Humankind discovered time travel in the early twenty-second century.
It wasn’t on purpose, as it were. As it happens with many scientific discoveries, sometimes you are looking for one thing, then another gets in the way with results you are most definitely not expecting. Take Viagra, for instance. Or antigravity associated to superconductors.
The time travel process was discovered during experiments in locative media and augmented reality applied to elevators.
Anyway, it happened at a very interesting time in History. The human race had suffered a long period of wars, diseases, and, even though it was far from global peace and understanding, now it seemed to be entering, if not a golden age, at least a time to start dreaming and making plans. A post-virtual environment embedded in antigravitational elevators as part of an ambience designed to soothe and distract people during the long risings and falls through the more than two hundred floors of the arcologies seemed as good a place as any to give this age a jumpstart with such an invention.
As it were, the environment turned out to be not only a virtuality, but a time displacement device which took its occupants to a very different set of coordinates from what was expected originally. Suffice it to say that, when the doors of the elevator opened, the dumbfounded passengers were not in Kansas anymore—at least not in 2113 Kansas anyway (for the building really was located in that American state), but in a shabby building in 1999 with mere fifty floors.
After a few minutes of absolute confusion and, in some cases, total denial, the discombobulated denizens of the future returned to the elevator and told it to get them back to where they had come from. Fortunately, it was able to do so.
The First Prototype, as this elevator is called today, is on permanent exhibition at the Smithsonian—but not before the post-virtual environment was carefully dissected and examined in search of what made it behave so unexpectedly. Something to do with quantum teleportation, apparently, but the details were never disclosed to the public. (Perhaps, as some media pundits said, because even the scientists didn’t know how the hell such a thing happened.)
Be as it may, time travel rapidly became a fad, and—who could expect that?—a sort of escape valve for the stressed citizen. People cherished the idea of traveling to a fine, quiet time, not to any turning point in History where they could be attacked by terrorists or die in an earthquake, for instance. Nobody tried to alter past in order to change the future.
One of these Safe Years—as they were called—was the very first year reached by the environment: 1999.
Now, there were some dissenters who argued that even 2001 could be considered a Safe Year, in every other city than New York, but the majority preferred to stay on the safe side. It was a year when anything could happen—except that it didn’t.
Again, dissenters begged to differ—they said that it all depended on whose view it was, for in 1999 the following things happened: a 6.1 Richter scale earthquake hit western Colombia, killing at least 1,000, a fire in the Mont Blanc Tunnel, in the Alps, killed 39 people, closing the tunnel for nearly 3 years, a magnitude 5.9 earthquake hit Athens, killing 143 and injuring more than 2,000. Another quake, this one Richter 7.6, killed about 2,400 people in Taiwan; not to mention the Kosovo War.
Accusations of Anglocentrism ensued. (An argument much discussed was that Earth is a really big planet, and they recognized that many things happened outside the Anglo-American sphere of influence—most of the things that happened in the world, actually. Earth had come a long way in globalization, and, after all, the time travel was discovered by a team of French, Indian, and Brazilian scientists in Accra, Ghana, so that was expected.)
The second phase of research and development was most focused in the matter of geopolitics. Using systems of coordinates and geolocation tools, they managed to make the time-traveling environment travel around the world as well as in time, so people could visit other cities instead of their own in different historical periods. It would seem to be most practical and convenient—until the second prototype was lost just outside Earth’s orbit. (You must be painstakingly accurate in order to compensate the traveling of Earth itself around the Sun and across the galaxy, eventually. Not something to be taken lightly.)
Then it was pointed out that this apparent flaw could be used as an advantage. It would take a lot of effort and calculation, but nothing a quantum computer couldn’t handle.
Again, 1999 was a crucial year, much to the dismay of critics and naysayers, but for other reason than the historicity criterion: it was pointed out that the time travel mechanism would need a slingshot effect to dislocate the prototype adequately through the space-time grid and do it safely enough with the maximum degree of precision and minimum risk.
1999 just happened to have the Y2K bug. Of course, it could have been any other thing, but why bother and try to invent it when the bug was already in place, just waiting for a chance to be useful? The “rollover” from 99 to 00 didn’t play havoc with data processing as it was feared, but the transition to 2000 in the digital systems would jumpstart the mechanism and power the slingshot through this now called Zero Year and enable the time-traveling environment to go anywhere in the space-time continuum. And they were not thinking only of Earth.
Humankind discovered interstellar travel in the mid-22nd Century.