Sunday, December 11, 2011

A Supersized 'Earth'

Kepler-22b and inner Solar System
For your entertainment and edification, a short note on Kepler-22b, the exoplanet that has caused a flurry of 'habitable planet' stories in the mass media.

Is it actually habitable? The short and accurate answer is that we don't know. All we really know directly about Kepler-22b are its orbital period and size. But the first of these - not quite 290 days - yields an average orbital distance (semi-major axis) of 0.849 AU. In the Solar System that would fall close to midway between Venus and Earth.

The G5 parent star, however, is a shade smaller, cooler, and dimmer than Sol. Its estimated luminosity is 0.79 solar, meaning that the planet, at its average distance, receives just about 10 percent more light - and therefore heat - than Earth does. The planet must shed that heat by radiation, and a quick-and-dirty temperature estimate, based on the 4th power law of radiation to temperature, makes it 2.3 percent warmer than Earth - about six or seven degrees C.

In fact, the paper announcing the discovery comes up with an equilibrium temperature of 262 K for Kepler-22b, as compared to 255 K for Earth.

Radiative equilibrium is only a starting point for planetary conditions. How much heat a planet actually absorbs depends on how much light is reflected, or its albedo (0.29 for Earth). And its radiative temperature, in the IR, is measured at the top of any greenhouse layer in the atmosphere. The radiative equilibrium temperature is only a starting point.

But - assuming similar albedo and greenhouse heating to Earth - the surface temperature would also be a few degrees warmer than Earth. Which is easily inside the habitable range.

Pause here to note that most of what makes global warming problematic for our civilization is abrupt change in climate, not a somewhat warmer climate per se. An Earthlike planet with stifling tropics but mild subarctic zones would still be eminently habitable for humans.


Now for the caveats. For one, in spite of the cool illustration above (via Sky & Telescope) we do not know Kepler-22b's orbital eccentricity. Most extrasolar planets, unless so close in that their orbits have been tidally circularized, have notably more eccentric orbits than Earth does; this one could be searing hot at periastron, freezing cold at apoastron.

And we do know Kepler-22's size, 2.38 Earth radii, so it cannot really be very Earthlike at all. The radius corresponds to a volume 13.5 times Earth's. If it is primarily rocky its mass is proportional, with surface gravity well above 2g. On the other hand it could be a 'water giant,' with roughly earth-sized rocky core and a hydrosphere thousands of miles deep. Ocean is far too weak a term.

Earthlike it is not, whatever its composition. But it is hard not to speculate. Suppose that a rocky core has a radius of 1.38 x Earth's (and probably a bit denser), with a hydrosphere above.

Planetary mass is then close to 5 Earth masses. Surface gravity is about 0.9 g, and low-orbit velocity is around 11 km/s - similar to Earth's escape velocity. Getting back off after 'landing' on the hydrosphere would be tough, but not as tough as getting there in the first place, since it is 600 light years away.

So ... speculate!




Bonus science destructiveness news: Thanks to regular commenter 'Thucydides,' five cataclysmic events to think about.

86 comments:

Jim Baerg said...

For some Science Fictional worldbuilding of planets, that are earth-like only if you define the word broadly, but which are quite habitable, see:
http://www.worlddreambank.org/P/PLANETS.HTM

Rick: "An Earthlike planet with stifling tropics but mild subarctic zones would still be eminently habitable for humans."

See Dubia for what Earth might be like after the warming & the descendents of the survivors have
settled above the new sea level & at higher latitudes.

See Lyr for a world about the size of Kepler-22b.

Tony said...

Rick:

"So ... speculate!"

I refuse to speculate on so little data. But having said that, it is an interesting datum noentheless.

Thucydides said...

I am curious as to what the properties of a global ocean thousands of kilometers deep would be. The water at the bottom would be under mega or gigapascals of pressure, currents and circulation would be much different (especially since there would be no land masses anywhere near the surface), even the tides might be different (depending on the local systems distribution of moons and other planets, as well as the eccentricity of the orbit around the sun).

OTOH, trying to live on an endless ocean would be something only a fish would appreciate, humans would have to bring their own ecosystems (and if it comes down to that, they may as well bring leave their own ecosystems in orbit and study the ocean from space).

Anthony said...

For an ocean that doesn't get appreciably hotter with depth, and a surface temperature of 20K, it will turn solid (ice VI) at 8,000 atmospheres (with 0.9 surface Gs, about 90 km depth). With a temperature gradient of around .4c per kilometer you might have an almost arbitrarily deep ocean, though at a certain point you're above the triple point and the term liquid becomes dubious.

Anonymous said...

=Milo=



Thucydides:

"even the tides might be different"

Would you even notice tides, without any not-being-pulled-by-the-tides landmasses to compare your position against?


"OTOH, trying to live on an endless ocean would be something only a fish would appreciate,"

Not even those. Sealife likes shallow waters, not deep waters.

The problem here is nutrients falling to the bottom, but the seafloor having trouble supporting life due to the lack of sunlight.

Anonymous said...

Any life on Kepler-22b would be radically different from life here on Earth: no matter what the surface is like, the fact that it is a world larger than Earth would mean very differnt evolutionary path; a world-ocean would probably spawn various lifeforms suited for life at different bands of depths;a more terrestiral world would have massive lifeforms crawling across the surface, hugging the ground to ride out nearly-daily hurricane force winds; a world with a very thick atmosphere might have creatures that spend all but the first and last day of their lives 'on the wing'; there are a vast number of posiblities.

Ferrell

Thucydides said...

Anthony answered a few questions, and my remarks about the tides was uninformed speculation that a strong enough tide might cause "mixing" of the various levels of the superocean.

If the tidal bulge is big enough to lift superfluid water from the deep layer into a lower pressure zone, then you would have some pretty spectacular events. Supersolid "ice" would be much less of an issue. Given the parameters above, tides would only be an issue if there was a really huge body nearby, which does not seem to be the case.

OTOH, irregular events like an asteroid or comet impact might trigger "mixing" events, with whatever results that would cause.

Jim Baerg said...

Re: really deep oceans.

There was a novella in Analog some time ago called _Waterworld_. Some explorers encounter a world like what eg: Ganymede would be like if thawed out.

One difficulty for the explorers is that the atmosphere is a few times thicker than Earth's & mostly O2, creating an enormous fire hazard for any equipment they send down. This is because there is photosynthetic like & the organic material produced tends to drift down, away from where it can react with the accumulating oxygen.

A well thought out setting & problems for the characters, who are well thought out themselves.

Tony said...

I'm having trouble accepting the whole water world concept. The latest thinking is that Earth's hydrosphere is the result of a combination of volcanic outgassing and comet impacts early in the history of the planet. It's hard to believe that that much water would survive that close to a star to accrete into a mostly water planet, or that there would be so much internal and external water to be added to an essentially nickel-iron body.

jollyreaper said...

track

Rick said...

A waterworld with a very deep hydrosphere would probably be an 'ice giant' that migrated inward, not a jumbo terrestrial planet. Gas giants certainly end up as hot Jupiters, so soggy tepid Neptunes don't seem unreasonable.

Presumably a terrestrial planet could also be a 'waterworld,' if it accumulates a few times more water than Earth, enough to cover its highest mountains. But that is just a moderately deeper ocean.

Interesting points about the lower layers of a deeeep hydrosphere - once it is above the triple point, it is not much like any stuff we're familiar with, neither 'water' nor 'steam.'

If the rocky and metallic core - larger than Earth - is geologically active, it will heat up until convection (presumably) in the hydrosphere carries heat toward the surface - possibly along with volcanic gasses?

Could this process carry nutrients up to the surface of the hydrosphere, supporting life there? Dead stuff carries nutrients down, but volcano-like activity brings it back up.

And how about sargasso-like mats forming on the surface?

Sheerest speculation, of course, and I have no idea how viable (or otherwise) any link in this chain of speculation might be.

Thucydides said...

