Space is for robots. Earth is for life.
Why are we so shortsighted? The future is an incredibly long time. If self-sufficient human settlements on, say Mars, are out of the question with our current level of technology and are unlikely in the next few centuries, does that imply they'll be just as unlikely in 10,000 years? Will our descendants be so stupid they won't be able to solve new technology challenges?
Today is not the end of history.
You can do the same thing with digging. Well, we can dig 10m down, why not 100m? Why not 10000m? Why not all the way through? I mean it's easy physics to show you can move between any two points on a planet through an evacuated tunnel with no energy price, so why don't we do it? Is it because the downers like me don't think we have the materials to actually build the tunnels, and that we'd have to spend a great deal of energy to cool them because the Earth's core is really hot, and if only we'd shut our cynical traps the dreamers would get 'er done?
I blame science-fiction for really and truly warping our intuition of what is physically possible. A small moon base is certainly possible, but does that mean a sun base is possible? No. Cars revolutionized transportation, and phones communication. Does that mean teleportation is possible? No. Do insights about spacetime make time-travel possible? Except in the Ted Chaing sense (where time-travel has a lovely, inevitable symmetry to it), no. Chemistry - so we can create matter from nothing? No. Theoretical physicists play games with math - so free energy from vacuum? No.
But nanotechnology? Yes. AI? Yes. Full control over the genome? Yes. It's not that I think history is over, it's just that our stories are misleading about which branches of history we can travel. No ancient thinking person really ever doubted the earth was round (because there are easy experiments anyone can do), and they didn't think that heavier-than-air flight was impossible (because birds). It's true a few believed faster-than-sound travel was impossible, but I don't think that was ever a majority view (could be wrong on that, though).
Back to space. Space sucks. I don't want to live there. The Expanse was/is a great show, and it's certainly more realistic than most space-faring SF -- but it is still deep fantasy. The impact of living outside of gravity and outside of the magnetosphere is enormous and even with perfect medicine it would be uncomfortable because of the atmospheric constraints. The Epstein drive is fantasy. It is admittedly more plausible than most SF drives, but still non-physical. Of course, the alien stuff is pure fantasy.
Places like Mars suck even more than space, IMHO. Mars is a lifeless, cold rock without atmosphere or light, or proper gravity. I mean, Mars right now is still infinitely worse off for supporting life than Earth in the worst case, struck by a 20km asteroid. Or post-Yellowstone caldera. Another way to put it, Mars could take 100 meteor strikes like that and be no worse off. That's how bad it is. (There wouldn't even be much of a nuclear winter since there's no atmosphere to keep ejecta suspended. Although maybe if you strike it just right and with the right rocks you could give it an atmosphere of sorts?)
So, there is hope for exotic effects! Quantum phenomena at scale is basically magic. Black holes are quite mysterious! So is the origin of the universe - and I believe, contrary to most, that cosmological questions could very well have practical applications. "Metamaterials" (a kind of cousin to nanotech) can open up a lot of cool options for building things. And so on.
But yeah I wish people would give up the childish Star Trek/Star Wars fantasies about the possibilities of technology and embrace the reality of what we know. I too want FTL, teleportation and sexy humanoid aliens to seduce as much as the next guy, but despite the aesthetics its fantasy. And while shows like The Expanse seem more real, they still sneak in enough fantasy to invalidate it. (I do appreciate them not abandoning kinetic energy weapons for the massless junk in other SF, though!)
Any attempt is at best speculation and at worst a fantasy. As you said, extrapolation from current trends quickly gets us into unbelievable territory.
I'm definitely not a religious person, but I do have faith they (future humans) will figure something out, if there's any incentive (survival, profit, ... fun?) to do so - unless our species goes extint first.
That's also why I do believe things SpaceX and others are doing are important. Not because we'll have a colony on Mars in a few decades (I don't think we will). But if we don't even start trying, it'll be awfully long before we get anywhere.
I get your gist, but I don't agree. The analogy I think of in this case is ancient Greece - let's say Athens. Imagine a precocious boy who discovers he can walk on the ocean floor by fitting an inverted bowl over his head and breathing the trapped air there for a time. He continues to innovate, and attaches a hose. He makes discoveries!
Thrilled by his success, he pitches the idea of making an underwater map of the entire Mediterranean! The benefits would be vast, to all the sciences, and would make the sea safer to travel. All the problems can be solved: too deep? Longer hose! With enough ships, enough diving bells, and divers, there is nothing physically impossible about doing this.
