If there is life, chances are it's either got completely alien technology, (hence why they cant communicate despite the fact that we've been broadcasting for the past 70 years: 70lys!),
Or they aren't developed yet (we will probably enslave/contain them if we get the chance (zoos))
Or they're just ignoring us (they will/have already(?) contain/enslave us if they wanted to (zoos))
Living on another planet? In our solar system? Not likely.
Venus is like a primordial Earth, so we'd need to speed up it's malting process somehow ;)
Mars is what Earth will one day be, so though it's got a steady environment and light gravity, we'd need to bring our own soil.
The Moon? Outpost or mining center at the most. Chances are that people will want to go on holiday there, but not live there due to the side effects of low g. (Unless healthcare extends to the moon (haha fat chance))
World Uniting? I'd say we'll be getting globalisation in the next 50 years or so, but too quickly for everyone to agree. Western culture has already spread as far as Iran and China, but this is happening too quickly for the officials to like, and so war may ensue(?)
If you're just talking about the potential of the human race; it's big, but too big.
Chances are we'll splash out all over the galaxy as soon as we get the chance. Then we'll create new frictions with these colonies (lack of mobility of education and health) and we'll kinda reset to how we are now, that's if, IF, colonisation happens before mobility of services (so in this case, FTL)
If FTL is invented, then everyone can maintain instantaneous communication with each other, and so outsourced colonies wont feel abondoned when they encounter health problems and appeal to Earth for help.
(Imagine: without FTL, aid would arrive long after a significant proportion of the colony is dead! Friction would be imminent.)
· 10 years ago