Practical for a civilian to build a space suit?

[CCWilson]

I'd be interested to see some numbers on how cold the Earth would get and how long it would take to cool. The oceans are a massive heat sink, without the sun they'll freeze eventually but how long I wonder?

I've been trying to figure that one out myself. Onomatomanic did have an estimate but I've had conflicting opinions on this. My current guess is that it would get cold enough - below -185 centigrade - for oxygen and nitrogen to liquify after about a year. I suspect the surface of the oceans would freeze fairly early but liquid water might remain at the bottom permanently. But I'm doing a lot of guesswork here, and if anyone has a suggestion of an expert in any of these fields - biospherics, terraforming, climatology, astrophysics - who might be willing to talk with me, I'd be deeply appreciative. The gurus I've contacted so far haven't jumped at the opportunity.

 

[Ryan_m_b]

I've been trying to figure that one out myself. Onomatomanic did have an estimate but I've had conflicting opinions on this. My current guess is that it would get cold enough - below -185 centigrade - for oxygen and nitrogen to liquify after about a year.

I think pressure has to be taken into account as well. As some of the atmosphere freezes the rest will have a lower freezing temperature.

I suspect the surface of the oceans would freeze fairly early but liquid water might remain at the bottom permanently. But I'm doing a lot of guesswork here, and if anyone has a suggestion of an expert in any of these fields - biospherics, terraforming, climatology, astrophysics - who might be willing to talk with me, I'd be deeply appreciative. The gurus I've contacted so far haven't jumped at the opportunity.

There are no experts on terraforming and closed biospheres we know very little about (the few experiments done were failures). You're not going to find an expert in your specific field but the members of this site do have great knowledge in a wide variety of areas and IMO they've done a pretty good job so far.

 

[CCWilson]

Why risk earthquake exactly? Why not use nuclear? Or space based solar power beamed from closer to the Sun?

Nuclear and fossil fuel power would require constant replenishment of fuel and a lot more maintenance than geothermal, which requires no fuel. Clearly geothermal is the best long term option. If you had no geothermal capacity, you'd have to rely on nuclear and fossil fuels, but upkeeping those would be a massive project. Nuclear plants have lifespans of under 50 years, by the way.

The sun would quickly become a distant memory, the stuff of legend. I can't imagine that there's any technology that would allow you to use it for power.

 

[onomatomanic]

Onomatomanic did have an estimate but I've had conflicting opinions on this.

How different was the other estimate? I'd like to know for my own worldbuilding.

 

[Ryan_m_b]

Nuclear and fossil fuel power would require constant replenishment of fuel and a lot more maintenance than geothermal, which requires no fuel. Clearly geothermal is the best long term option. If you had no geothermal capacity, you'd have to rely on nuclear and fossil fuels, but upkeeping those would be a massive project. Nuclear plants have lifespans of under 50 years, by the way.

You've just invented and built multiple entirely self sufficient, closed ecosystem cities underground and you're worried about upkeep of a few reactors? Also IIRC there is thousands of years worth of fuel for nuclear reactors on Earth. More than enough to last and eventually perhaps fusion will take over. This seems much better than trying to go the geothermal route which has the dangers of an earthquake (if it disrupts your ecosystem or the geothermal plants you've got no time to rebuild before you die).

The sun would quickly become a distant memory, the stuff of legend. I can't imagine that there's any technology that would allow you to use it for power.

Out of curiosity have you worked out if it is possible/likely for the Earth just to wander off into interstellar space? I have a suspicion that an event of that much energy would devastate Earth even more. It seems more likely that Earth's orbit would become quite eccentric before leaving. I'm not sure of that though. The escape velocity for the solar system from Earth orbit is something like 40kmps, whatever it is that disturbs Earth's orbit has to impart that in the right direction (and it's still going to take many years to get anywhere).

As for technology of course there is. Look up proposals for space based solar power and beamed interstellar transport. Once the cities are up and running production could switch to nuclear rockets (no atmosphere to worry about contaminating) for delivery of solar arrays with highly focused masers into orbit around the sun. Perhaps at some point machines could be sent to asteroids to mine and refine resources to manufacture more arrays. The idea being that these arrays beam the energy to Earth.

EDIT: I mentioned earlier in thread a short story that might help but I got the name wrong. It's called Minla's Flowers by Alastair Reynolds (though it's only available in anthologies). I read it again today thanks to this thread and whilst it doesn't deal with a lot of detail it is very good at giving an insight into what a culture that has decades left will look like and what challenges they will face. Despite being given detailed, step-by-step plans of how to develop their technology and industry by a traveller from a more advanced civilisation they still find themselves set back by problems getting resources, war with those who don't want to help or want to try different options (and are hoarding resources in the mean time) etc etc.