Superfluid water is used as a powerful solvent, and has been touted as a means of rapidly converting bio oils into biodiesel, breaking down garbage into organic molecules and even converting pant waste into sugars suitable for ethanol production.

Once organic matter reached the superfluid level (either filtering down or being blasted into the layer by undersea volcanoes or delivered by impacting comets), it would be rapidly broken apart. IF there is life, it may well be mats of "bacteria" or swimming "worms" that can live off the energy of chemical reactions (something like the creatures that live near "black smokers" on Earth).

Tony said...

Thucydides:

"Superfluid...has been touted as a means of rapidly converting bio oils into biodiesel, breaking down garbage into organic molecules and even converting pant waste into sugars suitable for ethanol production."

I bet all the touts forgot to mention that the energy required to create and maintain industrially useful amounts of superfluid water is always going to be more than the net energy advantage realized from any subsequent chemical reactions.

Z said...

Well, if it's mostly rocky, at two g the average vertical relief might be a fair bit shorter. Nowhere on Earth do we have mountains that represent geological maximums (nor does Mars, though that's often quoted as the root cause of the massive valleys and volcanoes) but it contributes. If there were critters, they'd probably skew smaller too- scaling laws strike with added vengeance at two g. Probably balmy- more outgassing and more retention- whether or not that's tropical-balmy or Venusian balmy might depend on its cometary water complement- there's a model I've seen that suggests that stable tectonic subduction and emission processes, plus carbonate deposition, need water as a lubricant/solvent/proton donor- and you might need a lot to keep everything good and soggy. Squatworld vs. Venus++. Hmm.

I tend to think the waterworld has some stuff going for it, though. Others have pointed out that that far in, you might not find enough water- but it's also hard to find that much rock, and we have enough data points to suggest that wandering thanks to accretion drag is pretty common, otherwise we don't get the thousand-some hot Jupiters. If it's cool enough for an exotic ice crust, then you have oceans fifty miles deeps and not much rock to speak of, so life would depend on volcanism pumping in enough ions to make anything.

...Unless it goes full greenhouse and is a steam-cloaked supercritical furnace that is unfriendly to macromolecules, in which case it might be the most sterile place in the universe outside a star. Assuming not, it'd probably have pretty low biodiversity relative to Earth- without niche partitioning by geography and associates like runoff and salinity gradients and interesting currents, you essentially get the surface-to-depth light/marine snow nutrient gradient and the latitude temperature gradient, Coriolis-driven convection cells, and beyond that, it's one big ecosystem- though that's still plenty, of course. Just means that lots of niches are filled by one species across much of the planet, just like we see with big pelagic predators like orcas and sharks, for instance.

By the same token, higher taxa are liable to be big and migratory- oceans favors inverted biomass pyramids, you get trophic efficiency gains with big creatures, and there's no small space for them to fit through, and big seasonal shifts in the nutrient distribution occur in a medium where everything can cover ground. I would fully expect space whales- well, whale sharks, more likely, because everything airbreathing on Earth, including lungfish, had a lineage that spent time on land or nearly so. So probably no lungs and all gills.

If there's biota all the way down, it uses a distinct chemistry from that at the top. Pascalization is sterilization by pressure, and at 340 MPa for fifteen minutes, you can kill even the hardy extremophiles and spores and such- noncovalent bonds start to get wonky and proteins and nucleotides (and presumably other folded macromolecules useful for life) start misbehaving. That's only (ha!) three times the pressure at the bottom of the Marianas, much less a 90km ocean. Maybe the bottom is sterile, and there's a whole stack of filter feeders. Maybe it's weird life down there. Or maybe life is a seafloor-up process and there's no life to be found. Hard to say for now. We need spectra...

That's my top of the head, anyways. When are we sending our Orion-drive generation-ship submarines? :-P

jollyreaper said...


I bet all the touts forgot to mention that the energy required to create and maintain industrially useful amounts of superfluid water is always going to be more than the net energy advantage realized from any subsequent chemical reactions.


Inefficient one way might be more efficient another way. I don't know if this still holds true but it was alleged that solar panels wouldn't generate more lifetime power than they took to build in the first place. Probably not a good deal if you're planning on using them for primary power generation, i.e. running the solar panel factory but that's not even an issue if you're in an RV a hundred miles from the nearest electrical plug. It's just like charging my phone. Is the battery less efficient than wall power? Yes. And I lose energy in the conversion when charging and discharging. But is it more efficient for me than dragging around a 20 mile extension cord? Yes.

So it may well be that if we want to use biodiesel, we could use really cheap power to run the large, immobile conversion plant and the resulting biodiesel is just a more condensed form of energy useful for running the car around, the same way storing in batteries for an electric car is more efficient than trying to burn coal in the car.

jollyreaper said...

" I would fully expect space whales- well, whale sharks, more likely, because everything airbreathing on Earth, including lungfish, had a lineage that spent time on land or nearly so"

I thought that lungfish would have been more along the lines of catfish, capable of breathing and dragging across limited expanses of ground but mostly aquatic. Brief excursions, yes, but certainly not regular land living like certain species of crab.

What I find really fascinating is that some species of octopi are pretty adept at maneuvering around on land. There was a show on the Discovery Channel a while back speculating about what Earth would look like in the far, very far, and far out future. One of my favorite ideas was the arboreal tree octopus. I could see those tentacles becoming fairly adept at gibbon swinging!

Thucydides said...

The net energy use of using superfluid water is one factor, but there are some processes that couldn't work any other way.

Disposing of garbage and getting a partial payment from the sale of syngas generated in the process might make economic sense in certain areas, especially if alternative means are expensive or banned (like trucking garbage hundreds of miles to a landfill or incinerating it). The remaining costs can be covered by the "tipping fees" to use the facility.

In the case of the world ocean, if there is a superfluid region then it would be abiotic pretty much by definition, but if there is some sort of circulation out of the region via currents, tides, volcanic activities or other mechanism then there will be the exo version of a "black smoker" providing heat and chemical energy to any putative life forms in the ocean.

Jim Baerg said...

If the syngas is used to make liquid fuels for cars airplanes etc., that would be a way to use nuclear power to run things that can't be plugged into the grid.

Tony said...

The point I was making is that higher product yield at the process level would almost certainly be offset by the cost of a significantly more energy-intensive process. About the only advantage I could see would be where the opportunity cost of using all that energy is less than the opportunity cost of not forcing the process. But I can't think of any context in which that would be a major factor.

Z said...

jollyreaper- You're correct, hence the "nearly so." Lungfish don't go tromping through the jungle, but they only exist in the kinds of anoxic environments that can occur at the land-water interface- mud wallows you'd rather not filter through gills, brackish waters where abundant rotting vegetation sucks out the oxygen, seasonal pools that must be migrated between across land, and so forth.So maybe I should have said "everything with lungs on Earth spent time at, or crossing, the land/water interface." I mean, weirder things have happened- it's possible that you get some organism that starts spending time at the surface to recharge for sprint hunting or something, but it'd be somewhat surprising.

It's a relative triviality, but by the same token, said life probably wouldn't have swim bladders for buoyancy either, because swim bladders are evolutionary homologues of the lungs in lungfish. So the whale shark comparison might be even more apt- big fat deposits and lifting surfaces for buoyancy.

Anonymous said...

=Milo=



I just want to notice that a couple of people are are mixing up "triple point" with "critical point". The former marks the minimum temperature/pressure at which something is capable of being liquid, while the latter marks the minimum temperature/pressure where something is capable of being a supercritical fluid (AKA both and neither liquid and gas at the same time).

Confusingly, "superfluid" seems to mean something else than "supercritical fluid".



Rick:

"If the rocky and metallic core - larger than Earth - is geologically active, it will heat up until convection (presumably) in the hydrosphere carries heat toward the surface - possibly along with volcanic gasses?

Could this process carry nutrients up to the surface of the hydrosphere, supporting life there? Dead stuff carries nutrients down, but volcano-like activity brings it back up."


