Nicolas Nassim Taleb is one of the greatest author of non-fictional that i read. He wrote some books about philosophy, psychology and matemathics called "The Black Swan", which is a masterpiece for modern thinking.
This was Iustin Capră, and is known for inventing a machine that was the first jet-pack. I think he was a master-mind, but he was unlucky, to be born in a country that hadn't had the possibility to create and to fabricate, what their genius minds could create.
Lost notes were found from the deceased comedian George Carlin predicting Americans would vote for Donald Trump as President of the United States. In a desk drawer were notes written a month before his death in
This is Alexander Fleming, the discoverer of Peniciline. I think this personality is great because his invention led to a new era in modern medicine, and peniciline transformed medicine and pharmacology in a Revolutionary way.