Re: [Vo]:Popular Mechanics predictions for the next 110 years
At 03:29 PM 12/16/2012, Jed Rothwell wrote: This kind of thing is such fun! See: http://www.popularmechanics.com/technology/engineering/news/110-predictions-for-the-next-110-yearshttp://www.popularmechanics.com/technology/engineering/news/110-predictions-for-the-next-110-years I have a book from 1890 with predictions by people such as Westinghouse for the year 1990. A lot of them were smack on target. In some ways it is not so difficult to predict the future. The latest issue of Sci. Am. is devoted to future predictions. Most of the authors wimped out. They did not even take a stab at future computers. One of them said that space-based cities would have to have low pressure, which might affect the health of children. What a nitwit! Does he really think we can build cities in space but we can't develop materials strong enough to hold 1 atm of air pressure? Well, the assumption that space colonies would have low ambient pressure is unwarranted. I was, as I've mentioned, the administrator of the L-5 society, back before 1980. The proposed colonies were designed by scientists who would be able to consider strength of materials. I can wonder how closely they looked at this, and perhaps some mistake was made. The vision was of large spheres, with habitation on the interior, living space would be at some level of effective gravity (from rotation) and atmospheric pressure was assumed, as I recall. The pressure would appear as a force against the interior of the sphere, as a bursting force. If we think of the surface as formed from panels held together, what would be the forces tending to separate them? My intuition is that the forces would not be all that large, compared to normal strength of materials; the huge collective force generated by 1 atm over a large surface is *distributed* over that surface. Even if the analysis were accurate, a solution would be to divide up the living space into modules, each one pressurised independently. We certainly know that can be done! (Jed, the problem is a 1 atm pressure over a large surface. If space colonies are as envisioned, there would be a very large, empty interior, not a vast array of columns and structures holding the whole thing together. The writer's analysis seems wrong to me, but I haven't seen it.)
Re: [Vo]:Popular Mechanics predictions for the next 110 years
Actually, we will _never_ build large space or Mars colonies, because we have Venus for second home. Venus is after initial costs cheaper place to live than Earth, because solar energy at Venus is free (far cheaper than e.g. thermal cold fusion electricity could be), because outside temperatures are optimal for solar cells and solar flux is very high. The pressure problem however is really difficult and it helps greatly if orbital habitats are kept at low pressure. I could not even imagine comfortable living in vacuum. Imagine landing with airplane at worst and multiply that with figure 100. Then you should get a feeling how radically uncomfortable pressure changes are at high vacuum habitats such as in Mars, Mercury and L1 points. There is no such thing as routine when we are dealing with high vacuum. There is also radiation hazard in orbital habitats. Of course ISS will get company and I would predict that in 2020's we are starting to build second generation space station with artificial gravity enabled into high lunar orbit. Perhaps into L1 point, what would be suitable anchor for lunar space elevator. Near Earth Asteroid material is relatively cheap to collect into high lunar orbit and it should compensate higher launch costs. In that Popular Mechanics article there was one very good and urgent prediction, that Connecticut could alone feed the world if advanced vertical farming projects are utilized. Vertical farming is the key idea why it is so cheap to live in Venus. For Earth as a living planet, vertical farming is essential, because we have already solved all environmental problems expect those that are related to horizontal agriculture. With advanced vertical farming there is no more such thing as environmental problem that is uncontrollable. —Jouni On Dec 16, 2012, at 10:29 PM, Jed Rothwell jedrothw...@gmail.com wrote: This kind of thing is such fun! See: http://www.popularmechanics.com/technology/engineering/news/110-predictions-for-the-next-110-years I have a book from 1890 with predictions by people such as Westinghouse for the year 1990. A lot of them were smack on target. In some ways it is not so difficult to predict the future. The latest issue of Sci. Am. is devoted to future predictions. Most of the authors wimped out. They did not even take a stab at future computers. One of them said that space-based cities would have to have low pressure, which might affect the health of children. What a nitwit! Does he really think we can build cities in space but we can't develop materials strong enough to hold 1 atm of air pressure? - Jed
Re: [Vo]:Popular Mechanics predictions for the next 110 years
Solar storms are apt to cook you on Venus along with increased orbital
dark/vacuum energy the closer you get to the sun.
I would choose Mars
Stewart
Darkmattersalot.com
On Sunday, December 16, 2012, Jouni Valkonen wrote:
Actually, we will _never_ build large space or Mars colonies, because we
have Venus for second home. Venus is after initial costs cheaper place to
live than Earth, because solar energy at Venus is free (far cheaper than
e.g. thermal cold fusion electricity could be), because outside
temperatures are optimal for solar cells and solar flux is very high.
The pressure problem however is really difficult and it helps greatly if
orbital habitats are kept at low pressure. I could not even imagine
comfortable living in vacuum. Imagine landing with airplane at worst and
multiply that with figure 100. Then you should get a feeling how radically
uncomfortable pressure changes are at high vacuum habitats such as in Mars,
Mercury and L1 points. There is no such thing as routine when we are
dealing with high vacuum.
There is also radiation hazard in orbital habitats.
