Re: suppose there was an earth sized watermelon?

From: Scott Robinson (dscottr_at_bellatlantic.net)
Date: 11/23/04 

Date: Tue, 23 Nov 2004 21:34:54 GMT

On Mon, 22 Nov 2004 20:04:23 GMT, throopw@sheol.org (Wayne Throop)
wrote:

>: frisbieinstein@yahoo.com (Patrick Powers)
>: Think of it this way: a watermelon crust can easily withstand a force of 1 G.
>
>: So a watermelon the size of the earth with even a one-inch crust would
>: not collapse due to gravity.
>
>You can *think* of it that way.
>In reality, it can't withstand, and it would collapse.
True, but the problem isn't the crust, it's the center. If the
watermelon simply kept growing, the center would be simply compress
until it could support the weight of the crust. If you took a shallow
(1 foot) core sample of a watermelon planet, it would closely
resemble a typical watermelon. Dig a few feet deeper and you start to
get liquified watermelon. At the core of the planet, you might get
weird states of ice, and (according to Wayne) nuclear heating.

Nothing prevents a 1" crust of a naturally grown watermelon planet
(besides boring questions of biological necessity). Of course, they
wind up being like a tree, with the strong dead support in the center,
and the growth at the extremes. You just can't convert a planet into
a watermelon. The planet would collapse into a much smaller ball of
watermelon surrounding a huge ball of water, with a crust that just
doesn't fit all broken up on top.

>
>: Heck, you can take a hen's egg and squeeze the ends as hard as you can
>: and it won't break.

That's the whole point. Stretch an egg out to the size of a planet
and it's essentially flat. Far worse than the sides of the egg.

>
>And you have extensive experience with hen's eggs the size of a planet?
>
>: The center's heat: I'm not sure.
>
>I'm pretty sure. To some extent, depends on initial conditions,
>but a mostly-water sphere starting at uniform room temperature and density
>of about 1 gm/cc the size of earth will heat due to compression;
>there's not too much doubt about that.
>
>
>Wayne Throop throopw@sheol.org http://sheol.org/throopw
This is why I come to r.a.sfwritten. Where else can you discuss the
properties of planetary watermelons?

Scott

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