Well, it would have to be a pretty big volcano. Earth's hydrothermal vents aren't really noticeable from the surface.

I also note that while volcanic chemosynthesis creates localized hotspots of life, it doesn't seem to lead to any really large and sprawling ecosystems.

I don't know how plausible it is for the volcanoes to launch back to the surface nutrients that didn't directly originate from volcanic gasses.

Overall, I could see some biomass existing on an ocean planet, but it would still be a planet-wide desert (ocean edition). At least, this is the most reasonable interpolation from Earth's biosphere, where the deep sea is indeed desert-like compared to the shallows.



Thucydides:

"Once organic matter reached the super[critical?]fluid level (either filtering down or being blasted into the layer by undersea volcanoes or delivered by impacting comets), it would be rapidly broken apart."

Unless it has different biochemistry from us? Surely some chemical must be stable enough to survive there.

Thucydides said...

My understanding of the process (on Earth) is materials introduced into supercritical fluids are rapidly dissolved into smaller and much simpler molecules. Garbage becomes synthetic natural gas and CO2, for example, or complex organic materials get broken into simple sugars.

"Fish" or plankton that enters the zone would rapidly be dissolved into simple sugars and gasses, which leads me to speculate that if there is a process like a current or tide that can push materials out of the supercritical zone, these molecules than become available for chemical or organic processes to take place. The point where the supercritical water reaches a layer of lower density would (presumably) resemble a "black smoker" of superhot or boiling water saturated with chemicals.

If there is life, it may either utilize the chemical and heat energy directly, or may have to dive or send down tendrils into the zone to "feed". Speculating beyond this would have to be in technicolour...

Anonymous said...

=Milo=



Thucydides:

"My understanding of the process (on Earth) is materials introduced into supercritical fluids are rapidly dissolved into smaller and much simpler molecules. Garbage becomes synthetic natural gas and CO2, for example, or complex organic materials get broken into simple sugars."

Okay, but is this all complex molecules, or only organic materials?

Because some chemical bonds are stronger than others. Is supercritical fluid powerful enough to break apart even the ones much stronger than what we're used to (that are normally rejected as a basis for life due to being "too stable to participate in reactions")?


"If there is life, it may either utilize the chemical and heat energy directly, or"

Is there any organism on Earth that can actually feed on heat energy? (Humans with geothermal power plants don't count.) Even geothermal-vent-based ecosystems seem to be rely on volcanic gasses, not the heat itself. It seems to me that either heat energy is too sparse to be useful for life, or it's just too hard to harvest (since you can't utilize heat directly, you have to have a heat gradient to extract any energy).

francisdrake said...

A big thanks to Jim Baerg for pointing to the PLANETOCOPIA website!
http://www.worlddreambank.org/P/PLANETS.HTM

The amount of detail the author put into this is amazing, let alone considering he did not do it on a computer but re-painted actual Earth-globes to illustrate his concepts. Also the amount of detail and consequences in his theories is stunning.

Myself you might consider a kind of a map-o-maniac :) so I will probably spend the rest of the weekend reading through the contents of this site.

Jim Baerg said...

It will take a lot longer than a weekend to read through.

Enjoy.

Tony said...

Re: PLANETOCOPIA

The worldbuilding is actually pretty pedestrian. The obvious furry fetish stuff is more than a little disturbing. The dream expositions are even moreso.

Jim Baerg said...

Maybe I can more easily than you just ignore fetishes which don't happen to be my cup of tea, while being interested in other aspects of his worldbuilding such as his obsessions with the benefits of a multispecies civilization, or the effects of thicker air making flight easier.

Tony said...

Jim Baerg:

"Maybe I can more easily than you just ignore fetishes which don't happen to be my cup of tea,"

If they're hidden offstage, I can ignore those things too. When they're in your face -- then I think they say just as much as any words that are spoken or written on the page.

"while being interested in other aspects of his worldbuilding such as his obsessions with the benefits of a multispecies civilization, or the effects of thicker air making flight easier."

I think "obsession" is the perfect word for everything this person does.

WRT the "benefits" of multispecies civilization, I think the whole concept is just magical thinking. It's a naturally unstable situation.

WRT thicker air making flight easier, that's only true up to a point. Then it retards flight through excessive resistance to bodies in motion, no matter how streamlined they are.

And anyway, like I said, the worldbuilding is pedestrian. There's nothing there that hasn't been seen before. Even the kumbaya worldview is nothing new.

Thucydides said...

Hal Clement did some great SFnal world building with novels like "Mission of Gravity". There was another "team building" effort many years ago called "Medea: Harlan's World" (with Harlan Ellison as the principle editor, if I remember correctly), and authors as diverse as Greg Bear (Eon) and Frank Herbert (Dune) have also made some pretty interesting "worlds".

Speculation about the layout and nature of the "world" creates a stage (or movie set, if you prefer), but it is still up to the author to work out the implications of the "set" and then cast an interesting story there.

Using the few pieces that I have gotten from this thread, I would have the "stage" be the black smokers created where currents cause upwellings from the supercritical fluid zones. Human scientists will find this very interesting, but are constrained by the limits of their technology and the remote observation posts they need to set up in orbit around the planet. The story arcs and conflicts would probably take place in space among the various people in the orbiting ecosystems (especially since most of the sea life would be about as intelligent as what exists around our own black smokers). World building is fairly easy; story telling is the hard part...

Geoffrey S Hicking. said...

Obsessions like this can produce useful things sometimes. It looks like a useful introduction to the concept of literal world-building.

Jim Baerg said...

Interesting discovery here:
http://www.universetoday.com/92022/earths-other-moons/

I think they might be good practice for expeditions to larger NEOs & making use of asteroidal material.

Christopher Phoenix said...

If Kepler-22b is terrestrial, any life will have to be very squat and heavily built to withstand the high gravity. I suspect the scale law will limit the size of any living creatures on a planet with a 2g-plus gravity even more than it does on Earth.

Human explorers will probably have a problem with fainting in 2g-3g gravity fields, at least according to this article. Perhaps some sort of anti-g suit could help them?

http://www.pbs.org/wgbh/nova/space/gravity-forces.html

If Kepler-22b is a waterworld, the sailing might be good. You'll need a lander that can float, however.

@Rick- Sargasso-like mats of floating seaweed is a neat idea.

Do any of you remember The Voyages of Dr. Dolittle? The good doctor travels to a hollow island that floats because it has an air pocket in its interior called Spider Monkey Island. The island floats from place to place, drifting in the currents.

Here's my plan. Hollow out a metallic asteroid so that it is less dense than water. Make sure it is leak-proof. Dump it on a water giant. It should float, like a steel ship.

Place some dirt and plants on your new floating island. Find some spider monkeys and set them loose. Don't forget to bring some Jabrizi beetles (whatever those are). Build a spaceport and use Spider Monkey Island as an extraterrestrial tour destination.

I suspect there is some failing in my plan. Perhaps the hollow asteroid won't be strong enough to survive in a near-1g gravity field? Maybe it needs support struts on the interior...

Thucydides said...

More likely the powers that be will want the asteroid and its mass to make more space habitats instead.

There is your source of conflict: the Spacers oppose the diversion of resources to the planetary surface, wanting to expand their civilization in space, while scientists want to study the planet more closely, and others with different motives want to inhabit the planet rather than live in orbital habitats. The scientists join forces with the "anti orbitals", without realizing just what sort of people they are dealing with.

Christopher Phoenix said...

@Thucydides

Interesting speculation. However, there are a lot of resources to go around in space. One nickel-iron asteroid contains more iron then the human race has used in our entire history!!

Arthur C. Clarke discussed "planetary chauvinism", suggesting we shouldn't overlook giant space stations as habitation options. There is something appealing about living in a massive structure floating in deep space.

However, there are many people who want to settle other planets. Robert Zubrin thinks that Mars, with its abundant resources, is a much better place to colonize than the Moon or deep space.

