Of course there are deeper relationships. And, due to π being integrally tied up with circles, that makes circles "exist" even if there is no such thing as a "perfect circle". The two are inextricably linked.JimC wrote:I agree that π arises naturally in many phenomena, but I would argue that it does so because it is a vital component of circle geometry. All of its "arisings", if you trace the maths back, would derive from the circle in one way or another, which then forms one basal component of the more complex phenomenon. I can't see π being formed by several, independent mechanisms; or if it were, I would suspect deeper connections between the various occurrences.
All a circle (or a spere) actually "is" is the set of points equidistant to another point in two (or three) dimensions. That is where the deeper relationship lies. A circle is also the shortest, stable orbit of one object about another. An expanding sphere is also the limit of the influence of any single spacetime event.
Round things pop up everywhere and, when they do, π is not far behind!
