He pitched the problem in terms of both existing physics and of new '21st Century' ideas inklings of which had somehow trickled down into the 20th Century and t

He pitched the problem in terms of both existing physics and of new '21st Century' ideas inklings of which had somehow trickled down into the 20th Century and that physicists needed new mathematics to deal with them (I hope I've not mangled his words too much). It has definitely been said that "String theory is part of 21st-century physics that fell by chance into the 20th century.". I can recall seeing variations of that quote in a few different books over the years. Interestingly though, a quick Google search (maybe I should have asked ChatGPT?) shows attributions to both Witten and Daniele Amati. So I'm not sure who said that particular bit first.