But of course, it's not worth doing. Such a project could have consumed an entire economy indefinitely. To attempt it prematurely would have been folly - a folly we call pride. The Mediterranean Sea is not that big compared to other bodies of water on Earth, but it is still truly vast, effectively infinite, on a human scale. Even with modern equipment a full mapping of the Med is a truly daunting task.
SpaceX is doing excellent work changing the economics of delivering goods to orbit by a factor of 10x or 100x. But even so, we are still at the diving bell level - or even worse - when it comes to space exploration and colonization. I DO NOT believe it makes sense for us, the modern Athenians, to even start spending enormous sums mapping the Med with sailboats and diving bells.
So we'll build carbon-neutral space launch platforms. We'll figure out asteroid mining and space manufacturing. We'll grow beyond Earth because we will never, as a whole, accept death.
The engineering people talk about won't get us to self-supporting colonies on other celestial bodies.
What will, someday, is re-engineering ourselves until we become the extraterrestrials we've failed to find in the rest of the solar system.
It's analogous to how life emerged from the water on Earth. Every cell in our bodies (I'm plagiarizing a little, but I don't recall what) carries a bit of primordial ocean with just the right saltiness, because we really are still sea creatures with built in life support. But at the same time, we aren't adapted to the open sea and can't go back.
Some day there will be creatures descended from us, maybe called human and maybe not, who have changes at the cellular level or lower to deal with the harsh environments on other planets. That carry their own atmosphere and ozone layer with them. And they probably will not be able to return to Earth.
The litmus test will be whether a place is survivable with stone-age technology. Otherwise it's only a matter of time until a colony is wiped out due to some unforeseen technology failure.
And to do that we could start with the smallest thing that could make a living on the moon. The moon is a good placeholder for "space" - and is arguably a lot kinder than most places. (If the OP is right about Mercury, then it would be somewhere between Earth and the Moon in terms of friendliness.)
Earth's moon is far more extreme than the most extreme life we know of could endure[1]. Look at that table of extremophiles - and recognize that the Moon is easily 10x worse than the worst environments.
There are only two resources available to potential life on the Moon: rocks and sunlight. There are indeed some interesting atomic elements in the rock[2], but you'll notice two elements not in the list: no hydrogen, no carbon. I don't see a feasible way to bioengineer the Rockeaters from "The Neverending Story" but even if you could you'd have to make sure they didn't need to breath or stay warm. And I'm pretty sure that such creatures would be closer to robots than biological life, anyway.
(Note that life in empty space is about as harsh as you can get - you have sunlight, but without mass you can't grow or reproduce, and without gravity you can't move effectively or sustainably. You are forced to lose mass with every movement. As you move away from a star you lose even sunlight, and it's not clear what you could do out there except cool down to ~4K in equilibrium with cosmic background radiation and hope that you warm up enough to come back to life someday.)
[1] https://en.wikipedia.org/wiki/Extremophile
[2] https://en.wikipedia.org/wiki/Moon_rock#Composition : mostly: Aluminum, Iron, Magnesium, Calcium, Silicon, Oxygen, Titanium
The idea of "stone age" tech being enough to survive implies an ecosystem that maintains itself.
A rogue planet could have heat and water if it was reasonably large or part of a multiple body system with tides. C.f. Enceladus and Io. Then there's Titan.
We're maybe 70 years away from being a multi planet species if technology keeps advancing at the same rate.
We just need better ways to get into space. If the Sabre program works out or we figure out fusion power we'll be ready to roll in 20.
Or we could figure out self replicating robots. Nature has been doing it a billion years so we already know it's possible.
Or, just create a robot species in our image to explore for us. And hope they keep their meaty parents around and happy
There's multiple paths for humans to get off the planet. Out of the solar system, maybe not. But it's damn hard to predict farther than 100 years into the future
Indeed, I think this is the most plausible scenario. And I think a robot civilization would want to keep Earth living and breathing for reasons other than sentiment. Life has been around a long time, and has solved problems a robot civ hasn't thought of yet. Also, there are certain catastrophes that could wipe out a robot civ, but not Earth (and vice-versa) so we could be each other's backups. Of course, Earth is just an absolutely beautiful place, worth maintaining for that reason alone. And the bots might even choose to maintain pockets of life elsewhere in the solar system, just in case, but that is a very different scenario to the one in the OP's article.