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Comment by keiferski | Hacker News Reader

I don't know, I can't help but feel like nearly all of our solutions to contemporary problems involve space travel, specifically self-contained space travel (i.e., when spaceships become within an order of magnitude as affordable as houses or automobiles.) The universe is essentially limitless from a human point of view, so to be perpetually stuck on Earth seems like a failure of perspective.

- Oppressive government controlling you or your land? Move elsewhere in the solar system.

- Resource extraction destroying natural environments on Earth? Asteroids and other planets have far more natural resources and long term, it is inevitable that mining will be off-planet.

- Overpopulation? On a universal scale, there is no such thing.

Obviously most of these won't be solvable in 20, or 50, or even 100 years. But, they seem conceivably doable in 200, or even 150. In the greater scheme of things, this is a very small amount of time.

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Yeah in a perfect world maybe. The problem is that we're facing issues on a relatively short term here and if we don't manage to solve them there will be no way out. If stopping the current destruction of our home planet is 1/100 difficulty, terraforming Mars would be 90/100, leaving the solar system for an already hospitable planet would be 101/100.

We're much better are polluting and creating useless gadgets than we're at long term meaningful technological innovation.

> Oppressive government controlling you or your land? Move elsewhere in the solar system.

Migrants can't pay for proper boats to cross the Mediterranean but they'll pay for interplanetary travel ?

I'd be skeptical of just assigning problems an arbitrary difficulty level and then comparing them directly. Better to recognize larger, uncontrollable trends and then see if they can be nudged into the right direction, or adjusting your actions to piggyback them. This is sort of what the whole "accelerationist" thing was about, back in the 90s.

In other words, forcing the entire world to address some contemporary issues (like overpopulation, for example) might be more difficult than just accelerating the production process that makes space colonization possible (thus solving the problem).

> Migrants can't pay for proper boats to cross the Mediterranean but they'll pay for interplanetary travel ?

I had in mind more the early settlers to America, and early frontier America itself really. When "leaving Earth civilization" becomes conceivably affordable/doable for a small group of people and/or with investment, it will happen.

> I'd be skeptical

> When "leaving Earth civilization" becomes conceivably

> it will happen.

You're less skeptical than I am apparently. Leaving the solar system and terraforming planets isn't really comparable to crossing an ocean in a boat. What you describe would be a best case scenario and for now it is pure sci fi.

> forcing the entire world to address some contemporary issues (like overpopulation, for example) might be more difficult than just accelerating the production process that makes space colonization possible (thus solving the problem).

Yeah it might, or it might not, by the time we'll figure it out it'll be way too late to revert. It's the "move fast and break things" mentality, it's fine in software but we already know how it ends up when you apply it to other systems...

We just don't know how fast and how bad it'll get if we continue, you have to be extremely optimistic to think that ignoring the real world, already existing, problems to focus on hypothetical non existing solutions is the way to go. (and we're not even focusing on solutions, we're focusing on shitty half assed money making gimmicks such as electric cars and autonomous vehicles, which aren't solving anything on a global scale)

https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/SR15...

https://www.un.org/sustainabledevelopment/blog/2019/05/natur...

https://en.wikipedia.org/wiki/Ocean_acidification

https://www.climate.gov/news-features/understanding-climate/...

I like your way of thinking.

But remember, even with sublight travel, to populate the entire galaxy would take only a few million years. Including say a thousand years to rebuild the capability in each new colony. It grows geometrically you see, and there's no beating that.

So on a Galactic scale its certainly possible to overpopulate, and in the blink of a cosmic eye (a million years). In fact that's a powerful argument for 'we must be alone', since it hasn't happened already (not getting radio signals from every star system everywhere).

It's not a powerful argument for 'we must be alone', because it's an equally powerful argument for 'space colonization is nearly impossible.' You're saying things are "certainly possible" but you don't have a shred of evidence to support that belief. It's more likely that you're vastly underestimating the cost of maintaining a life-supporting ecosystem independent of the benefits of a billions of years of evolutionary adaptation.

That thinking is about a decade out of date. The number of expolanets that are in the habitable zone grows geometrically. Some think every star has some planets. Simple chance makes it possible to find agreeable destinations nearly everywhere.