I think the scientists will join forces with "orbitals" in your scenario. They wouldn't want much more than a few scientific expeditions to an exoplanet.

Even we do choose to settle habitable planets, I think some people will live on spaceships and stations.

Thucydides said...

People will follow their own agendas, and your scenario is just as valid as mine. Really, since speculation about the planet itself is difficult due to lack of data, it is perhaps more fun to speculate about how people will act/react to it. That's what can lead to good SF.

Tony said...

Christopher Phoenix:

"There is something appealing about living in a massive structure floating in deep space."

Only to somebody that doesn't have to do it.

Jim Baerg said...

I think the drawbacks would get less as the structure gets bigger.

I expect I would eventually get claustophobic in the ISS. An O'Neill colony would be big enough to allow for substantial variety in the available environments.

Tony said...

Jim Baerg:

"An O'Neill colony would be big enough to allow for substantial variety in the available environments."

If you have the resources to build an O'Neill colony, you have the resources to visit planets whenever you want to. And the interior of a tube is just not the same as a whole planet for variety and freedom. The only people who think that an O'Neill colony is plenty of room are city-dwellers who don't get what "room" really means.

jollyreaper said...


If you have the resources to build an O'Neill colony, you have the resources to visit planets whenever you want to. And the interior of a tube is just not the same as a whole planet for variety and freedom. The only people who think that an O'Neill colony is plenty of room are city-dwellers who don't get what "room" really means.


We all think that buy how much space do you experience in your daily life? Not counting vacations, just home, office, the commute, a few stores. It's probably not as much as you'd think at first.

Tony said...

jollyreaper:

"We all think that buy how much space do you experience in your daily life? Not counting vacations, just home, office, the commute, a few stores. It's probably not as much as you'd think at first."

I have 10,300 ft mountain across the highway from me. I see it out my front window every morning. Good luck building that into an O'Neill colony. I can go shooting with a high powered rifle just a couple miles from my house. Try that in an O'Neill colony. The north rim of the Grand Canyon is a day trip from where I live.

I know damned good and well what I would be missing.

jollyreaper said...


I have 10,300 ft mountain across the highway from me. I see it out my front window every morning.
Good luck building that into an O'Neill colony.


Giant picture window, all of the cosmos.

I can go shooting with a high powered rifle just a couple miles from my house. Try that in an O'Neill colony.


Depends on what you're shooting. If it's just recreational then you could do that on the giant-scale colonies. If you're talking about hunting or serious sports angling then no, that couldn't be replicated in a satisfying fashion.

The north rim of the Grand Canyon is a day trip from where I live.


How often do you go? Many SUV drivers talk about how they have the choice of doing all the stuff they see in the commercials but 99% of the time they're just commuting to and from work and the shopping mall.

I don't doubt that there would be people for whom orbital hab living would be a hellish sort of existence. But I'd wager for most it wouldn't be that much of a change.

Anonymous said...

=Milo=



Christopher Phoenix:

"If Kepler-22b is terrestrial, any life will have to be very squat and heavily built to withstand the high gravity."

If it has the same density as Earth, its gravity would be around 2.4 times Earth's, which is survivable by humans in most postures, although not necessarily for extended periods (I doubt there has been much research on this). The one posture where you'd have trouble is standing on your head, which doesn't come up all that much, and where the human tolerance is listed on Wikipedia as "2 to 3 g", so it's borderline tolerable. Limits for standing on your feet (5 g), lying on your front (12 g), or lying on your back (19 g) are much higher. (Humans have survived instantaneous exposures to much higher accelerations, but that's not relevant here.)

So locals wouldn't need to be that different from us. Assuming similar biology, they'd probably be a little shorter and stockier than us, but not by orders of magnitude.


"I suspect the scale law will limit the size of any living creatures on a planet with a 2g-plus gravity even more than it does on Earth."

Keep in mind that most ecosystems don't have animals anywhere near the maximum possible that their planet can theoretically support. We know sauropods can or could live on Earth, since they did, but all we have now are the comparatively puny elephants, and even those only live in a few localized spots, while the rest of the planet makes do with even smaller critters.

(I'm ignoring aquatic creatures, since they're less affected by gravity anyway.)

In any case, small creatures can still be interesting. Of the non-primate animals on Earth today, the two I judge most likely to evolve sentience in the geologically near future (if we don't interfere) are elephants and crows, so while there's bound to be some minimum size for a sentient species, there's obviously a fair amount of leeway.

Nor would they necessarily be slow - stocky, close-to-the-ground animals like crocodiles are still good sprinters, even out of the water. You might not quite have graceful gazelle, but the less-graceful-looking locals could still be more agile than you'd give them credit for.


"If Kepler-22b is a waterworld, the sailing might be good. You'll need a lander that can float, however."

Sailing is boring if you have nowhere to go. Although now you mention it, I'm wondering what kind of weather patterns might be found on a global-ocean world.


"Arthur C. Clarke discussed "planetary chauvinism", suggesting we shouldn't overlook giant space stations as habitation options."

I think that space stations of any sort other than hollowed-out asteroids suffer from the crucial flaw of not having access to important resources, like dirt.

Also, planets have prettier scenery. Can't ignore that.


"Even we do choose to settle habitable planets, I think some people will live on spaceships and stations."

Some people, sure, but not the majority of the population.



Jollyreaper:

"We all think that buy how much space do you experience in your daily life? Not counting vacations, just home, office, the commute, a few stores. It's probably not as much as you'd think at first."

But vacations are an important part of life. There are a few locations that we visit commonly, and then a bunch of locations that we only visit rarely, possibly even once in a lifetime - but the latter are still important. Furthermore, even locations that we never visit are relevant in that they give us more choices on where to spend our vacation according to our individual tastes.

Finally, there are locations that we never personally visit, but that we are still economically dependant on via intermediaries. Farms are a rather expansive example.

Christopher Phoenix said...

Tony:

"Only to somebody that doesn't have to do it."

You have a point. Some people get claustrophobic on an island. How would they fare in an O'neil colony?

However, my concept of living in a starship or space station is influenced by SF, not the dream of O'neil colonies and a space economy.

So, here is my SF-fueled conception:

Really large spaceships and stations have large habitation sections. As in inhabitant, you will live in an environment of small rooms, curving halls, pneumatic doors, and LED lighting panels.

Pictures of stars, galaxies, and nebula are displayed wherever there is a spare screen handy to make up for the fact that being in space makes the colors of nebula and the structure of galaxies no easier to see.

Gravity is provided by spinning the ship. Some lucky astronauts in SF have gravity field generators, but so far it seems the only way to create gravity is by piling a lot of ultra-dense matter under the floorboards. Good luck launching with that weight!! If you can't spin the ship, you'll just have to put up with zero-g when your ship is not accelerating.

There is a space greenhouse, with space-plants. This is the only part of the ship where you can see lots of green growing things. If you take a fellow astronaut on a date, this is probably where the two of you will go.

Between various sections of the spaceship are large bulkheads which refuse to close when you are trying to keep the giant silicon-based alien space spiders out and then refuse to open when you become trapped on a section that the space spiders infiltrated. At a certain point, you will become thoroughly fed up with the bulkheads and blast through them with a Standish beam projector.

http://www.technovelgy.com/ct/content.asp?Bnum=696

Rifles? You mean primitive chemically fueled projectile weapons? No rifles here- astronauts carry 100Kw laser pistols and 500Kw laser rifles. Alternatively, there are particle beam guns, pulse rifles, microwave beamers, proton-beam incinerators, atomic blasters that hurl a blast of subatomic particles by detonating an atomic charge- okay, you get the idea.

You can also carry rocket guns or electromagnetic needle-guns that chip rounds off a solid block of metal and accelerate it with electromagnetic coils. One flechette may not put a space monster down, but bursts of 100 will...

Why are space monsters always bugs?

