6 ms·

I'm with Carl Sagan. Visit? Yes. Settle? Not yet. Like it or not, for the moment the Earth is where we make our stand. Not that there's anything wrong with wa

by Cushman 15y ago

I'm with Carl Sagan. Visit? Yes. Settle? Not yet. Like it or not, for the moment the Earth is where we make our stand. Not that there's anything wrong with wanting to go to Mars as a hobby, as a tourist-- if that's how you want to spend your billions, fine. But I worry that too many impatient sci-fi lovers see space travel as some way to escape from the problems of Earth, which it will never be. If we can't figure out how to live sustainably on Earth, humanity will perish long before we have any realistic possibility of emigrating.

JoeAltmaier 15y ago
You say that with authority. Care to share your reasoning? Folks went as far (in terms of travel time) to desolate places to make a future before. You are likely descended from some of them.
- rbanffy 15y ago
  None of them had to take their own air.
  - ceejayoz 15y ago
    Mars colonists won't need to, either.
    - ars 15y ago
      They might not take it, but they would have to make it. Almost no free oxygen on mars. But making oxygen (from rocks presumably) uses lots of energy (electricity - it's basically the same process used to make aluminium from ore).
      - JoeAltmaier 15y ago
        Which is abundant on Mars as solar energy, with its thin atmosphere.
        rbanffy 15y ago
        Not that abundant - Mars is 1.4 AUs from the sun and receives about half the solar energy we get on Earth. Also, keep in mind that, while the atmosphere is very thin, there are very intense sandstorms that can block the sun for months at a time.
        JoeAltmaier 15y ago
        The thin air mitigates the distance issue somewhat. Anybody know how much? Solar intensity reduces by the square if distance. If the advantage of thin air multiplies available sunlight at ground level, it may be close to break-even or even better?
      - ceejayoz 15y ago
        Rocks? No. Water ice. Solar powered electrolysis, and you get to use the hydrogen for fuel too.
        ars 15y ago
        Water ice? No. Water ice is much harder to find than rocks. It's more useful for drinking, and the binding energy of hydrogen is greater than the metal in rocks. (I.e. it takes more energy to get oxygen from water ice than from rocks.) And how exactly do you plan to use the hydrogen for fuel? What's your oxidizer? Other than the very same oxygen you just worked so hard to make in the first place. Also, although the most common metal from rocks is silicon, iron is not uncommon on mars, so if you pick your rocks properly you get iron as a waste product, which you can use for building.
        deleted 15y ago
        [deleted]
- Cushman 15y ago
  No human being has ever settled in a place which was not previously the habitat of a billion years of successful organic life-- and we have failed to settle in a number of places which are. To think of Mars as just the new New World is a romantic idea, but there is no basis for the comparison. Populating another world will be the most significant undertaking of humanity by orders of magnitude; to assume it can be done while it remains to be seen whether we can survive as a species on a planet with an atmosphere which is exactly what we breathe, which is made of as much water as we are, of the same phase ours is, where food grows in the ground all by itself and we are nearly completely protected from debris large and small, and with a legacy of billions of years to prove it can be done-- well, I'd ask to know your reasoning.
  - JoeAltmaier 15y ago
    We're smart. We live almost entirely in structures and cities that are very remote from the idyllic world you describe. When was the last time you saw your food grow? There are technological hurdles to living on Mars, but not much we already don't know how to handle. Food, water, air - that's the minimum, and thats not all that hard given raw materials and energy, which is abundant on Mars.
    - Cushman 15y ago
      ...really? How many cities run on recycled air produced from rocks? On recycled water from melted permafrost? With 100% solar power? Eating entirely food grown using the same? With the risk that if any ine of those things fails, everyone living there will certainly die? To this you compare the fact that I eat cows fed grass from a hundred miles away, brought to me using energy we literally just dug out of the ground? That I drink water piped from a giant lake all of halfway across the county? If anything, you support my point: what passes for "remote" and "inhospitable" on Earth is unbelievably luxurious by the standard of anywhere else. Even Death Valley gets rain. Even Antarctica has oxygen. Talk to me about your plans for a self-sustaining colony in one of those places, and then we can talk about how many times -- how many orders of magnitude -- harder and more expensive it will be to do the same thing on Mars.
ceejayoz 15y ago
Right now, an asteroid could wipe out humanity with pretty minimal warning. There's something major to be said for at least a small self-sustaining colony somewhere else.
- greeneggs 15y ago
  Except we can defend the earth from an asteroid for probably five orders of magnitude less money than establishing a self-sustaining colony somewhere else. And if self sustaining is all you need, setting up a self-sustaining colony a mile underground is also five or six orders of magnitude cheaper. I can't think of any risk to humanity where going to the moon or Mars makes sense as insurance.
  - ceejayoz 15y ago
    > Except we can defend the earth from an asteroid for probably five orders of magnitude less money than establishing a self-sustaining colony somewhere else. If we find out about it decades or centuries out. If it's a year out when we spot it, there's very little we can do with current technology to head it off (asteroid disaster movie plots notwithstanding). > And if self sustaining is all you need, setting up a self-sustaining colony a mile underground is also five or six orders of magnitude cheaper. It's also much more accessible by desperate refugees trying to get in as the planetary disaster approaches.
    - philwelch 15y ago
      It's also much more accessible by the planetary disaster itself, be it some sort of pandemic or war.
  - gammarator 15y ago
    "Five orders of magnitude less" than the cost of the Apollo program is $20 million [1]. Current large space telescopes and underground labs cost of order $2 billion, only 1/100th of the cost of the Apollo program, so I don't think your suggested alternatives are as cheap as you think. What makes SpaceX important is that they've rethought the design and manufacturing process to make their rockets far cheaper than others to date. If you bend the cost curve enough, surprising things become reasonable. [1] https://xkcd.com/980/ https://xkcd.com/980/
troymc 15y ago
I'm with Tsiolkovsky: "A planet is the cradle of mind, but one cannot live in a cradle forever." usually cited as "Earth is the cradle of humanity, but one cannot live in a cradle forever."
pjscott 15y ago
Is that just a fancy rhetorical flourish, or do you actually expect "living unsustainably" to potentially cause our extinction? If so, I would be interested in hearing a mechanism.
- philwelch 15y ago
  By definition, if you cannot live sustainably, you cannot sustainably live. Though sustainability, more or less, is about sustaining current populations and quality of life; most failures of sustainability won't extinct the human race, they'll just kill a lot of people off and deprive us of the massive amounts of energy needed to maintain our present quality of life.
  - tomjen3 15y ago
    Whenever I hear that argument I want to scream. The logic flaw is so clear: It is only unsustainable at current technology levels. The way we lived in 1900 was unsustainable then, but we could survive like that with 2012 tech no issue (less coal burning, improved sanitation, etc). In 100 years it will be sustainable to live like we do today.
    - philwelch 15y ago
      The goal should be that in 100 years, it will be sustainable to live like we will 100 years from now.
  - yew 15y ago
    If the definition of sustainability that you are using is "sustainably living" then it isn't [insert ideas associated with the sustainability movement here]. Not automatically, anyway. If all we care about is continuing to live (excepting the limitations imposed by entropy) then continuously importing resources from somewhere else is a perfectly valid solution. For that matter, no amount of efficiency will ever eliminate the necessity of importing resources. Pushing that necessity into the future is probably a good idea, of course. Continuing to live is not all I care about. But mature space infrastructure would positively contribute to doing just that, even if a colony on Mars might not in and of itself.
gammarator 15y ago
Musk said in a Q&A that he views it as cheap insurance.

