# Where will the cloth fold? [closed]

Here's a picture: There is a planet where there is no air, and nothing else there at all except the force of gravity and a surface. On this planet, there is a single post, placed perfectly perpendicular to the ground. Now imagine a circular cloth, made out of a material that doesn't experience any forces other than gravity, electromagnetic force between atoms, and the strong nuclear force. Lets say you dropped this cloth from about a foot above the post. The cloth is perfectly flat and is not wrinkled in any way.

How would the cloth drape/fold over the post?

• Does the Planet rotate on its axis, if so what is the latitude? Does the cloth fall so that the center of the circular cloth falls on the post? Is here any solar wind? May 3, 2015 at 18:11
• This is your second "assume unphysical symmetry and then then try to disambiguate the situation with physics" question. The answer to these is always going to be the same: you will not actually have that level of symmetry and the system is sensitive to the atomic scale asymmetries that are present. May 3, 2015 at 18:13
• I'm voting to close this question as off-topic because you are asking an open-ended, hypothetical question: “What if ______ happened?” which is additionally about a situation that will not occur in reality. May 3, 2015 at 18:26
• What is the location of the post in relation to the cloth?
– LDC3
May 3, 2015 at 18:56
• @LDC3 the post is directly below the center of the cloth. May 3, 2015 at 18:58

Original facetious answer involving a ghost cloth

Since the material

doesn't experience any force other than gravity

the cloth will fall through the post, through the planet, come out the other side and then fall again. It will oscillate about the planet's centre, exhibiting perfectly undamped simple harmonic motion, assuming the planet has constant density with radius.

You need the cloth's atoms to experience electromagnetic forces if you want it to be unable to pass through the post, and probably want the constituents of their nuclei to experience the strong nuclear force as well so they behave in a way that's at least somewhat reasonable...