"A million bucks worth of weaponry, and I'd trade it all back for a lousy can of raid..."

http://www.youtube.com/watch?v=EP-kG4cC7P4

Some of the largest space colonies and generation ships actually replicate ground environments. However, the world is hollow and you will touch the sky if you climb the mountains.

I know that this is a bit beyond "plausible mid-future". On a plausible mid-future ship, everything is small and cramped, everyone floats, and there are no pneumatic doors, horror of horrors!!

Christopher Phoenix said...

Milo:

Interesting discussion!

"So locals wouldn't need to be that different from us. Assuming similar biology, they'd probably be a little shorter and stockier than us, but not by orders of magnitude."

I think that they would be shorter, stockier, and more muscular than we are. Imagine arm wrestling one!!

However, the likelihood that an alien species will resemble humans is probably fairly low. Intelligence doesn't need a humanoid form.

In Olaf Stapledon's Last and First Men the intelligent Venusians are shaped like swordfish, have three limbs to manipulate objects, and live off of radioactive elements decaying in their bodies like the rest of Venusian life. That doesn't stop them from having a technological civilization and destroying an Earth spacecraft with a bomb when the Humans began terraforming Venus.

I think humans will find it difficult to live on a planet with a gravitational field 2.4 times the Earth's for an extended period of time without some modification. Walking around and lifting objects would be difficult and tiring, especially for long periods of time. Miscarriages and other complications would be more common for pregnant women on a high gravity world.

At first, I'm sure a healthy human would be able to walk around without too much difficulty. Over time, though, the high gravity will take its toll.

I think that space stations of any sort other than hollowed-out asteroids suffer from the crucial flaw of not having access to important resources, like dirt.

Also, planets have prettier scenery. Can't ignore that.


The question seems to be whether the majority of humans will choose to settle on planets rather than live in O'neil style colonies. I think more people will choose to settle planets and moons.

Planets offer the resources required to build a technological civilization. Dirt, metal, volatiles, etc are all available on Mars, for instance. Planets do have prettier scenery, as well.

Space habitats are giant spacecraft, not miniature planets. People can live in a giant spacecraft, but they don't offer abundant resources and room to grow like a planet does. The spacecraft will have to mine asteroids and comets to obtain resources.

A space habitat might be a good home for a religious group or extremist political group. Millions of miles of hard vacuum separate the habitat from the rest of human society. The inhabitants can make their own rules and live in the way that they desire. The leader of a cult can literally have his own little world, as long as the Orbit Guard doesn't step in!!!

Sounds somewhat nightmarish.

When in doubt, I refer to retro SF. And retro SF says that if you don't have cities on Mars, it isn't the future. Period.

By the way, you don't have to be anonymous and sign your name in your comment. You use Name/URL- giving a URL is optional. You don't even have to give your E-mail address. : )

Anonymous said...

=Milo=



Christopher Phoenix:

"However, the likelihood that an alien species will resemble humans is probably fairly low. Intelligence doesn't need a humanoid form."

True, of course, but that applies even on worlds with the same gravity as us.


"At first, I'm sure a healthy human would be able to walk around without too much difficulty. Over time, though, the high gravity will take its toll."

You'd also be getting a lot of exercise!

Jim Baerg said...

Tony "And the interior of a tube is just not the same as a whole planet for variety and freedom."

I am aware that a cylinder a few km across isn't large enough to allow me to do a several km XC ski trip such as I did today. It will however allow more variety than a space hab that with dimensions of meters. The variable gravity in a rotating space hab is a nice bit of variety I can't get here.

BTW Christopher Phoenix: A resonably self-sufficient space habitat won't have a greenhouse section, it will mostly be one big greenhouse.

Christopher Phoenix said...

"BTW Christopher Phoenix: A resonably self-sufficient space habitat won't have a greenhouse section, it will mostly be one big greenhouse."

All the proposed O'neill colonies- Island One, Island Two, and Island Three- had separate agriculture sections. O'neill wanted to design a large space settlement that would be pleasant to live in- thus the large, airy metal-and-glass structure containing cities, forests, houses, and beaches. The big, airy cylinder was not for raising food but providing living space. Food comes from the agriculture ring.

The agriculture sections are designed for an extreme form of intensive gardening. The perpetual sunlight and lack of weather allows the settlers to raise a lot of produce in a very small space. The plants in the living sections are mostly decorative.

http://en.wikipedia.org/wiki/Island_Three

On a large spaceship, it is quite possible that there will be a greenhouse section for fresh food and the crew's mental health. However, the rest of the ship will be somewhat more utilitarian- no beaches!!

Cross country skiing in spaaaaace!!!!!

Someone who inhabits an O'niell colony will never see bad weather, let alone snow and ice. Who would freeze their colony? The pictures of O'niell colony interiors always show nice, sunny weather and people on a beach. Come to think of it, a space habitat is a good place for a nudist colony...

Interplanetary Weather Report 2097:

Sol: Solar Storm at 0300 Hours. Interplanetary rocket liners take note.

Island 3: Sunny, as always. Light rain scheduled at noon station time.

Luna: There is no atmosphere. Thus no weather.

Venus: Cloudy with acid rain. Doesn't matter, since all the colonies float above the clouds.

Mars: Planet-wide dust storms. Stay in your Mars Bases.

Jupiter: Who the heck lives on Jupiter?

Titan: Cloudy with a chance of hydrocarbon rain.

Pluto: Do you really need to ask? No atmosphere- NO WEATHER!!!!!

Thucydides said...

People building Island 3 colony structures are not limited to Gerard K. O'Neill's vision. If you have the resources and will to do such a thing, there is no reason not to have different layouts, weather or local topography designed to your taste (or if you are creating some sort of biosphere habitat; to match the flora and fauna you wish to house). Rolling fields of grain or having a cold, snowy climate are trivial compared to the scale of energy and resources to actually build such a thing.

O'Neill also studied and wrote about these designs starting in the 1970's, so many assumptions are based on 1970-80 engineering knowledge and practice; reinforcing the cylinder with steel cables, for example. Today, we might speculate about using graphine, carbon nanotubes or genetically engineered spider silk as the reinforcement material, making the structure stronger, lighter or far larger than possible with steel.

For that matter, we can speculate on a grand scale about using superstrength carbon materials to make really huge structures (see here: http://www.iase.cc/openair.htm; http://www.orionsarm.com/fm_store/SpaceRings.pdf).

In a long enough time frame, we will see people attempting these feats for a wide variety of reasons (which we may or may not find very convincing).

Jim Baerg said...

Christopher Phoenix Re: separate agriculture section in Space Habs.

Just to make sure we are not in violent agreement ;)
You want the plants growing & the people breathing in the same enclosure so no complicated plumbing is needed to get the CO2 from people to plants & O2 from plants to people.

The sort of thing I'm thinking of is an O'Neill cylinder or Stanford Torus with a layer of residential appartments, offices, light manufacturing etc. on the bottom/outside, & above that a layer of rooftop garden/park/orchard/farmland exposed to sunlight to produce food & oxygen. I doubt the layer of garden would support more than the population of 1 layer of residences below it.

The lower layer might be something like the 'utilitarian' sections you were talking about, but I didn't get the impression you were talking about anything similar to my idea.

Sean said...

I think an O'Neil cylinder would probably be the vanity project of a post-scarcity civilization of transhuman demigods. There's just no real justification for the construction of that sort of habitat, not whilst we have a perfectly good moon orbiting our homeworld. But even that's a bit of a dream, I think its more likely we'll see people colonize Antarctica or the oceans for that matter.

Tony said...

O'Neill was an East Coaster who spent most of his life either in big cities or college towns like Princeton, NJ and Ithaca, NY. His idea of the great outdoors had more in common with a garden than with the wilderness us Southwesterners are used to. His plan to segregate agriculture from the living area was in line with this. The farm was someplace bad or poor kids were sent to work for the summer, not someplace civilized people would want to inhabit. It's pretty obvious from his writings that things like four-wheeling, shooting, camping, etc. just didn't enter into his plans. In High Frontier his consideration of outdoor activities had to do with swimming, diving and human-powered flight in low spin gravity regions. For the higher spin gravity sections, highly organized outdoor sports like baseball were considered from the perspective of what coriolis force would do to the flight of a batted or thrown ball. The man lived in a nice, safe suburban world, and he figured everybody else would want that.

