I have asked a questions about the definition of average speed and its application on this site, but it get closed. It should be acceptable, because physical quantities are the basic of mathematical analysis. Without it you can do nothing meaningful. So it is natural to seek their application.

How about if someone come up some special definition and want to know the application?

• How about if someone someday come up with the idea of spin-correlation and ask whether it may can show the phase transition of some models?
• How about if they ask where can they apply the vortex-correlation?
• Is the size of spin cluster has applications?
• Is the average of loop length has any correlation to the magnetization, superconductivity, etc?

Why we cannot ask such kind of questions in this forum? This fit well here as physics questions, so we may seek the others opinions on the subject and someone might help each other.

My question is clear and the definition is unambiguously, don't you think that it should be allowed?