You can start here: http://en.wikipedia.org/wiki/Wick_rotation http://en.wikipedia.org/wiki/Wick_rotation and there was this on HN some time ago https://news

You can start here: http://en.wikipedia.org/wiki/Wick_rotation http://en.wikipedia.org/wiki/Wick_rotation and there was this on HN some time ago https://news.ycombinator.com/item?id=8377680 https://news.ycombinator.com/item?id=8377680 Though I didn't find Scott Aaronson to be as clear as the professor who finally showed us the Wick rotation. Unfortunately he passed away a few years back right after having missed being awarded the Nobel prize by an inch. https://en.wikipedia.org/wiki/Nicola_Cabibbo https://en.wikipedia.org/wiki/Nicola_Cabibbo