Thucydides said...

Given the explosion of suburbs and exurban "pods" since the 1970's, I suspect a lot of people would like to live in a nice, safe, suburban neighbourhood. If the neighbourhood happens to be located in L4 or L5, a great many people would see that as a feature, not a bug. Camping trips and 4X4 expeditions would be on the Moon, rather than the Grand Canyon.

Many of O'Neill's speculations and ideas make sense from engineering and economic perspectives; a colony structure in space can be optimized for gravity, day/night cycles and in many other ways, while a planetary colony will be constrained by the conditions of the planet. If it turns out that living in 1/6 "G" is bad for you, it is a bit difficult to adjust the gravity of the Moon to compensate...

Common systems and modular construction can be applied to free flying colonies almost anywhere in the solar system, mirrors and radiators would have to be scaled for different orbits around the sun, but the basic habitat structures would remain. Planetary colonies on the other hand would be unique constructs for each location in space, no economies of scale to be had there.

Will people want to live in Island 3 colonies? Sure, lots of people would. Is there an economic case for building Island 3's? Not at the present time. Past the PMF, we will probably see a wide variety of ideals for living, including planetary colonies and free flying space structures, and probably ideas we would have difficulty imagining today.

Nick P. said...

So...I guess the takeaway from this is that some people will choose to live in habitats and some people will choose to live on planets for a wide number of reasons.

You know, like how right now people choose to live in cities or the country due to any number of factors.

Tony said...

Nick P.:

"So...I guess the takeaway from this is that some people will choose to live in habitats and some people will choose to live on planets for a wide number of reasons.

You know, like how right now people choose to live in cities or the country due to any number of factors."


Perhaps superficially. But O'Neill's vision was a visions for the future of the vast majority of the human race -- dull, conformist, canned lives. Certainly progress should mean more than that.

Rick said...

Welcome to a couple of new commenters!

I tend to think that any large space habs will be modular structures, not single megastructures, for a couple of reasons. One is safety - megastructures are an invitation to mega failure.

But even more fundamentally, that is just not how cities generally develop. They grow by accretion, and I would expect cities in space to grow the same way.

(The overall likelihood of large scale space settlement in even the semi-demi foreseeable future is a different matter. I don't think this is very likely, unless shirtsleeves planets turn out to be readily accessible. And do they quite qualify as space settlements?)

But even a much more modest level of space development raises questions about just how well humans can live in a can. (Including how big of a can it takes.)

I suspect that - in spite of stereotypes - Eastern (US) cities may have more connection with their rural surroundings than Western ones do. After all, cities in the US Southwest are often surrounded by nearly uninhabited desert - no sportsmen's paradise - rather than farmland, forests, or whatever.

But getting back to the main point, even Manhattan is not an enclosed can, and you don't need a space suit to go outside it. Whether a broad range of humans would be comfortable in even a city-sized can is an unanswered question.

The only way to answer it may be by test - a very expensive test if you build the can, and it turns out to be not quite habitable.

Anonymous said...

=Milo=



Thucydides:

"Planetary colonies on the other hand would be unique constructs for each location in space,"

Which I see as a feature, at least from a romantic perspective. It forces each of them to be a creative, interesting location, rather than just carbon copies of what we're used to.

Why would you bother vacationing to a tropical island resort if the tropical island has a climate identical to where you live?



Rick:

"Whether a broad range of humans would be comfortable in even a city-sized can is an unanswered question."

I'll reiterate what I said previously about rare occurences still being important.

While many people would be comfortable staying in a single city 99% of the time, their happiness will still depend significantly on how easily they can visit the outside world the remaining 1% of the time.

Tony said...

Rick:

"I suspect that - in spite of stereotypes - Eastern (US) cities may have more connection with their rural surroundings than Western ones do. After all, cities in the US Southwest are often surrounded by nearly uninhabited desert - no sportsmen's paradise - rather than farmland, forests, or whatever."

I think that it's more accurate to say that most East Coast cities are surrounded by intensively gardened hinterlands that used to be wilderness. And the whole point of wilderness as an attraction is that it's "nearly uninhabitted". Not that the subalpine woods and montane shrublands here in Southern Utah (just two hours drive from the prototypical desert city of Las Vegas) are exactly a desert region.

"But getting back to the main point, even Manhattan is not an enclosed can, and you don't need a space suit to go outside it. Whether a broad range of humans would be comfortable in even a city-sized can is an unanswered question."

I think that's why O'Neill tried to imagine relatively low population density garden habitats. It just never seems to have occurred to him that not everybody -- and I think not most people, given the choice -- want to live in gardens.

Christopher Phoenix said...

Jim Baerg:

"The lower layer might be something like the 'utilitarian' sections you were talking about, but I didn't get the impression you were talking about anything similar to my idea."

No, I wasn't talking about anything similar to your idea. The spaceship I was describing is not a space city with residential apartments. It is a spaceship designed to travel vast distances across space and support a crew of astronauts. Maybe they are going to visit Kepler-22b, if they have a suitable hyperdrive. So we aren't in violent disagreement, since we aren't discussing the same kind of space structure.

Thus references to astronauts, space monsters (what SF story lacks space monsters?), and the inordinate amount of weaponry that is included in my spaceship's armory. After all, the Terran Space Force supported and supplied some of the supplies for this flight...

Such a ship would have a large habitation section, hydroponics, artificial gravity, and a much more utilitarian design than O'neill's Suburban Housing Developments in Spaaaace!!!!!!! There will also be a propulsion section, landing craft, and carefully quarantined laboratory sections. There might be a hibernaculum if the voyage will take years.

You're right that you want the plants near the people in a CELSS (Controlled Ecological Life Support System). Maybe the hydroponics gardens and living quarters on my exploration starship can be interspersed.

I think that a spaceship's CELSS should not be too fancy. I've read about Biosphere 2, and I think that it was much too fancy too succeed. Who needs a coral reef? Why are we raising pigs? Who let ants into the habitat?

A serious spacecraft only needs to be able to revitalize air and produce food and other consumables. No coral reefs, rainforest environments, or tigers are needed.

Future spaceships will probably contain greenhouses for CELSS and food supply, and Japanese astronauts insist on a space fish farm for space sushi, but remember the KISS principle- keep it simple, stupid!!

Tanks of algae can recycle air. May not be as pretty as a rainforest, but it is certainly simpler. Fancy orbital suburban neighborhoods may offer botanical gardens, but spaceships will have to be more practical.

Large lunar and planetary colonies or large orbiting habitats will probably have features similar to what you describe- large gardens, farmland, etc.- but exploration ships or utilitarian space stations won't. Living in space is generally not a country-ish, outdoorsy thing to do, unless your idea of outdoor sports is driving a space buggy over the Martian sand dunes.

Although I must admit that a glass dome containing a rainforest with Jupiter rising in the background will look extremely neat.

I insist that my spaceship bring along means to create peanut butter. Humanity cannot live without peanut butter. So add a peanut garden alongside the sushi fish farm.

Christopher Phoenix said...

Rick:

Thanks for the welcome!! Few blogs are quite as, well, welcoming as this one!!

"But even more fundamentally, that is just not how cities generally develop. They grow by accretion, and I would expect cities in space to grow the same way.

(The overall likelihood of large scale space settlement in even the semi-demi foreseeable future is a different matter. I don't think this is very likely, unless shirtsleeves planets turn out to be readily accessible. And do they quite qualify as space settlements?)"


What about smaller-scale efforts? A group of freedom-loving individuals settle on the moon or Mars. Perhaps individual families fly to Mars in small spacecraft. A group of these spacecraft can be repurposed into a small Martian settlement. A small but steady incoming stream of colonists and children being born to the settlers will eventually lead to a larger Martian population.