 

[Evo]

The only effect of losing the moon (which isn't a sure thing; it could also crash into the Earth or have its orbit changed) is that the seas would be calmer.

Not according to this.

If you would take away the Moon suddenly, it would change the global altitude of the ocean. Right now there is a distortion which is elongated around the equator, so if we didn’t have this effect, suddenly a lot of water would be redistributed toward the polar regions

http://www.astrobio.net/index.php?option=com_retrospection&task=detail&id=2507

 

[Evo]

The underground cities would be concentrated where existing geothermal plants are - and the biggest complex anywhere is in the Geysers area north of San Francisco, so a number of cities would be built there. It's an unavoidable fact that the places best suited for geothermal development are where the tectonic plates come together and the magma is closest to the surface, so there's increased danger of earthquakes, but energy needs override everything for long term survival, and earthquakes aren't that common at anyone site, really.

You need to take the type of geology into consideration, those areas might not be stable enough to allow an "underground' city" to be possible. You don't want to start digging and have the thing cave in because it can't support it.

I don't see water needs as a major stumbling block. As long as most of the water is recycled, which would be relatively easy in a sealed chamber - where's it going to go? - the need for additional water wouldn't be too great.

Room needed for storage? Room for the water recycling plants?

Populations would have to be controlled, as well as for agriculture and animals. The amount of artificial light needed would be enormous.

All of the technology means that you will need to be selective about the people that can live in your "cities", you will need people that can handle the scientific, as well as engineering, construction, maintenance, etc... Perhaps a lottery for the few slots that may be left over.

Or you could handwave it all away. On Star trek TNG, they had small communities in biodomes, etc... of course placing events way into the future makes it easier to get away with a lot.

 

[sshai45]

As for technology of course there is. Look up proposals for space based solar power and beamed interstellar transport. Once the cities are up and running production could switch to nuclear rockets (no atmosphere to worry about contaminating) for delivery of solar arrays with highly focused masers into orbit around the sun. Perhaps at some point machines could be sent to asteroids to mine and refine resources to manufacture more arrays. The idea being that these arrays beam the energy to Earth.

But the Earth has fled from the Sun, so it'd be a long, long ways off, I'd imagine, by the time -- if ever -- they were in any shape to do that at all.

 

[Ryan_m_b]

But the Earth has fled from the Sun, so it'd be a long, long ways off, I'd imagine, by the time -- if ever -- they were in any shape to do that at all.

Key point: Space is big, really really big.

If the cities aren't mostly complete by the time the atmosphere has frozen then they're all dead anyway. The way I see it long before the Earth leaves the solar system there will be time to deploy these stations en mass. Bear in mind how huge the solar system is, it's taken the Voyager probes decades to get to the edge and given the technology we're talking about having the precision to beam said energy to Earth doesn't seem like too much of a deal.

 

[sshai45]

Key point: Space is big, really really big.

If the cities aren't mostly complete by the time the atmosphere has frozen then they're all dead anyway. The way I see it long before the Earth leaves the solar system there will be time to deploy these stations en mass. Bear in mind how huge the solar system is, it's taken the Voyager probes decades to get to the edge and given the technology we're talking about having the precision to beam said energy to Earth doesn't seem like too much of a deal.

Yes, but I was thinking they'd need some time to develop the technology needed to launch with the VERY limited resources they'd now have, if they could ever do so. The space program we have now depends on having a large economy with free resources, no? (Note that the countries with big space programs also have big economies.)

 

[CCWilson]

Hard to pin down. One guy - a physics professor with an interest in astrophysics - said he thought it would be cool down quickly and he could calculate it but declined to do so. Another man said he thought it would be a slow process. So I'm still collecting data as best I can.

 

[Ryan_m_b]

Yes, but I was thinking they'd need some time to develop the technology needed to launch with the VERY limited resources they'd now have, if they could ever do so. The space program we have now depends on having a large economy with free resources, no?

Why are the resources very limited? They have a whole planet still. Again thinking of scale: we're proposing a society that has the capability to build, in short order, entire underground cities for millions of people that are technologically advanced enough to build and maintain closed ecosystems. Their industrial capacity will be huge, far greater than today.

So we've got a civilisation of millions with huge industrial capacity and a lot of experience and tools for digging. Doesn't sound like it would be too hard to mine the resources under the surface and build thousands of rockets.

