In what context where vector calculus concepts, such as:
first developed? I had assumed they were developed first in fluid dynamics, since the flow of water is concrete and important, and from there applied to electromagnetics, which are obviously more abstract. However, I can find no source to support this.
This post suggests they were first developed for quaternions, ie pure math, and only later applied to physics. My question still stands: What were the initial physical applications and how did they spread?
Related but not duplicate: How were vector calculus nabla ∇ identities first derived?