what is the roundness ratio of a sphere?

Question

I mean the sphere?? is it its volume or the surface area or what... thanks a lot

Answer 1

There are at least three definitions, but by all, the answer is 1.

In astronomy, it is the ratio of the minor to major axis of a body. On a sphere, all axis have the same length.

In this application to the Earth, it is the polar diameter divided by the equatorial diameter. On a sphere, both are the same:
http://books.google.com/books?id=TQnY-sAENi8C&pg=PA39&lpg=PA39&dq=roundness+ratio&source=web&ots=0gl1hWKnrV&sig=Ml0mwqPxqKzbeoogkjGLRwlIZgg

In geology, it is a measure of how round the corners and edges are. On a sphere, the ratio would be 1:
http://books.google.com/books?id=te9FMHjOR4oC&pg=PA512&lpg=PA512&dq=roundness+ratio&source=web&ots=j1uhulLp-t&sig=avsuBF7d-CtdIyMn6FzQrU0XRoA


The real question is why didn't you do a web search first?