# Thread: 1 potato, 2 potato,3 potato, 4....5 potato, 6 potato, 7 potato, more

1. Order of Kilopi
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## 1 potato, 2 potato,3 potato, 4....5 potato, 6 potato, 7 potato, more

What could be better for an Irishman (I'm mongrel Irish/Swedish/German), than a physics paper about potatoes? This guy gives a size limit for small asteroids to convert from roughly potato-shape to spherical with a new limit. neat. SEE:http://arxiv.org/ftp/arxiv/papers/1004/1004.1091.pdf pete
Last edited by grapes; 2010-Apr-11 at 12:08 PM. Reason: fixed url, left in celebration

2. Pete, you might like to clean up the link.

http://arxiv.org/ftp/arxiv/papers/1004/1004.1091.pdf

3. Abstract: The Potato Radius: a Lower Minimum Size for Dwarf Planets; Charles H. Lineweaver, Marc Norman

Summary: Gravitational and electronic forces produce a correlation between the mass and
shape of objects in the universe. For example, at an average radius of ~ 200 km – 300 km, the
icy moons and rocky asteroids of our Solar System transition from a rounded potato shape to
a sphere. We derive this potato-to-sphere transition radius -- or “potato radius” -- from first
principles. Using the empirical potato radii of asteroids and icy moons, we derive a constraint
on the yield strength of these bodies during their formative years when their shapes were
determined. Our proposed ~200 km potato radius for icy moons would substantially increase
the number of trans-Neptunian objects classified as “dwarf planets”.

4. Boil 'em, mash 'em, stick 'em in 'n orbit! (annoying flash. I warned.)

Interesting (from the discussion section)

Our derivation of the ~ 200 km – 300 km potato radius is related to the fact that on Earth,
earthquakes away from subduction zones are confined to depths less than ~ 30 km. This is
because plastic or ductile deformation of the rocks below 30 km is enough to relieve the
deviatoric stress, or pressure differences – the same ductile deformation that allow potatoes,
as they increase in mass, to become spheres.

5. Does it really talk about electronic forces?

ETA: I see their reference is Thompson's 1917 On Growth and Form, maybe that's where they get it. I have my copy around here somewhere...

6. I think in this case, the 'electronic' is in reference to all physical forces other than gravity.

7. I heard Charlie Lineweaver this morning (about 11:20am local time) on local ABC radio - he's quite a character! Very refreshing to hear someone talk with such enthusiasm on the radio.

Very interesting stuff!

8. Order of Kilopi
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Originally Posted by Spoons
I heard Charlie Lineweaver this morning (about 11:20am local time) on local ABC radio - he's quite a character! Very refreshing to hear someone talk with such enthusiasm on the radio.

Very interesting stuff!
Spoons. Agreed. I've read a number of his papers. He's good. pete

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