 

[sshai45]

Why are the resources very limited? They have a whole planet still. Again thinking of scale: we're proposing a society that has the capability to build, in short order, entire underground cities for millions of people that are technologically advanced enough to build and maintain closed ecosystems. Their industrial capacity will be huge, far greater than today.

So we've got a civilisation of millions with huge industrial capacity and a lot of experience and tools for digging. Doesn't sound like it would be too hard to mine the resources under the surface and build thousands of rockets.

Yes, they would have the whole planet, but it'd be much more difficult to access than it is now. And didn't this guy mention in one of these threads that this was NOT supposed to be human civilization hundreds of years from now, but close to *today*? Or has he changed his mind on that?

 

[Ryan_m_b]

Yes, they would have the whole planet, but it'd be much more difficult to access than it is now. And didn't this guy mention in one of these threads that this was NOT supposed to be human civilization hundreds of years from now, but close to *today*? Or has he changed his mind on that?

He wants it to be near but if you look back through the thread you'll see some of the things that we've pointed out that this near future society is going to need: the technology to build and maintain sustainable closed ecosystems and industries to support a well organised society of millions. On top of that it all has to be built underground in a matter of years. Whatever this society looks like it's not going to be lacking in industrial power or technology (even if it is utilitarian with the only non-personal aesthetic artefacts/activities being what sociologists and psychologists think is necessary).

 

[CCWilson]

Out of curiosity have you worked out if it is possible/likely for the Earth just to wander off into interstellar space? I have a suspicion that an event of that much energy would devastate Earth even more. It seems more likely that Earth's orbit would become quite eccentric before leaving. I'm not sure of that though. The escape velocity for the solar system from Earth orbit is something like 40kmps, whatever it is that disturbs Earth's orbit has to impart that in the right direction (and it's still going to take many years to get anywhere).

I mentioned earlier in thread a short story that might help but I got the name wrong. It's called Minla's Flowers by Alastair Reynolds (though it's only available in anthologies).

One of the best tools for visualizing what a passing black hole would do was provided by DrStupid on another section of our PhysicsForum. It's initially set to show an object of one stellar mass throwing the Earth out of its orbit. If you click on "Stop simulation", you can change parameters to see what an object of different mass and different speed and position would do. I have no idea how accurate it is but it was greatly illuminating for me.

Thanks for that suggestion. I did find Minla's Flowers in a science fiction anthology and ordered it from Amazon. Should be here in a few days.

 

[Ryan_m_b]

Thanks for that suggestion. I did find Minla's Flowers in a science fiction anthology and ordered it from Amazon. Should be here in a few days.

No worries was the anthology Zima Blue?

 

[CCWilson]

No, the book is called "The New Space Opera". There were several that included that short story.

 

[Ryan_m_b]

No, the book is called "The New Space Opera". There were several that included that short story.

Cool, I've not got it so I might have to make an amazon purchase at some point too lol.

 

[sshai45]

He wants it to be near but if you look back through the thread you'll see some of the things that we've pointed out that this near future society is going to need: the technology to build and maintain sustainable closed ecosystems and industries to support a well organised society of millions. On top of that it all has to be built underground in a matter of years. Whatever this society looks like it's not going to be lacking in industrial power or technology (even if it is utilitarian with the only non-personal aesthetic artefacts/activities being what sociologists and psychologists think is necessary).

So he wants it to be near today, yet then how can it simultaneously have an industrial capacity "far" greater than today? That suggests a time centuries from now.

But I'd be curious about this: can one expect that with the population cut to maybe a thousandth of its original size, to still retain industrial capacity comparable to the entire U.S. of today, or whatever would be required for a big space program way bigger than the one of now?

 

[Ryan_m_b]

So he wants it to be near today, yet then how can it simultaneously have an industrial capacity "far" greater than today? That suggests a time centuries from now.

Exactly, this is why I've pointed out that the time frame is not workable. These cities are going to need three major things:

1) A sustainable closed ecosystem. Easier said than done as ecosystems are incredibly complex and we don't have much of a clue how to design one. We could try with artificial but that would require us knowing enough about ecosystems (and our place in them) to not only identify what is needed but somehow replicate it.

2) A model of social organisation that takes into account the optimum number and characteristics of skilled and skilled workers (see the other thread in this subforum about minimum populations) and puts them to work efficiently as well as taking care of social needs. The latter is as important as the former; societal failure modes are a whole lot more serious when everything is so enclosed and so fragile.

