Comment by teachrdan

As to reaching 800+ Celsius: This is a solved problem on Earth because we have an effectively unlimited supply of oxygen and fuel. Neither of these conditions is true on Mars, unless you count the (very toxic to humans!) perchlorate in the soil. Extracting potable water from Martian soil would be a non-trivial task just in terms of energy needs, much less the task of making the water safe to drink.

The radiation issue is a bigger deal than you let on. I did not know about Ramsar. It's interesting! But this is a town of only 2000 with people who may have adapted to its higher levels of background radiation over generations. Our hypothetical Mars colonists will not have that luxury. And Ramsar has, on average, "only" 10x more radiation than we have on Earth -- still only 1/5th what we'd have on the surface of Mars.

I'd also point out that you seem pretty blase about the long-term risks of radiation. If we're talking about real colonization, we have to consider the risks of literal, multiple lifetimes of radiation -- not just how it might affect an average person over the course of a few years or decades.

> The idea of trying to just work out everything at home, and then have everything go perfectly is what I would call the meme

I apologize if it seems like I'm saying we need everything worked out. That is a miscommunication on my part. But we need some working prototype of what could work -- which we don't. We've never even succeeded in building a self-sustaining closed system on Earth! Where it should be easy! Because it's actually really really hard! And the craziest part is, literally no one is even trying!

If we can't make a self-sustaining closed system work here there is no reason to believe we could do it on another planet. I know SpaceX is everyone's favorite model of "go fast and break stuff", but there's many reasons why that does not apply to space colonization. The obvious first reason is that blowing up a rocket is not as serious as accidentally killing a space colony.

Another is the (imo mistaken) belief that rocked design is analogous to space colonization. I'd hazard that space colonization is maybe 1000x more difficult than designing a real big rocket -- which is admittedly very hard! But there are a bunch of extremely important and difficult questions that advocates for space travel -- maybe even you -- seem totally uninterested in solving and hand-wave away.

Resources will be scarce on a space colony, at least for the foreseeable future. What if a baby is born with a pathology that makes their care too expensive? Will they be left to die? Or will they have a right to live indefinitely? Will their parents be forced to get sterilized -- or have future fetuses aborted -- if they are at risk of producing more children with the same pathology? Who decides who gets sent home? It's simple if someone has an extreme psychic break with reality. But what if it's someone with severe depression? Or borderline personality disorder? Will the colony get to vote people off the island like the ancient Greeks sent people into exile? And what if a trip home might kill the person in question -- a particular risk for people who are born on Mars and never experienced gravity on Earth? Do future colonists have the right to give people an effective death sentence for being mentally ill?

These are obviously problems that exists here on Earth! But the consequences are entirely less dire here. A person with severe schizophrenia can live on the streets here in the US and pretty much no one gives a shit. But if this happens on Mars, and that person is using resources that are already in short supply (think of a world where there's only enough water to shower for a few minutes a week, or to subsist on only a bare minimum number of calories), people are going to care a lot. What happens next?