In 1900, man had not invented airplanes. WW1 brought us fight planes and tanks that well.. sucked. lol. WW2 brought us jet planes, modern tanks, and guided missles. In 1950, space was still a dream. We can visit space pretty much whenever we want now, and if you are rich you can even buy a ticket on a space shuttle. In the early 80s we had personal computers, and if you had money you could have one. Hell, I had a laptop in the early 80s. I had a computer before windows. It was rare, but my mom was a programmer for IBM. In just 25 years, computers have went from what was essentially a digital typewriter that you could play very basic(basic, get it? lol.) games and programs on to the six core 3.3 ghz computer with 12gb of memory and terabytes of harddrive(mostly porn) that I am using right now that cost less to build than my yearly beer allowance.(fuck you, I like beer). Cars are driving themselves around us, semis now play follow the leader without a driver. We couldn't imagine today 25 years ago, it is near impossible to know how insane our abilities will be in 50 years.
Come to think of it... that is why the unibomber started killing computer people. Technology increases exponentially. In 50 years we might not even be human anymore.