Personally, I would settle on Mars. Mars has all the resources required by human civilization, unlike a space habitat floating in the middle of nowhere. Crazy, probably, but I'd take my chances living in a grounded spacecraft settled on the soil of a desolate Martian desert rather than living a dull, conformist, canned life in a heavily regulated space habitat.

As for shirtsleeve planets- if any are available, I'll be first in line to claim them.

Tony:

"Perhaps superficially. But O'Neill's vision was a visions for the future of the vast majority of the human race -- dull, conformist, canned lives. Certainly progress should mean more than that."

I agree. Some people might like living canned lives, but many won't. That is part of the appeal of space- it is a vast, endless, unexplored wilderness. Don't get me wrong- I don't think space is a libertarian wonderland- but millions of miles of hard vacuum does tend to put a gap between you and undesired policies and lifestyles back home.

I think it would be better to start a new space settlement piece by piece. The spacecraft that the new settlers arrive in can be repurposed as their first homes. The settlers then began utilizing local materials to build larger structures.

Who wants to go to Mars? Lets see- aging scientists who want to spend the latter years of their life studying the Martian environment and enjoying the 1/3 g gravity field, students who dream of applying their skills to surviving on a new world (trust me, there is no lack of idealistic young would-be-space-cadets), individuals who feel stifled by the conformist modern age, and so on...

Would these people want to live a garden-variety suburban lifestyle in a glass tube? No. Gerard O. Neill underestimated the kind of people who want to live in space.

Life on Mars will be much more rugged and dangerous than life in a space station or a space habitat. I've seen references to hiking over Martian sand dunes, climbing Martian mountains, and rappelling down Martian cliffs. I imagine scientists going on Martian camping trips to look for fossils or colonists racing Martian dune buggies. Not quite Gerard's vision of life in space.

Rick said...

I imagine scientists going on Martian camping trips to look for fossils or colonists racing Martian dune buggies. Not quite Gerard's vision of life in space.

O'Neill's vision was, in some ways, Ultimate Suburbia.

But perhaps more importantly it was a creation of the era just after we learned - via (robotic) space exploration - just how far from being habitable the rest of the Solar System really is.

Back in the golden age of SF, large scale habitation off Earth was associated with habitable or terraformed planets. 'Domed colonies' - the planet-surface counterpart of O'Neill cans - were only a small part of the golden age space future.

I will be discussing this at greater length as soon as I write it!

Tony said...

Christopher Phoenix:

"Who wants to go to Mars? Lets see- aging scientists who want to spend the latter years of their life studying the Martian environment and enjoying the 1/3 g gravity field, students who dream of applying their skills to surviving on a new world (trust me, there is no lack of idealistic young would-be-space-cadets), individuals who feel stifled by the conformist modern age, and so on..."

The problem is that idealists and adventurers are not going to be qualified to go in the first place. The few that are talented enough and manage to achieve the educational and technical qualifications are going to turn into the kind of people that astronauts and cosmonauts have always been: good explorers, but people who definitely have jobs, families, lives in general worth coming home to.

Any that still want to go spend their lives in space or on Mars would fall into the category of fanatics. If I'm the government bankrolling this, I'd sooner eliminate the fanatics than almost any other class of candidate. They can't be counted on to advance organizational objectives above their own.

Sean said...

Speaking of colonization: http://www.kurzweilai.net/ill-put-millions-of-people-on-mars-says-elon-musk

Elon Musk once had my respect as an innovator, now I think he's just as deluded as Robert Zubrin.

jollyreaper said...

Is he just crazy or just crazy enough to be onto something? I'd say crazy but I've been wrong before.

Tony said...

Sean:

"Speaking of colonization: http://www.kurzweilai.net/ill-put-millions-of-people-on-mars-says-elon-musk

Elon Musk once had my respect as an innovator, now I think he's just as deluded as Robert Zubrin."


jollyreaper:

"Is he just crazy or just crazy enough to be onto something? I'd say crazy but I've been wrong before."

Wey-ull...the actual statement was that he'd put ten thousand on Mars, and that ultimately millions might move there. I have a couple of things to say:

1. The fact that Kurzweil picked up on this is an informative datum in and of itself. It means that it's considered news by people who have a very shaky relationship with reality.

2. It's the kind of thing that visionary industrialists always say, but that few of them ever deliver on. So, move on, there's nothing to see here...

jollyreaper said...

The fact that Kurzweil picked up on this is an informative datum in and of itself. It means that it's considered news by people who have a very shaky relationship with reality.

Pardon me sir or madam but has anybody ever witnessed to you about the Singularity? You can develop a close and personal relationship with your very own techno-rapture. Salvation for just pennies a day! Immortality guaranteed or double your money back!

Sean said...

I'd have posted the complete article from New Scientist, but I don't have a subscription sadly. The techno-prophets at Kurzweil had to do.

Thucydides said...

Since we have moved from giant planets to giant structures in space, a few observations are in order here:

1. Giant structures in space are required for many reasons, including the need for radiation shielding and to provide enough inertia to overcome the movement of people and equipment within the structure. Unbalanced structures in space=bad things happening.

2. Biosphere 2 was on to something (but obviously there needs to be far more experimentation). Ecologies need to be as rich and diversified as possible to ensure there are no catastrophic "crash" events. A tub of algae may be very efficient at converting waste and producing O2, until a mutant strain of e coli shows up and starts eating it. The Irish discovered the dangers of monoculture in the 180's, a lesson we should take to heart today.

3. Bespoke structures for different planetary environments will be nightmarish rather than romantic. No body of experience would be able to be carried totally over from one environment to the other; you will always be on the wrong end of a dangerous and expensive learning curve. Island habitats are essentially giant thermos bottles with solar mirrors and heat radiators matched to the location in space attached. What works on an Island colony in L5 works in the Jovian trailing Trojans as well.

4. O'Neill viewed the Island colonies as essentially the homes for the workers who were busy building lunar mines and solar powersats. These are not "pioneering" people as we might think of them but rather industrial workers who want a nice home with beers and barbeques to relax in. O'Neill didn't talk about the darker side of industrial neighbourhoods (probably because he never lived in one), but various authors have written dystopias with seedy L5 colonies full of bars, strip joints and so on (Allen Steele anyone?).

By the time humans (or post humans) reach the stars to study giant planets up close, there will be centuries or millenia of experience in living and working on space to draw from.

Anonymous said...

=Milo=



Thucydides:

"Ecologies need to be as rich and diversified as possible to ensure there are no catastrophic "crash" events."

This depends on how long they need to be autonomous. If your ecology needs to be able to last for decades in isolation, then yes. If you just need to hold out for a few months between restocks, not so much.

Tony said...

Re: Thucydides

One has to ask one critical question: what project or industry in space is so large and profitable that it justifies megastructures -- and all of the energy and resources that would go into them -- as mere residential districts. I can see rotating cans roughly the size of supertankers, with many internal decks. But O'Neill Island X colonies? I just can't see a motivation.

I give O'Neill credit for grandiose thinking, but not for practicality.

Thucydides said...

O'Neill's starting point (I think) was a seminar he held in the early to mid 1970's asking "is a planet the best place for a civilization?"

If we are thinking of a work camp like the ones springing up by the Alberta Oil Sands or North Dakota's Bakken fields, then a supetanker sized "can" will do nicely. If we are looking at a place for civilization (or even Civilization), then you need lots of room!

The economics and practical arguments for doing so (or not) have been pretty much wrestled to the ground here.

Christopher Phoenix said...

Thucydides:

"Ecologies need to be as rich and diversified as possible to ensure there are no catastrophic "crash" events. A tub of algae may be very efficient at converting waste and producing O2, until a mutant strain of e coli shows up and starts eating it."

Include many tubs of algae with different strains of algae. You still don't need coral reefs, jungles, or man-eating tigers in your spaceship. We are running a spacecraft, not a communal back-to-nature pig farm.