3) A technology and industrial base to support all this. Essentially these cities need to have a factory for everything plus redundancy. Think of the distributed industries on Earth now (take any modern technology near you and think of the huge distances and logistical chains that led to it being yours: from mining to refining to manufacture all via global transport and communication) and realize that they all have to be redesigned to fit "under one roof".

Lastly the reason it has to be so high tech is that pulling off an industrial feat of that size will require it on top of the technological know how it's going to need to keep the biosphere and extended phenotype going.

But I'd be curious about this: can one expect that with the population cut to maybe a thousandth of its original size, to still retain industrial capacity comparable to the entire U.S. of today, or whatever would be required for a big space program way bigger than the one of now?

A thousand doesn't seem to likely. Remember that the US is not self sufficient (that doesn't mean it couldn't be bar mining outposts but it would take a heck of a redesign and wouldn't be as efficient). If the US was 1000 times smaller in population what would give it about 300,000 people which IIRC is 100,000 less than NASA employed during the Apollo program.

 

[CCWilson]

sshai45, I never said that the industrial or technological capabilities would be greater than they are today. In fact, they would certainly be less, because of the shortage of materials locally and no outside suppliers of intermediate parts. On the other hand, they wouldn't go back to the stone age, either. They would try to maintain as much technology as possible. They would store raw materials and components. Each city would have a section for scientific and engineering research and a manufacturing complex and they would do what they could. In the long run they might be able to develop the ability to roam the surface and harvest raw materials and other supplies and make scientific advances, but in the beginning they would be in survival mode, with the production of sufficient food for everyone the principal concern.

 

[sshai45]

Exactly, this is why I've pointed out that the time frame is not workable. These cities are going to need three major things:

1) A sustainable closed ecosystem. Easier said than done as ecosystems are incredibly complex and we don't have much of a clue how to design one. We could try with artificial but that would require us knowing enough about ecosystems (and our place in them) to not only identify what is needed but somehow replicate it.

2) A model of social organisation that takes into account the optimum number and characteristics of skilled and skilled workers (see the other thread in this subforum about minimum populations) and puts them to work efficiently as well as taking care of social needs. The latter is as important as the former; societal failure modes are a whole lot more serious when everything is so enclosed and so fragile.

3) A technology and industrial base to support all this. Essentially these cities need to have a factory for everything plus redundancy. Think of the distributed industries on Earth now (take any modern technology near you and think of the huge distances and logistical chains that led to it being yours: from mining to refining to manufacture all via global transport and communication) and realize that they all have to be redesigned to fit "under one roof".

Lastly the reason it has to be so high tech is that pulling off an industrial feat of that size will require it on top of the technological know how it's going to need to keep the biosphere and extended phenotype going.

Thanks. But one doesn't want it too advanced, either, lest there be the possibility of interstellar flight. Yet an industrial capacity "far" larger than ours suggests a civilization "far" more advanced.

A thousand doesn't seem to likely. Remember that the US is not self sufficient (that doesn't mean it couldn't be bar mining outposts but it would take a heck of a redesign and wouldn't be as efficient). If the US was 1000 times smaller in population what would give it about 300,000 people which IIRC is 100,000 less than NASA employed during the Apollo program.

Hmm. However, I still wonder about this. The thing is, in these cities, just about everyone is going to be needed just to keep things going, for survival. Which doesn't leave many for doing something like a huge space program way, way bigger than the Apollo program.

 

[sshai45]

sshai45, I never said that the industrial or technological capabilities would be greater than they are today. In fact, they would certainly be less, because of the shortage of materials locally and no outside suppliers of intermediate parts. On the other hand, they wouldn't go back to the stone age, either. They would try to maintain as much technology as possible. They would store raw materials and components. Each city would have a section for scientific and engineering research and a manufacturing complex and they would do what they could. In the long run they might be able to develop the ability to roam the surface and harvest raw materials and other supplies and make scientific advances, but in the beginning they would be in survival mode, with the production of sufficient food for everyone the principal concern.

Yes, however ryan_m_b suggested they'd *need* industrial capacity way greater than today's.

 

[CCWilson]

By the way, here's DrStupid's gravity simulator. Fun to play with. http://www.drstupid.de/Newton.html?...o-Mars;2e30,-2e12,1.8e11,0,60000,0,0,o-Object

 

[Ryan_m_b]

sshai45, I never said that the industrial or technological capabilities would be greater than they are today. In fact, they would certainly be less, because of the shortage of materials locally and no outside suppliers of intermediate parts. On the other hand, they wouldn't go back to the stone age, either. They would try to maintain as much technology as possible. They would store raw materials and components. Each city would have a section for scientific and engineering research and a manufacturing complex and they would do what they could. In the long run they might be able to develop the ability to roam the surface and harvest raw materials and other supplies and make scientific advances, but in the beginning they would be in survival mode, with the production of sufficient food for everyone the principal concern.

