alt Hacker NewsWe don't know yet, of course, but I have the impression that the century in which things changed most was the century from about 1865 to about 1965. Stuff seems to have slowed down a bit since then. But it's all subjective, really: it depends on what you think is important.
1969 is a big year due to man landing on the moon. Cars becoming ubiquitous (they certainly were a luxury item well into the sixties here). 1970s gave us the integrated circuit and arguably the start of modern computing. 1980s the collapse of the Soviet Union, genetic research. 1990s: well, I can go on :P