Olduvai Cliff theory

[Rococo Modem Basilisk]

Bah. If the earth is heading downhill, it's good to have something off the earth as a plan 'b'. I don't suggest trying to terraform a planet that is very much unlike earth -- terraforming mars would take a very long time, and is the easiest to terraform as-is. Space stations are designed for human habitation, and can be built to simulate gravity along the outer edge. Granted, we as humans will have issues with low gravity, which is why I figure it'd be of the utmost importance to try to get it as close to 1g as possible without the whole thing ripping apart or moving out of the appropriate orbit.

Given sunlight, artificial gravity, water, and an air supply, plants can be grown. I have no idea what the ratio is between humans and plants in terms of how much vegetation there needs to be in order to convert the CO2 of one human back into oxygen, but given that current space stations don't have many plants and probably depend very much on auxiliary oxygen-nitrogen tanks, plants will probably ease the load and over time a bigger infrastructure can be built that will allow closer to 1-to-1 correlation between CO2-producing and CO2-breathing organisms. The fact that plants are used to soaking up light from above and in the system described light would be coming from below could be a problem, though not an unsolvable one. Maybe mirrors can be used to redirect light from the center of a wheel-type space station, or maybe it might be useful to have the outer rim be transparent or translucent and keep tanks of photosynthesizing algae there.

I don't claim to know anything about space travel. In fact, it's one of the things I have unnaturally little interest in. But if we must go out into space (or if we have the ability and people are willing) I think it's probably an all-around better idea to start with space stations rather than with terraforming planets. Even if we made a sealed environment on another planet, there's no way we could change the gravity level, so a lot of the health problems involved in living in lower gravity will be unavoidable except by some proactive mechanism that to my knowledge has not yet been discovered. At the very least, in a space station that is wheel-shaped, you can in theory speed the thing up.

[nurbldoff]

Without reading the actual papers, the main problem with the theory (disregarding the fact that its predictions haven't turned out to be too accurate) seems to be that it assumes that energy consumption per capita will not decrease. If it did, a shrinking energy production might not be a problem. Of course, energy consumption seems to be increasing monotonically, so that's a big maybe. In any case, these broad, long term predictions are probably mostly popular because they're hard to disprove immediately, and when they turn out to be false, enough people have already bought the books.

I'm all for space stations --- as someone (RAW?) said, why climb all the way out of a gravity well just to get trapped in another? Seriously though, terraforming e.g. mars won't give us another earth, since the incoming sunlight is much weaker. Basically wherever we go, we're not likely to find a planet that exactly matches earths climate, which probably means pretty harsh conditions anyway. On the other hand, by that time it might be trivial for us to genetically alter ourselves to fit almost any environment, including space. But now we're really getting into the long term prediction game...

The question could become relevant sooner than we think, considering that we might already be unterraforming earth.

[Bebek Sincap Ratatosk]

Without reading the actual papers, the main problem with the theory (disregarding the fact that its predictions haven't turned out to be too accurate) seems to be that it assumes that energy consumption per capita will not decrease. If it did, a shrinking energy production might not be a problem. Of course, energy consumption seems to be increasing monotonically, so that's a big maybe. In any case, these broad, long term predictions are probably mostly popular because they're hard to disprove immediately, and when they turn out to be false, enough people have already bought the books.

I'm all for space stations --- as someone (RAW?) said, why climb all the way out of a gravity well just to get trapped in another? Seriously though, terraforming e.g. mars won't give us another earth, since the incoming sunlight is much weaker. Basically wherever we go, we're not likely to find a planet that exactly matches earths climate, which probably means pretty harsh conditions anyway. On the other hand, by that time it might be trivial for us to genetically alter ourselves to fit almost any environment, including space. But now we're really getting into the long term prediction game...

The question could become relevant sooner than we think, considering that we might already be unterraforming earth.

If we have the technology to terraform Mars... then surely we'll have the technology to fix Earth. conditions in space or on Mars will probably be worse than conditions on Earth... I think.