And 'evolutionary adaptation' is irrelevant. We can change ourselves (are changing ourselves) genetically already. That will only increase. The result will be a species more adaptable than any in a billion years. If it has the will to colonize other planets, it certainly can.

'A shred of evidence' is really not hard to find, if we aren't needlessly negative and contrary.

> Some think every star has some planets.

20 years ago, before we had direct evidence of exoplanets, we had evidence from the spectrum of stars that about 80% of the ones which had grown large enough to swallow any of their planets had previously had gas giants.

A decade out of date? It'll take you 30,000 years to reach the nearest star at the rate of the fastest moving object ever constructed by man. If anything any of us are talking about are able to be out-of-date in a mere decade, the whole premise of this discussion is flawed beyond measure.

All of the resiliency that you've seen in life is due to the fact that the environments to which we're adapted are uniform. Oceans everywhere are nontoxic and water. Air everywhere is mostly clean and breathable. There is no example of life being resilient under conditions as varied as other planets. We are only able to adapt within the confines of our clean-room Earth. We can't even adapt to the bottom of the ocean or Antarctica.

Optimism isn't going to overcome 6 orders of magnitude of error.

Not a single correct thing in that, I believe! Life on Earth has evolved to live in hundreds of dissimilar environments. Heavy salt is toxic, yet fish manage the ocean. Yellowstone has life in mud pots at hundreds of degrees. Air doesn't exist underground yet bacteria thrive there. Hell, there are living things on the surface of the space station.

To get people to tolerate more salt, we'd have to have a fish's ability to regulate it. Ok, genes for that. Air issues? Filters, microstructures to migrate particulates out, baffles (like many creates already have). Deep-ocean pressure? Only a couple of issues there, and certainly life thrives at the bottom of the ocean.

It's not optimism; its simple observation of what we have already on Earth in existing life forms.

And 30,000 years changes not a thing. The log of 1 Trillion base 2 is 39. In 40 generations of space colonization, that's 40 times 30,000 times however long it takes to rebuild the capability on each colony. In a dozen million years the galaxy would be covered. Its 20B years old. So, nobody's tried it yet.

>In 40 generations of space colonization, that's 40 times 30,000 times however long it takes to rebuild the capability on each colony.

Assuming each generation survives. Stop making that assumption, and see how many ways there are for you to reach a similarly empty universe.

>It's not optimism; its simple observation of what we have already on Earth in existing life forms.

I wish you'd observe that none of Earth's lifeforms have colonies on other planets. Goldfish didn't colonize other worlds, is that then a strong argument that Goldfish don't exist?

What you're saying makes no sense: just because animals can colonize a single planet over many generations does not mean they will be able to colonize an entire galaxy in even less time.

Again, not true. Geometric growth can't be dismissed. Even if 90% didn't survive, it just takes (a little) longer.

How the hell is a 10% survival rate "not optimism?" Try a trillionth of a percent. It makes an astronomical time difference.

>I wish you'd observe that none of Earth's lifeforms have colonies on other planets. Goldfish didn't colonize other worlds, is that then a strong argument that Goldfish don't exist?

I would not be so sure about dolphins. ;-)

You're ignoring what I believe to be the most important point: how do we know that is actually possible to build an interstellar colonial vessel?

Or, to bring a concrete element to the question: all known rocket fuels require some nonrenewable Earth resource. How much fuel does it take to launch a vessel built with currently-known technology that would be capable of landing a living human being on a hypothetical planet around Alpha Centauri? And what does that fuel number look like, when expressed in terms of "years of current resource extraction" (or, somewhat more audaciously, percentage of known proven reserves)?

To my knowledge, interstellar colonization is flat-out impossible with current technology. (I'd argue that even intrastellar colonization is impossible, rather than impractical). Arguing that we should discount this non-knowledge of how to do it when explaining why it hasn't happened to our observation is irresponsible to me.

Well, the ideal chemical rocket fuel is hydrogen + oxygen - eq. the two things that make up water. Thats perfectly renewable once you pump some energy into it to split water into the two.

Methane + oxygen popular in the new generation of rockets is not much different, you basically add some carbon to the process & Methane can be made on Mars from local resources.

Best fuel for nuclear thermal rockets is again hydrogen, abundant everywhere.

