> To explore But then why start a colony? If you're just looking around, then the massive investment to build a comfortable habitat isn't worthwhile. I think t

> To explore But then why start a colony? If you're just looking around, then the massive investment to build a comfortable habitat isn't worthwhile. I think the incentives just don't line up; that's my Fermi paradox answer. I especially think it's unlikely that anyone would set off on an exploration where they were going to die of old age before ever seeing anything. > We've got millions of years to work out how. What if it isn't possible? The sheer scale involved suggests there's nothing to be done. It is a bonfire exponentially larger than all the mass we can conceivably bring to bear upon it in any way. When it burns out, it burns out. Moving the planet is a little more feasible [1], but doing it with solar sails would take about a billion years, even if the sail was 19x the diameter of Earth. An ion drive would be snappier, but we'd have to have effectively unlimited energy to make that happen, and we'd have to eject about a sixth of the Earth's mass from outside of the atmosphere on some sort of planetary gimbal. [1]: https://www.sciencealert.com/this-rocket-scientist-explains-how-we-could-hypothetically-move-the-planet https://www.sciencealert.com/this-rocket-scientist-explains-... > how can you possibly know what the limits will be Oh I can't. But there are limits, and we'll hit them eventually. The most obvious limits are energy and mass. We obviously can't do anything that would require more mass than exists in the solar system, and the ceiling for practically accessible mass for any given purpose is likely much lower. Some elements are quite rare. There may not be that much energy to go around. There are also likely soft time limits: A project that takes ten thousand years might simply be beyond us politically. Some tasks, like full comprehension of the human brain, might simply be too complicated to ever be realized. The longer you think about it, the more plausible limitations materialize.