by Cushman 15y ago

JoeAltmaier 15y ago

You say that with authority. Care to share your reasoning? Folks went as far (in terms of travel time) to desolate places to make a future before. You are likely descended from some of them.

rbanffy 15y ago
None of them had to take their own air.
- ceejayoz 15y ago
  Mars colonists won't need to, either.
  - ars 15y ago
    They might not take it, but they would have to make it. Almost no free oxygen on mars. But making oxygen (from rocks presumably) uses lots of energy (electricity - it's basically the same process used to make aluminium from ore).
    - JoeAltmaier 15y ago
      Which is abundant on Mars as solar energy, with its thin atmosphere.
      - rbanffy 15y ago
        Not that abundant - Mars is 1.4 AUs from the sun and receives about half the solar energy we get on Earth. Also, keep in mind that, while the atmosphere is very thin, there are very intense sandstorms that can block the sun for months at a time.
        JoeAltmaier 15y ago
        The thin air mitigates the distance issue somewhat. Anybody know how much? Solar intensity reduces by the square if distance. If the advantage of thin air multiplies available sunlight at ground level, it may be close to break-even or even better?
    - ceejayoz 15y ago
      Rocks? No. Water ice. Solar powered electrolysis, and you get to use the hydrogen for fuel too.
      - ars 15y ago
        Water ice? No. Water ice is much harder to find than rocks. It's more useful for drinking, and the binding energy of hydrogen is greater than the metal in rocks. (I.e. it takes more energy to get oxygen from water ice than from rocks.) And how exactly do you plan to use the hydrogen for fuel? What's your oxidizer? Other than the very same oxygen you just worked so hard to make in the first place. Also, although the most common metal from rocks is silicon, iron is not uncommon on mars, so if you pick your rocks properly you get iron as a waste product, which you can use for building.
      - deleted 15y ago
        [deleted]
Cushman 15y ago
No human being has ever settled in a place which was not previously the habitat of a billion years of successful organic life-- and we have failed to settle in a number of places which are. To think of Mars as just the new New World is a romantic idea, but there is no basis for the comparison. Populating another world will be the most significant undertaking of humanity by orders of magnitude; to assume it can be done while it remains to be seen whether we can survive as a species on a planet with an atmosphere which is exactly what we breathe, which is made of as much water as we are, of the same phase ours is, where food grows in the ground all by itself and we are nearly completely protected from debris large and small, and with a legacy of billions of years to prove it can be done-- well, I'd ask to know your reasoning.
- JoeAltmaier 15y ago
  We're smart. We live almost entirely in structures and cities that are very remote from the idyllic world you describe. When was the last time you saw your food grow? There are technological hurdles to living on Mars, but not much we already don't know how to handle. Food, water, air - that's the minimum, and thats not all that hard given raw materials and energy, which is abundant on Mars.
  - Cushman 15y ago
    ...really? How many cities run on recycled air produced from rocks? On recycled water from melted permafrost? With 100% solar power? Eating entirely food grown using the same? With the risk that if any ine of those things fails, everyone living there will certainly die? To this you compare the fact that I eat cows fed grass from a hundred miles away, brought to me using energy we literally just dug out of the ground? That I drink water piped from a giant lake all of halfway across the county? If anything, you support my point: what passes for "remote" and "inhospitable" on Earth is unbelievably luxurious by the standard of anywhere else. Even Death Valley gets rain. Even Antarctica has oxygen. Talk to me about your plans for a self-sustaining colony in one of those places, and then we can talk about how many times -- how many orders of magnitude -- harder and more expensive it will be to do the same thing on Mars.

