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I would prefer it if we made human settlement of the oceans a reality first. Human settlement of space has health problems that are not yet solved such as visio

by ryao 10y ago

I would prefer it if we made human settlement of the oceans a reality first. Human settlement of space has health problems that are not yet solved such as vision damage from zero gravity environments and brain damage from cosmic radiation. http://www.space.com/25392-manned-mars-mission-astronaut-vision.html http://www.space.com/25392-manned-mars-mission-astronaut-vis... https://www.rt.com/document/57fc69bac46188c6758b4599/amp https://www.rt.com/document/57fc69bac46188c6758b4599/amp Making underwater habitats is far more practical in the short term. Experience in making closed environments for human habitation of the ocean would be useful when the problems with space exploration are solved.

tonmoy 10y ago
New places to colonize because we are running out of livable land is not the main issue. In case of an extinction level disaster, most land/ocean based humans may be wiped out. Having a "backup" colony on a different planet is needed in this regard. And we are talking about colonizing another planet, so zero G vision problems would not be that much of an issue I guess.
- prewett 10y ago
  What disaster are you imagining that takes out an underwater colony? It'd be completely sealed off from the water, so you could vaporize the entire ocean (unlikely) and atmosphere and it would still be okay. The only thing I could see affecting an underwater colony would be an earthquake, but I'm having trouble imagining an earthquake big enough to wipe out all surface life.
M_Grey 10y ago
Underwater you have gravity, access to our biosphere, food, water, you can make air and make fuel. In space... well... The issue though, is that people want what's out there, they want to mine asteroids and somehow that laudable goal has been conflated with colonizing another gravity well in some minds.
- science4sail 10y ago
  One thing that I've always wondered is why space colonization focuses so much on planets. It seems like orbital platforms would both fix the low-gravity health issue (spin the platform) and provide easier access to lucrative resources (you can hit asteroids without dealing with getting in/out of gravity wells).
  - tonmoy 10y ago
    1. It is much easier to land on/get into the orbit of a planet. For example, transfer from low earth orbit to Mars requires a delta V of about 4.3 km/s. Now to get into Mars' orbit, this needs to be reduced to about 3 km/s (rough napkin-top calculation, take with a grain of salt). However if you want to "stop" at a massless orbital platform/asteroid, you would have to reduce all 4.3 km/s (without any aerobrake assist). 2. If we assume an orbital platform is like a ring (similar to Halo), and if the diameter of this thing is 2km, then it would need to spin very fast (70m/s). This is okay, until you realize, that so much speed means a lot of difference in gravity from the floor to ceiling. For example, a man who is 2m tall, would feel 1g on his feet and about 0.95g = 9.3m/s^2 on his head. The difference in g would give rise to different health issues. You could make the station bigger, but then it would be probably better to stick to a natural body that is similar size instead
    - abecedarius 10y ago
      I thought delta-v from LEO to Mars was over 6km/s? There are near-Earth asteroids at much lower delta-v. https://www.planetaryresources.com/2015/08/how-we-choose-our-asteroid-targets/ https://www.planetaryresources.com/2015/08/how-we-choose-our... gets into some of this. At the 1km radius you give, a 2m human would have head at 0.2% lesser acceleration than feet. Am I miscalculating? Note that 1g is just one place in the design space, though an attractive one for a big enough station.
      - tonmoy 10y ago
        I am probably wrong with the 4.3 number (compiled the first result from google without double checking). And it won't be 0.2%, the head's speed would be 0.2% of the feet, but since g=v^2/r, the gravity difference would be about 3%
eddieh 10y ago
Floating settlements in the atmosphere of Venus would be interesting. There is at least an argument to be made about settling Venus before Mars. Likewise, I'm not sure why Mars is the first choice, especially when the moon is so close.
azov 10y ago
Life adapts. If we put enough people out there and give it enough time, evolution will take care of health problems. Especially given that cosmic radiation should increase mutation rates. Of course, this is not a short-term project.

by ryao 10y ago

tonmoy 10y ago

New places to colonize because we are running out of livable land is not the main issue. In case of an extinction level disaster, most land/ocean based humans may be wiped out. Having a "backup" colony on a different planet is needed in this regard. And we are talking about colonizing another planet, so zero G vision problems would not be that much of an issue I guess.

prewett 10y ago
What disaster are you imagining that takes out an underwater colony? It'd be completely sealed off from the water, so you could vaporize the entire ocean (unlikely) and atmosphere and it would still be okay. The only thing I could see affecting an underwater colony would be an earthquake, but I'm having trouble imagining an earthquake big enough to wipe out all surface life.

M_Grey 10y ago

Underwater you have gravity, access to our biosphere, food, water, you can make air and make fuel. In space... well... The issue though, is that people want what's out there, they want to mine asteroids and somehow that laudable goal has been conflated with colonizing another gravity well in some minds.

science4sail 10y ago
One thing that I've always wondered is why space colonization focuses so much on planets. It seems like orbital platforms would both fix the low-gravity health issue (spin the platform) and provide easier access to lucrative resources (you can hit asteroids without dealing with getting in/out of gravity wells).
- tonmoy 10y ago
  1. It is much easier to land on/get into the orbit of a planet. For example, transfer from low earth orbit to Mars requires a delta V of about 4.3 km/s. Now to get into Mars' orbit, this needs to be reduced to about 3 km/s (rough napkin-top calculation, take with a grain of salt). However if you want to "stop" at a massless orbital platform/asteroid, you would have to reduce all 4.3 km/s (without any aerobrake assist). 2. If we assume an orbital platform is like a ring (similar to Halo), and if the diameter of this thing is 2km, then it would need to spin very fast (70m/s). This is okay, until you realize, that so much speed means a lot of difference in gravity from the floor to ceiling. For example, a man who is 2m tall, would feel 1g on his feet and about 0.95g = 9.3m/s^2 on his head. The difference in g would give rise to different health issues. You could make the station bigger, but then it would be probably better to stick to a natural body that is similar size instead
  - abecedarius 10y ago
    I thought delta-v from LEO to Mars was over 6km/s? There are near-Earth asteroids at much lower delta-v. https://www.planetaryresources.com/2015/08/how-we-choose-our-asteroid-targets/ https://www.planetaryresources.com/2015/08/how-we-choose-our... gets into some of this. At the 1km radius you give, a 2m human would have head at 0.2% lesser acceleration than feet. Am I miscalculating? Note that 1g is just one place in the design space, though an attractive one for a big enough station.
    - tonmoy 10y ago
      I am probably wrong with the 4.3 number (compiled the first result from google without double checking). And it won't be 0.2%, the head's speed would be 0.2% of the feet, but since g=v^2/r, the gravity difference would be about 3%

eddieh 10y ago

Floating settlements in the atmosphere of Venus would be interesting. There is at least an argument to be made about settling Venus before Mars. Likewise, I'm not sure why Mars is the first choice, especially when the moon is so close.

azov 10y ago

Life adapts. If we put enough people out there and give it enough time, evolution will take care of health problems. Especially given that cosmic radiation should increase mutation rates. Of course, this is not a short-term project.