(urth) The Apu-Punchau Eclipse

[Dan'l Danehy-Oakes]

On Tue, Jun 10, 2008 at 6:07 PM, Jeff Wilson <jwilson at io.com> wrote:
> Dan'l Danehy-Oakes wrote:
>>
>> Tzadkiel's Ship -- *counting its sails*, is significantly bigger than a
>> mile
>> in diameter, at least for purposes of shadow-casting. Solar sails have
>> to be (a) very very large and (b) quite opaque in order to be effective.
>
> LEO velocity is about 5 miles per second, so each second of eclipse is 5
> miles worth of ship, plus the penumbra penalty (altitude times twice the
> tangent of the sun's arc width (0.5 degrees)). There would also need to be
> some means of maneuvering the entire ship within a moment or a massive
> number of crew available to trim the sails in a like period of time.

The numbers I've seen for an effective solar sail are in the range of
tens of thousands of miles.


-- 
Dan'l Danehy-Oakes, writer, trainer, bon vivant
-----
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