ceejayoz 15y ago

Right now, an asteroid could wipe out humanity with pretty minimal warning. There's something major to be said for at least a small self-sustaining colony somewhere else.

greeneggs 15y ago
Except we can defend the earth from an asteroid for probably five orders of magnitude less money than establishing a self-sustaining colony somewhere else. And if self sustaining is all you need, setting up a self-sustaining colony a mile underground is also five or six orders of magnitude cheaper. I can't think of any risk to humanity where going to the moon or Mars makes sense as insurance.
- ceejayoz 15y ago
  > Except we can defend the earth from an asteroid for probably five orders of magnitude less money than establishing a self-sustaining colony somewhere else. If we find out about it decades or centuries out. If it's a year out when we spot it, there's very little we can do with current technology to head it off (asteroid disaster movie plots notwithstanding). > And if self sustaining is all you need, setting up a self-sustaining colony a mile underground is also five or six orders of magnitude cheaper. It's also much more accessible by desperate refugees trying to get in as the planetary disaster approaches.
  - philwelch 15y ago
    It's also much more accessible by the planetary disaster itself, be it some sort of pandemic or war.
- gammarator 15y ago
  "Five orders of magnitude less" than the cost of the Apollo program is $20 million [1]. Current large space telescopes and underground labs cost of order $2 billion, only 1/100th of the cost of the Apollo program, so I don't think your suggested alternatives are as cheap as you think. What makes SpaceX important is that they've rethought the design and manufacturing process to make their rockets far cheaper than others to date. If you bend the cost curve enough, surprising things become reasonable. [1] https://xkcd.com/980/ https://xkcd.com/980/

troymc 15y ago

I'm with Tsiolkovsky: "A planet is the cradle of mind, but one cannot live in a cradle forever." usually cited as "Earth is the cradle of humanity, but one cannot live in a cradle forever."

pjscott 15y ago

Is that just a fancy rhetorical flourish, or do you actually expect "living unsustainably" to potentially cause our extinction? If so, I would be interested in hearing a mechanism.

philwelch 15y ago
By definition, if you cannot live sustainably, you cannot sustainably live. Though sustainability, more or less, is about sustaining current populations and quality of life; most failures of sustainability won't extinct the human race, they'll just kill a lot of people off and deprive us of the massive amounts of energy needed to maintain our present quality of life.
- tomjen3 15y ago
  Whenever I hear that argument I want to scream. The logic flaw is so clear: It is only unsustainable at current technology levels. The way we lived in 1900 was unsustainable then, but we could survive like that with 2012 tech no issue (less coal burning, improved sanitation, etc). In 100 years it will be sustainable to live like we do today.
  - philwelch 15y ago
    The goal should be that in 100 years, it will be sustainable to live like we will 100 years from now.
- yew 15y ago
  If the definition of sustainability that you are using is "sustainably living" then it isn't [insert ideas associated with the sustainability movement here]. Not automatically, anyway. If all we care about is continuing to live (excepting the limitations imposed by entropy) then continuously importing resources from somewhere else is a perfectly valid solution. For that matter, no amount of efficiency will ever eliminate the necessity of importing resources. Pushing that necessity into the future is probably a good idea, of course. Continuing to live is not all I care about. But mature space infrastructure would positively contribute to doing just that, even if a colony on Mars might not in and of itself.

gammarator 15y ago

Musk said in a Q&A that he views it as cheap insurance.