Together these changes brush the computational complexities under the rug, and leave only the descriptive power of the laws:
* "the gradient of the electric field is proportional to the amount of electric charge"
* "the curl of an electric field is always zero"
* "the gradient of a magnetic field is always zero"
* "the curl of a magnetic field is proportional to the size of the electric current plus the amount of change in the electric field with respect to time".
As Wikipedia notes: "Mesopotamian, Indian and Chinese mathematicians are all known to have discovered the theorem independently and, in some cases, provide proofs for special cases."
An interesting take on "modern", meaning "the last 3 decades or so", which is like millenia in the IT industry...
Or are you referring to some other difference?
Work clothes, suits and hazmat wear also don't change their design every three months.
Like cycles in economics, climate, fashion, etc.
For example, John Shutt has developed a non-trivial theory of F-Expressions (vau-calculus)[1] and a language named Kernel that employs them[2]. Neither has received wide attention yet, but the Lisp renaissance of the past few years is still young...
[1] https://www.wpi.edu/Pubs/ETD/Available/etd-090110-124904/unr...
[2] ftp://ftp.cs.wpi.edu/pub/techreports/pdf/05-07.pdf
It took years to develop approaches to garbage collection (the earliest prototypes used bump allocators and crashed when they exhausted a heap), years to finalize the syntax of the language (you'll notice that the "maxwell's equations" are written using M-Expressions, a syntax for the language which was discarded for ease of implementation and later rationalized because homoiconicity can be handy), decades to realize how important lexical scope (versus dynamic) is to maintaining encapsulation. Modern Lisps are substantially different in syntax and semantics from these earliest ideas; we're just still calling them Lisp.
It's very easy to make Lisp look elegant when you brush all the implementation details under the rug.