Come to think of it, in James Blish's Cities in Flight, New York City's food and oxygen are produced by tanks of algae. While the city is flying near a supernova, enhanced radiation levels mutate the algae, causing the city's food supplies to become endangered.

Maybe someday we will have Silent Running style spaceships with an entire deck devoted to a small rainforest, but it doesn't seem very necessary for most spacecraft or space stations.

The exact details of the life support system will depend on the purpose of the spaceship. A rocket ship that goes on trips around our solar system only needs to hold out for a few months between resupplies. A self-sustaining space city or planetary colony designed for long term habitation by a large number of people needs robust life support, plenty of space, and maybe a rainforest environment. A science-fictional exploration starship with a hyperdrive needs a robust and compact life support system that can hold out for years if necessary.

Tony said...

Thucydides:

"If we are looking at a place for civilization..., then you need lots of room!"

Please stop with the exclamation points. Exhortative rhetoric is not convincing.

And you won't need much room at all if you kill everybody off by oversubscribing your resources to making luxury living space at the expense of getting anything useful done. I really don't think you comprehend just how resource and energy intensive these megastrtuctures would be.

Also, you upstream assertion that, "What works on an Island colony in L5 works in the Jovian trailing Trojans as well," is demonstrably not factual. If you're relying on solar energy, you need to devote a larger fraction of your resources to collection, rectification, and distribution than you do if you're 5 times closer to the sun with 25 times the insolation.

Christopher Phoenix said...

Tony:

"One has to ask one critical question: what project or industry in space is so large and profitable that it justifies megastructures -- and all of the energy and resources that would go into them -- as mere residential districts. I can see rotating cans roughly the size of supertankers, with many internal decks. But O'Neill Island X colonies? I just can't see a motivation."

Yeah- these residential megastructures sound like something out of Star Wars. Speaking of Star Wars, the Executor-class Star Dreadnought is 19km long and can accelerate a 1230g. This is obviously far, far beyond "plausible midfuture" (and I am ignoring various scientific inconsistencies between the world of Star Wars and our own).

Not to mention that building huge spaceships is not just a matter of finding enough raw materials. Size matters because of gravity and acceleration. If you are building an immobile space habitat in microgravity, size doesn't matter. If you are building a spaceship, size matters a lot. As a structure grows larger, mass increases faster than load-bearing area. If you increase the scale of a ship by 10, the mass will become 1000 times greater but it will get only 100 times stronger.

When it accelerates, the stress can tear a huge structure like the Executor apart unless it is made of extraordinarily strong materials. This is why Galileo knew that there is a "proper size" for everything. You can't scale something up without radically altering the design, and if something gets too large, it becomes infeasible regardless of design. This is the reason that Dyson spheres and ringworlds need super-materials. Kind of puts space opera settings in perspective.

http://www.stardestroyer.net/Empire/Science/Size.html

On the oil tanker sized spinning habitats- don't forget that if the radius of a spinning habitat is too small, the inhabitants will experience motion sickness. Some people might adapt, but on the whole most people won't be comfortable. Something to keep in mind.

Damien Sullivan said...

Lots of insults of the majority of the human race that's urban, I see.

"I'd take my chances living in a grounded spacecraft settled on the soil of a desolate Martian desert rather than living a dull, conformist, canned life in a heavily regulated space habitat."

Most likely the Martians would be leading dull conformist canned lives in heavily regulated Martian habitats, since Mars outside is about as deadly as space outside. Occasionally they could leave the 1/3 g can to waddle in the 1/3 g outside in their spacesuits and admire the alien view, instead of leaving their 1 g can to float in zero gee in their spacesuits and admire the space view.

Me, I'd rather live in space Chinatown than space Billings. And some modern Americans may think life without an SUV and wilderness is unthinkable, but how often did a Chinatown or Jewish urban immigrant see the Big Outdoors?

Here's a prediction: if space is ever colonized, it will be by people who aren't too picky about the conditions.

Thucydides said...

Multiple tubs of different strains of algae is an ecosystem (although still a fairly limited one). The example from Cities in Flight shows that there should be many different and independent ecological "loops" to insulate the system from external events and crashes.

The core of the "Island" colony structure can remain the same regardless of where you are in the solar system, but the mirror and radiators will be of the appropriate size, the ones in the Jovian orbit will be much larger than the ones in Earth orbit. If I wasn't clear about that earlier,then I apologize.

Rick said...

various authors have written dystopias with seedy L5 colonies full of bars, strip joints and so on

Colonies without any of those things strike me as more dystopian.

Anonymous said...

So, where would you like to spend shore leave? Detroit or Las Vagas?

Ferrell

Thucydides said...
This comment has been removed by the author.
Thucydides said...

Slip of the finger.

Interesting article here:

http://www.washingtonpost.com/opinions/are-we-alone-in-the-universe/2011/12/29/gIQA2wSOPP_story.html?wprss=rss_opinions

Tony said...

Thucydides:

"The core of the "Island" colony structure can remain the same regardless of where you are in the solar system, but the mirror and radiators will be of the appropriate size, the ones in the Jovian orbit will be much larger than the ones in Earth orbit. If I wasn't clear about that earlier,then I apologize."

What I don't think you're too clear on is how different costs of energy affect your habitat economics (and the economics of any associated businesses). The sunlight isn't free. You have to invest in collection, rectification, and distribution systems. The bigger they have to be for a given amount of power at the outlet, the more expensive your power is. More expensive power doesn't work "as well" as less expensive power, not at the overall system level.

Thucydides said...

The economic impact would be that you would either have to invest more for the power and light, or build fewer colonies for the same amount of money. The main point that I am trying to make is the colonies themselves are going to be well understood modular structures with well known building templates.

Structures built on the surfaces of planets and moons will not have the same advantages, since everything from gravity to temperature control to dealing with weather will be unique to that environment, and will have to be learned anew with each new planet or moon that you reach.

Tony said...

Thucydides:

"The economic impact would be that you would either have to invest more for the power and light, or build fewer colonies for the same amount of money. The main point that I am trying to make is the colonies themselves are going to be well understood modular structures with well known building templates.

Structures built on the surfaces of planets and moons will not have the same advantages, since everything from gravity to temperature control to dealing with weather will be unique to that environment, and will have to be learned anew with each new planet or moon that you reach."


Sorry, but here on the Earth we have rules of thumb -- and quite often well developed procedures -- for dealing with widely varying environmental conditions, including pressure, temperature, insolation, and weather. I see no reason to believe it would be different on any other planet.

Thucydides said...

Rules of thumb developed for Mars will not be very applicable on Titan, and your experience in building there will not help you throw up structures on the moons of Uranus.

Tony said...

Thucydides:

"Rules of thumb developed for Mars will not be very applicable on Titan, and your experience in building there will not help you throw up structures on the moons of Uranus."

Why would anybody build large communities in those places? In the Solar System I think Earth and Mars are pretty much it for large scale settlement.

Thucydides said...

Why do people build anywhere? There are lots of places even in Canada and the United States which don't seem likely as places to settle and live,

In the far future, people might choose to settle on Mars as being the easiest place, but other people will be attracted to other places seeking opportunities or adventure. Once we can get to Mars, going anywhere else will be relatively easy.

Tony said...

Thucydides:

"Why do people build anywhere? There are lots of places even in Canada and the United States which don't seem likely as places to settle and live,

In the far future, people might choose to settle on Mars as being the easiest place, but other people will be attracted to other places seeking opportunities or adventure. Once we can get to Mars, going anywhere else will be relatively easy."


Mineral extraction communities are hardly what I'd call "settling". They all become ghost towns as soon as the hole dries up.

But that's not what I was talking about. The kinds of rules of thumb I was referring to have to do with so much insulation for so much internal to external heat differential, the construction of pressure-tight structures, the provision of power/water/light, etc. Those are pretty universal and work almost anywhere you go.