf


||  Element ||<-5> e-8 Ω-m, imprecise estimates           || Graph ||
||          ||   300 K || TC /K || ≃ 80 K || 73 K || 53 K ||  60 K ||
||   Silver ||     1.6 ||       ||   0.33 || 0.28 || 0.15 ||  0.19 ||
||   Copper ||     1.7 || 0.004 ||        ||      ||      ||  0.11 ||
|| Aluminum ||     2.8 || 0.004 ||   0.28 || 0.33 || 0.20 ||  0.22 ||
||     Iron ||    10.0 || 0.005 ||   0.74 || 0.62 || 0.27 ||  0.35 ||