The Complexity of Unit Systems and Dimensional Analysis in Physics

Stephen Wolfram answers questions from his viewers about the history of science and technology as part of an unscripted livestream series, also available on YouTube here: https://wolfr.am/youtube-sw-qa

Questions include: Recent thoughts on history - Was SMP or Mathematica inspired by LISP and what are the pros and cons of LISP-like languages? - Was the decision to have Mathematica untyped unlike something like Lean (proof checker) a good decision for usability or would you do it differently today? - Type-checking always felt like dimensional analysis. - Was your idea to use "transformations on symbolic expressions" a sudden insight after reading, say, Schönfinkel on combinators, or did it follow from working out atoms of computation, something else? - What is the history of lazy evaluation? - Have you come up with any new theories of human reasoning from working on Mathematica and computation?