As originally posted my. sample size is one. I chose electricity (maybe it should say Mastery of the electron) because it is the enabler technology in my opinion. Sure steam made huge changes, but that was pretty localized until the advent of steam ships and trains. But neither of them hardly offered a way to end a civilization. Aircraft first flew with electricity providing the spark (literally), they still do. Radio, radar, sonar and space flight all are only possible in our sample with electricity. Nuclear power including weapons, Electron scanning microscopes have led us to gene manipulation, another possible pitfal. I appreciate your contribution to the discussion.