It's said that bitcoin people think outside the box, now, imagine in the future, do you think that there will be possible to move anything (including radio signals) faster than the speed of light?
Alcubierre’s idea: bending space-time in front of and behind a vessel rather than attempting to propel the vessel itself at light-speeds.
You need to put dark energy in front of your spaceship and nobody knows how to make some. We don't even know what is this stuff.
So, the universe is wast, perhaps there's already other civilizations that have created interplanetary communication technologies, perhaps we one day will get in touch with them, and start using their technology ?
Well, we
try to find them with SETI, but no results so far. There are also reasons to believe that it will be impossible to contact a civilization if it's more than about an hundred light-years away (the radio signal would be much too weak). We would be very lucky if more than one technologically advanced civilization had developed in such a small neighborhood, and in the same time frame.
Also, one day, our sun will stop shining, and by that time, if mankind is not extinkt, we would need to find somewhere else to live, and it would be logical to think that we would need to inhabitate more than one planet on our quest to inhabitate the universe. :p
Earth will stay inhabitable for about five hundred million years. That's a lot. IMHO, humanity as we know it will almost certainly NOT exist in ten thousand years. Or if it still exists, it won't matter much because it won't be the most intelligent life form anymore. Humans will be over-powered by machines, who might just keep them as pets or something. And for a machine, the concept of being "inhabitable" is much different than for a human.
Also, it's not unthinkable that in say a couple of hundred years from now, maybe before that we have bases with people living on mars, the moon and so on.
Human will not live on mars or the moon, for the same reasons nobody lives in Antarctica, Sahara or on deep ocean floors. We're just not built for that. Why would you like to spend tons of money to settle down in such an hostile environment, anyway?
In the future, there will probably be astronauts that will be willing to dedicate their entire life for space exploration, it is also possible to imagine that a giant self sustainable space station would travel through space, while hosting a complete and sustainable eco-system for hundreds or thousands of years until it finds an inhabitable planet.
We don't need to send humans for exploration. Robotic probes will do it as they currently do. If we send humans, it will mainly be symbolic, for fun essentially. Spatial hiking will be some kind of a very expensive leisure activity.