It's not just a question of keeping as much technology as possible, they will need more advanced technology than we have! You are proposing that they construct things that we cannot construct today in an unbelievably short time span. It's going to require a lot of breakthroughs to get that done.

Also I have a problem with this idea that they will be in "survival mode". If you're building a self contained ecology for millions of people it's either going to work or it's not, there is no middle ground. That's not to say it isn't possible to have shortfalls but they have to maintain a biosphere. It has to be there with a carrying capacity equal or greater than their population number or they're dead.

The primary concern IMO isn't technological once the cities are built but psychological and social. How many people are going to have severe psychological trauma from loosing loved ones, their homes and the Earth in general? The medical authorities will constantly have to battle a population with widespread psychological needs which will be difficult as pretty much all of them will be suffering as well.

Thanks. But one doesn't want it too advanced, either, lest there be the possibility of interstellar flight. Yet an industrial capacity "far" larger than ours suggests a civilization "far" more advanced.

Not exactly. They will have technology more advanced than us but the main boon is from:

1) Having constructed concentrated industrial infrastructure capable of producing nearly anything en mass (this is to replace the globally distributed industries we have today)

2) The socioeconomic models that allowed these cities to be constructed in the first place. Think of the systems that would have to be invented and put into place to figure out what resources need to go where from across the world to invent and build these cities. With that experience under their belt this society will have far more efficient systems for megaprojects.

These cities are going to be huge. They're going to hold millions of people who are constantly organised into the most efficient arrangements to fulfil policy. They're going to have vast factories that can be put towards mass producing almost anything (they'll need that to build and maintain the cities). They're going to be very green, every available space will be covered with plants, animals, fungi, vats of microorganisms etc. They are going to be very monitored, every square metre is going to have to be monitored for air pressure/quality/temperature, all the organisms are going to have to be monitored for population levels and health with every interaction noted to model the health of the biosphere in general (with automatic and manual adjustments as required to keep it stable/human carrying). Essentially the economy of these cities will match a modern day developed nation. The production of rockets, solar panels, masers etc isn't too much of a drain compared to this.

However as I don't want to seem like all I bring is negative feedback I can envision that some of these cities might have to work flat out (i.e. nearly all their economy) to maintain their city. It could seem like they are constantly fighting a loosing battle. Though I still find this a little unbelievable (given the scenario it really does seem either make or break) this whole scenario is relying on hefty amounts of suspension of disbelief.

 

[CCWilson]

Ah - so you're saying, Ryan, that if we were tossed out of orbit five years from now, there would be difficulties? People would be upset? There would be technological difficulties to overcome?

Gee. I never thought of that.

 

[Ryan_m_b]

Ah - so you're saying, Ryan, that if we were tossed out of orbit five years from now, there would be difficulties? People would be upset? There would be technological difficulties to overcome?

Gee. I never thought of that.

That's a rather rude tone to use when I've tried to help you, especially when I've gone into quite a lot of detail and made a lot of suggestions rather than just point out "there will be problems". Why are you suddenly upset?

 

[CCWilson]

Sorry, but you seem to be missing the point that if we learned tomorrow that we would lose the sun in five years, we would have to do the best we could to keep humankind alive. It would be easier if we had fifty years to prepare, but that's not the situation I'm putting forward.

 

[Ryan_m_b]

Sorry, but you seem to be missing the point that if we learned tomorrow that we would lose the sun in five years, we would have to do the best we could to keep humankind alive.

The best we can do is not enough. Honestly if we find out the sun will be gone in five years then we're all dead. If you want to go with soft science fiction then sure you can handwave all the issues away but then you're left with the problem of a possibly plot breaking handwave.

 

[CCWilson]

The best we can do is not enough. Honestly if we find out the sun will be gone in five years then we're all dead. If you want to go with soft science fiction then sure you can handwave all the issues away but then you're left with the problem of a possibly plot breaking handwave.

I'm afraid that you are grossly overestimating the hopelessness of the scenario. I have no doubt that with a sufficient supply of energy from geothermal (or other) power, humans could survive for a good long time. The major difficulty I see is producing sufficient food long term; I'm confident that the other problems - and maybe the food issue - would be solvable by the large numbers of smart people brought on board.