Thinking about that led to the thought that, other than within realm of the theoretical, there's no such thing as circle?
They may look like circles, but if measured minutely enough -- not quite exactly equidistant here, and here too, and just a littlest smidgen right there...
I don't know for sure, but I'd imagine that not even electrons hold a pure (orb) circle for very long, since by nature they're so jiggly.
That's putting too fine of an edge to it, I admit.
It's like trying to drag concept of a circles into in other theoretical realms, then wandering around with them, attempting to try them for size on stuff that has component of velocity --which makes it impossible. It won't hold still long enough to be able to slap a test gauge on "it". It's a rigged game, I tell ya'...
Factor in there being an ever-so-slight trembling shakiness to even the steadiest of human hands, and I give up.
Reminds me of a story allegedly coming from among a Native American Indian tribe, who when doing bead work on moccasins or what-have-you, would purposefully introduce some noticeable if but slight flaw into the pattern, doing so in acknowledgement there be only One --the Creator--- whom possess perfection.
I don't know if it's a true story, but it appeals to my own senses of reality.
Electrons are even worse. Their orbits are described as probability functions, and only a few of the orbits can be described as spherical.
Stupid, even thugh I've taken partial differential equations and matrix algebra and tensor analysis. Never quite got the idea if finite element analysis, though.