suppose there was an earth sized watermelon?

(neurocratic malfunction) wrote in message . com...
i know such a thing is not possible of ever existing, but suppose...

with a snap of a finger, planet earth turned into a giant watermelon.

what would happen?

this is my prediction. tell me if you think i'm right.

gravity would immediately collapse the watermelon and the center would
turn very hot due to the sheer pressure of the damn thing.


I doubt it. Realize that the crust would be maybe 200 miles thick.

Think of it this way: a watermelon crust can easily withstand a force
of 1 G. If that 1 G came from its own center, so much the better:
this is the direction from which a sphere is strongest. So a
watermelon the size of the earth with even a one-inch crust would not
collapse due to gravity. Heck, you can take a hen's egg and squeeze
the ends as hard as you can and it won't break.

The center's heat: I'm not sure. Much of the heat in the earth is due
to radioactivity. The ocean doesn't heat up the deeper one goes.

In article ,
says...
(neurocratic malfunction) wrote in message . com...
i know such a thing is not possible of ever existing, but suppose...

with a snap of a finger, planet earth turned into a giant watermelon.

what would happen?

this is my prediction. tell me if you think i'm right.

gravity would immediately collapse the watermelon and the center would
turn very hot due to the sheer pressure of the damn thing.

I doubt it. Realize that the crust would be maybe 200 miles thick.

Think of it this way: a watermelon crust can easily withstand a force
of 1 G. If that 1 G came from its own center, so much the better:
this is the direction from which a sphere is strongest. So a
watermelon the size of the earth with even a one-inch crust would not
collapse due to gravity. Heck, you can take a hen's egg and squeeze
the ends as hard as you can and it won't break.

As somebody pointed out already, on the scale of the Earth, granite is a
fluid. Why do you think the Earth is a sphere in the first place?

- Gerry Quinn

: (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.

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

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 http://sheol.org/throopw

On Mon, 22 Nov 2004 20:04:23 GMT, (Wayne Throop)
wrote:

: (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 http://sheol.org/throopw
This is why I come to r.a.sfwritten. Where else can you discuss the
properties of planetary watermelons?

Scott

Scott Robinson wrote in message . ..

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.

We are confusing two things, impact strength and strength with respect
to uniform force. For resistance to uneven force the flat surface is
weaker. But for resistance to uniform force an infinitely large flat
surface should be strong. The force of gravity is constant and always
perpendicular to the surface, and there is no weakest point. There
is no center to sag and collapse.

Look at a surf board. They are very light and strong, and the skin is
quite thin. With the foam interior they are rather like a watermelon.


And you have extensive experience with hen's eggs the size of a planet?


No, but I have 15 years of melon planet experience. Mostly
Cannonballs, a few cantelopes and an experimental gourd project.
Hen's eggs are 28th century.

A water planet would be hot at the center.

I'm inclined to believe it, but then why does the ocean get colder as
one descends, while earth grows hotter?

Patrick Powers wrote:

Scott Robinson wrote in message . ..

[snip]

A water planet would be hot at the center.

I'm inclined to believe it, but then why does the ocean get colder as
one descends, while earth grows hotter?

AFAICT it's because colder water -- down to 4°C -- is denser than
warmer, and sinks. Great as the pressures get in the deep oceans,
they're insignificant compared to those in the interior of a planet,
at least as far as they affect convection &c.; I don't know how water
behaves under extreme pressure, but I can imagine it solidifying to a
degree, inhibiting convection and other transport mechanisms
sufficiently to trap heat in the core. But even if so, there would
remain a surface region where the usual regime, involving water in a
liquid state, allows heat to be carried upward from the depths.

--
Odysseus

On 17 Nov 2004 18:25:04 -0800, neurocratic malfunction wrote:
i know such a thing is not possible of ever existing, but suppose...

with a snap of a finger, planet earth turned into a giant watermelon.

what would happen?

How big a pumpkin cannon would you need to throw it?

--
It strikes me that out of real intellectual humility, Mr. Bush has
"drifted" into the boldest, most counter-intuitive of all the possible
courses of action: a project to re-align the United States explicitly
with every opposition force that can be found within the Middle East,
no matter how small, that aspires to democratic constitutional reform;
and to gradually manoeuvering the full power of the U.S. behind them. In
other words, truly digging to the root cause of terrorism: which is the
intellectual and material enslavement of the Arab and Persian masses.
- David Warren

Think of it this way: a watermelon crust can easily withstand a force
of 1 G. If that 1 G came from its own center, so much the better:
this is the direction from which a sphere is strongest. So a
watermelon the size of the earth with even a one-inch crust would not
collapse due to gravity. Heck, you can take a hen's egg and squeeze
the ends as hard as you can and it won't break.

You are forgetting issues of scale. As siz increases linearly, volume and
mass increase as the cube. This causes problems as things get bigger. Look
around and tell me how many watermelon shaped planets you find. You don't,
because at this scale, nothing is rigid.

As to an egg, again, there is the issue of scale. At this scale, it is not a
rigid crust. And, it is effectively flat at this scale.

The center's heat: I'm not sure. Much of the heat in the earth is due
to radioactivity. The ocean doesn't heat up the deeper one goes.

There are three different process being confused here. The earth's current
heat is due to radioactivity as you noted. The ocean does not get warmer
because there is nothing to heat it sufficiently. It does not compress
beyond tiny amounts and the coldest actually sinks downward, driving the
great oceanic currents.

A better analogy might be the formation of a star. As the cloud condenses,
compression produces heat. When it rises to a sufficient level, fusion
begins. The giant watermelon planet would also have some compression. How
much depends on how fresh it is. A fresh, fully hydrated watermelon planet
would be primarily water, which compresses little. One off of the vine for
some time would have voids to allow for lots more compression. Primarily,
you would have reshaping as it moved to a spherical form.

Clear Skies

Chuck Taylor
Do you observe the moon?
Try http://groups.yahoo.com/group/lunar-observing/

************************************

"CLT" not@thisaddress wrote:

You are forgetting issues of scale. As siz increases linearly, volume and
mass increase as the cube. This causes problems as things get bigger. Look
around and tell me how many watermelon shaped planets you find. You don't,
because at this scale, nothing is rigid.

Question for the physics geeks: would an Earth-sized (in smallest
circular cross-section), watermelon-shaped body of solid neutronium
remain watermelon shaped, or would its own gravity cause it to become a
sphere? What about the new thing that's even more compressed than
neutronium (the name of which escapes me, but I think it's basically
solid quarks).
--
Aaron Davies
Opinions expressed are solely those of a random number generator.
"I don't know if it's real or not but it is a myth."
-Jami JoAnne of alt.folklore.urban, showing her grasp on reality.

Odysseus wrote in message ...
Patrick Powers wrote:

Scott Robinson wrote in message . ..

[snip]

A water planet would be hot at the center.

I'm inclined to believe it, but then why does the ocean get colder as
one descends, while earth grows hotter?

AFAICT it's because colder water -- down to 4°C -- is denser than
warmer, and sinks. Great as the pressures get in the deep oceans,
they're insignificant compared to those in the interior of a planet,
at least as far as they affect convection &c.; I don't know how water
behaves under extreme pressure, but I can imagine it solidifying to a
degree, inhibiting convection and other transport mechanisms
sufficiently to trap heat in the core. But even if so, there would
remain a surface region where the usual regime, involving water in a
liquid state, allows heat to be carried upward from the depths.


Water under extreme pressu there are nine forms of water, most of
them solid, but I'm pretty sure the Earth's core is liquid. You could
look for "phase transition diagram of water" or something like that.