[Triple Zero]

Well maybe, but Mars has the advantage that it doesnt have all these people living on it, so if you make a mistake the first time around, or if terraforming turns out to be a rough ride, better to do it with an uninhabited planet, I'd say.

also, how's that coming along btw? last thing I heard about terraforming Mars was that, even if we managed, the oxygen would slowly evaporate into space anyway, or something.

[Cainad (dec.)]

Well maybe, but Mars has the advantage that it doesnt have all these people living on it, so if you make a mistake the first time around, or if terraforming turns out to be a rough ride, better to do it with an uninhabited planet, I'd say.

also, how's that coming along btw? last thing I heard about terraforming Mars was that, even if we managed, the oxygen would slowly evaporate into space anyway, or something.

Sounds plausible. Nitrogen and oxygen are both lighter gases than CO2. Even if we replaced the atmosphere with a nitrogen-oxygen mix, it wouldn't have any more pressure than it already does.

Now this is bugging me, so I'm going to do some "research"...

Wikipedia sez that Mars has about 15% of Earth's volume and 11% of Earth's mass, and that it also lacks a magnetosphere. I don't think there's any hope of covering the planet with a breathable atmosphere. We'd probably have to live in biodomes or something.

[Requia ☣]

Earth isn't actually big enough to hold its atmosphere either.  What makes mars's so thin is the lack of volcanic activity.  No volcanoes means no new gasses bubbling up from the core, whats lost doesn't get replaced.

[Bebek Sincap Ratatosk]

We'd probably have to live in biodomes or something.

Global Warming or stuck in a BioDome with Pauley Shore...

I'll grow gills, thanks.

[Cainad (dec.)]

Earth isn't actually big enough to hold its atmosphere either.  What makes mars's so thin is the lack of volcanic activity.  No volcanoes means no new gasses bubbling up from the core, whats lost doesn't get replaced.

That's news to me. Is there a name for this effect or something that I could look up?

[Requia ☣]

Not that I'm aware of.  I only went over this tangentially in thermodynamics (one of the assignments was figuring out the rate at which the atmosphere is evaporating).

[Doktor Howl]

muhaha

[Elder Iptuous]

Fortuna will provide, heathen!
your dire predictions have always failed in the past, and therefore will always fail in the future!

[Prelate Diogenes Shandor]

...we're not likely to find a planet that exactly matches earth's climate[/u]...

Which one?

[Kai]

Humans will survive. We're too good at fucking and keeping warm to go extinct due to a population crash. We can survive in any climate, find food in almost any habitat, cultivate our own food, create medicines to eliminate diseases, and develop tools to take on just about any problem.

However. A whole bunch of people are going to bite the dust in the process. Assuming it happens. Peak oil certainly has, so unless we suddenly convert to sun powered (wind and solar), gravity powered (hydroelectric and tidal) and geothermal, it's pretty clear our industrial society will collapse to a mere shadow of it's former self. Our entire transportation system responsible for the success of the last 100 years is based around the products of petroleum refining, not just gasoline, but all the other organic chemicals that are used to make rubbers, asphalt and plastics.

[Bebek Sincap Ratatosk]

Humans will survive. We're too good at fucking and keeping warm to go extinct due to a population crash. We can survive in any climate, find food in almost any habitat, cultivate our own food, create medicines to eliminate diseases, and develop tools to take on just about any problem.

However. A whole bunch of people are going to bite the dust in the process. Assuming it happens. Peak oil certainly has, so unless we suddenly convert to sun powered (wind and solar), gravity powered (hydroelectric and tidal) and geothermal, it's pretty clear our industrial society will collapse to a mere shadow of it's former self. Our entire transportation system responsible for the success of the last 100 years is based around the products of petroleum refining, not just gasoline, but all the other organic chemicals that are used to make rubbers, asphalt and plastics.

IAWTC!