Re: A newcomer here

"David Friedman" <ddfr@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:ddfr-DAA931.18240812092005@xxxxxxxxxxxxxxxxxxxxxxxx
> In article <GepVe.3508$XO6.2586@trnddc03>,
> "Logan Kearsley" <chrono.surfer@xxxxxxxxxxx> wrote:
>
> > With constant crust thickness and density, the surface gravity
> > increases as the radius increases.
>
> No. It stays constant.
>
> Area goes as the square of radius, so with constant thickness and
> density mass goes as the square of radius.

Except that it doesn't, exactly. It's somewhat off. Assuming constant
density, the mass is dependent on the volume of the shell, which is the
volume of the spherical world minus the volume of the empty spherical
interior. This will only scale with the surface area / square of the radius
if the ratio between the outer sphere and the inner sphere is constant, but
if the shell thickness is constant, that ratio won't be.

> Surface gravity goes as mass
> over radius squared.

-l.
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Relevant Pages

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  • Re: A newcomer here
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  • Re: A newcomer here
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  • Re: A newcomer here
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    (rec.arts.sf.composition)