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mgb_phys

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## Main Question or Discussion Point

A question came up on a maths Q+A site about the possibility of wrapping a string around a sphere.

http://mathoverflow.net/questions/8091/is-it-possible-to-capture-a-sphere-in-a-knot

The obvious engineering solution is to just make a net and put the sphere in, and there are a bunch of photos of fishing floats where this is done.

But if the rope is frictionless you can always slide a knot along to make a hole big enough for the sphere to fall through

The answers descend into a lot of maths-speak I can't follow - but there is an interesting general question, can you tie any sort of knot in a frictionless rope?

http://mathoverflow.net/questions/8091/is-it-possible-to-capture-a-sphere-in-a-knot

The obvious engineering solution is to just make a net and put the sphere in, and there are a bunch of photos of fishing floats where this is done.

But if the rope is frictionless you can always slide a knot along to make a hole big enough for the sphere to fall through

The answers descend into a lot of maths-speak I can't follow - but there is an interesting general question, can you tie any sort of knot in a frictionless rope?