# 12203 byhitssquad@... on Jan. 30, 2012, 8:38 a.m.
Member since 2021-10-03
--- In spacesettlers@yahoogroups.com, Al Globus wrote:
> http://alglobus.net/NASAwork/papers/PathsToSpaceSettlement2011.pdf
Isn't it one part in 2.21 billion (3.846e26 watts / 1.74e17 watts; and that's just what Earth intercepts, much of which is reflected)?
# 12204 byalglobus@... on Jan. 31, 2012, 2:32 a.m.
Member since 2021-10-03
On Jan 30, 2012, at 12:38 AM, hitssquad wrote:
> --- In spacesettlers@yahoogroups.com, Al Globus wrote:
> > http://alglobus.net/NASAwork/papers/PathsToSpaceSettlement2011.pdf
>
> That paper says: "Only one part in 625 million of the Sun's energy
> falls on Earth, the rest is radiated away into space."
>
> Isn't it one part in 2.21 billion (3.846e26 watts / 1.74e17 watts;
> and that's just what Earth intercepts, much of which is reflected)?
>
I've done the calc several times and get about the same number. It
depends a little on which solar-Earth distance you choose. I might
have made a mistake too.