Current Ion Engines run on noble gases, but supply does not seem to be a problem so far.

Sure, the uranium needed for Orion and Nuclear Salt Water rocket indeed is not really renewable but given the performance &opening the way to grab more of it from space make it a non-issue as well.

Every first world economy on Earth is already below replacement rate right now, we're not going to see some out of control population disaster scenario.

The more likely situation is that we need to A. get over our racism and xenophobia to use the population bombs going off in less developed countries to replace our populations that don't want to replace themselves and B. eventually start seeing human replacement as a societal cost that will need to be afforded in some way once the entire world is sufficiently developed to go below the natural replacement rate. At which point we get to set population targets and hold our numbers stable.

A is something that we should have been doing for 30 years now. B is going to be of concern next century after the population plateaus.

You are really underestimating exponential growth in your assertion that there is no such thing as overpopulation on a universal scale. If human population is doubling say, every century, then the time it takes for us to go from populating the earth to the entire galaxy in less than 4000 years[1], and from there to the entire universe in less than another 4000.

[1]: There are a few trillion planets in our galaxy. If you asssume the mean population supported by a planet is within an order of magnitude of what Earth can support the math holds.

Well, the universe is likely infinite, so no, there's really no such thing as overpopulation on a universal scale.

But talking about humans populating the universe is also meaningless, since the speed of light and expansion of the universe means we can't reach anything but a tiny fraction of it, and by the time we have the technology to travel quickly enough to even begin contemplating intergalactic journeys only a fraction of a fraction will be within reach.

s/universe/universe observable to humans/

>If you asssume the mean population supported by a planet is within an order of magnitude of what Earth can support the math holds

Theoretically if you shred earth for material and build habitats from that, it can definitely support much more than a magnitude more.

| I don't know

You certainly don't. You have a serious misunderstanding of the sheer scale involved in space travel. Its great to think that an individual will be able to pack up their space car in 200 years and move on out west to mars or something, but there literally wont be anything to do but crash land once you get there, or maybe if you're lucky, walk around for a few hours before suffocating.

Im not saying it's not possible to colonize another planet, but I am saying that disintermediated space travel in the sense of a Heinlein novel is overwhelmingly a pipe dream.

Terraforming planets in a meaningful way anytime soon is a pipe dream, but someone in 200 years very much could get in their space car and go to a different space habitat. O'Neill cylinders have already been mentioned here.

There's no scientific reason we are aware of that would make living in artificial habitats worse than living on a planet, and a lot of reasons that it would be better. It's just that those of us talking now live on a planet, and find the idea of continuing to live on a planet comforting.

Someone born on an O'Neill cylinder or similar will likely have no such compunctions.

>Someone born on an O'Neill cylinder or similar will likely have no such compunctions.

"You can't really control the weather, it varies by the year and there is earthquakes and flash floods at random ? Not to mention no Free-Fall-Racing ? How the hell have you survived till now down there ??"

> There's no scientific reason we are aware of that would make living in artificial habitats worse than living on a planet, and a lot of reasons that it would be better. It's just that those of us talking now live on a planet, and find the idea of continuing to live on a planet comforting.

But this is just so obviously backwards. Your assumption is that an artificial environment would be monotonically better to live in than the one in which we evolved? There's simply no evidence for it, and if you take a look at how the people on the ISS live, a strong argument against it. As for scientific caveats...well bone density and muscle mass loss in low-g (pretty much every target location for colonization) are fairly well substantiated, as well as the cosmic ray issue, which is even harder to deal with.

https://en.wikipedia.org/wiki/O'Neill_cylinder

These are possible (if not remotely practical) with our current level of materials science and solve for both the gravity and cosmic ray/radiation issues. There's lots of other designs that should go larger, but require further advancements in things like carbon nanotubes, etc. to be possible.

As for why it would be better - control. No worries about pollution. No worries about earthquakes, volcanoes, or other natural disasters. No droughts, no hurricanes, no tornadoes.

No one is talking about living on space stations like the ISS - we're talking about building purpose built large scale structures that are designed from the ground. And these aren't things that are the realm of science fiction authors and futurists with no grounding in reality or physics - they're things that have been and continue to be seriously researched by NASA and other space agencies.

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