Ronn! Blankenship wrote: > >> Using a Hohmann transfer orbit to go from >> 100 AU to 2 AU would require such a long time that when the >> ship arrived, it would be populated by the grandchildren of the >> original crew. > > The applicable formula in this case is Newton's version of Kepler's Third Law: > > P^2 = (M+m)*a^3, > > (...) > > If the planet at 2AU is supposed to get the same total amount of > radiation as Earth, that would imply a hotter, brighter, more > massive star, whose greater gravity would cut the time down to > about 125 years. > This is the period of the ellptic orbit. The travel would take half of this, or 60 years, or two generations. QED :-)
Alberto Monteiro _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