Of course ISS will get company and I would predict that in 2020's we are
starting to build second generation space station with artificial gravity
enabled into high lunar orbit. Perhaps into L1 point, what would be
suitable anchor for lunar space elevator. Near Earth Asteroid material is
relatively cheap to collect into high lunar orbit and it should compensate
higher launch costs.
In that Popular Mechanics article there was one very good and urgent
prediction, that Connecticut could alone feed the world if advanced
vertical farming projects are utilized. Vertical farming is the key idea
why it is so cheap to live in Venus.
For Earth as a living planet, vertical farming is essential, because we
have already solved all environmental problems expect those that are
related to horizontal agriculture. With advanced vertical farming there is
no more such thing as environmental problem that is uncontrollable.
—Jouni
On Dec 16, 2012, at 10:29 PM, Jed Rothwell
jedrothw...@gmail.comjavascript:_e({}, 'cvml', 'jedrothw...@gmail.com');
wrote:
This kind of thing is such fun! See:
http://www.popularmechanics.com/technology/engineering/news/110-predictions-for-the-next-110-years
I have a book from 1890 with predictions by people such as Westinghouse
for the year 1990. A lot of them were smack on target. In some ways it is
not so difficult to predict the future.
The latest issue of Sci. Am. is devoted to future predictions. Most of the
authors wimped out. They did not even take a stab at future computers. One
of them said that space-based cities would have to have low pressure, which
might affect the health of children. What a nitwit! Does he really think we
can build cities in space but we can't develop materials strong enough to
hold 1 atm of air pressure?
- Jed
Re: [Vo]:Popular Mechanics predictions for the next 110 years
At 07:47 PM 12/16/2012, Jouni Valkonen wrote: Actually, we will _never_ build large space or Mars colonies, because we have Venus for second home. Venus is after initial costs cheaper place to live than Earth, because solar energy at Venus is free (far cheaper than e.g. thermal cold fusion electricity could be), because outside temperatures are optimal for solar cells and solar flux is very high. Okay, I'll provide the standard L5 Society response to this. Give me a few minutes to get that old engine running, it's a bit rusty. The pressure problem however is really difficult and it helps greatly if orbital habitats are kept at low pressure. I could not even imagine comfortable living in vacuum. Imagine landing with airplane at worst and multiply that with figure 100. Then you should get a feeling how radically uncomfortable pressure changes are at high vacuum habitats such as in Mars, Mercury and L1 points. There is no such thing as routine when we are dealing with high vacuum. The space colony locations proposed, for earth orbit, are L4 and L5. Get it straight! L1 has negative stability. Nobody is proposing living at low pressure, but some lower pressure, comparable to habitable places on Earth, might be okay. There is also radiation hazard in orbital habitats. Probably the biggest problem. Radiation shielding has been part of space colony proposals. Of course ISS will get company and I would predict that in 2020's we are starting to build second generation space station with artificial gravity enabled into high lunar orbit. Perhaps into L1 point, what would be suitable anchor for lunar space elevator. Near Earth Asteroid material is relatively cheap to collect into high lunar orbit and it should compensate higher launch costs. Actually, the standard Society proposal was to build a nuclear-powered railgun on the Moon and use it to launch lunar rock to a transshipment point, might have been L2, I forget. Okay, why space before Venus? Actually, at the time, living in floating colonies at high altitude on Venus wasn't being considered, I never heard of it. The argument for space was the same reason why Earth cities were preferably built near transportation typically major rivers or ocean ports. You want to build in a place it is easy to travel from. Easy to get to any destination from earth orbit. Hard to get to earth orbit from Earth. Hard from Venus. Once in space, you can use solar sails to move even very large mass, all you need is some patience. The original justification for the moon project and for space colonies at L5 was to work on satellite solar power stations. The materials would come from the moon, but people would actually live at L5. Expensive to get there, but cheap to return to earth, if you want. Also cheap to move the constructed satellite solar power stations to geosynch orbit. The plan, back before 1980, was to start replacing earth-based power with satellite solar power; the solar power would be sent with phased-array antennas to receiving antenna farms on the earth, they could be anywhere the land was available. The receiving antennas would be essentially raised wires, at a certain spacing, the signal would be tuned to them (and kept in focus by a return signal, if the return signal was lost, phase lock would be lost. The energy density in the beam, even in focus, would be enough to feel warm, and I wouldn't think one would want to be in it for long times, but the density below the antenna would be fine. Basically, one could farm below the antennas, which would not obstruct sunlight. This was seriously proposed and had some level of political support, but not enough. The budget was comparable to what was already being planned to be spent for new energy generation using non-renewable fuels; this would be clean and essentially indefinitely renewable. I saw lots of spurious objections, the most serious real one was the number of launch missions required to establish the basic presence in space. That *would* have an environmental impact. Hope was, eventually, to build a space elevator. (i.e., Clarke's idea.) That was optimistic, still is. The basic L5 project did not require new technology. For humans to live in space, the biggest expense is lifting *hydrogen*. Oxygen is readily available on the moon, as oxides. Hydrogen is scarce in space.
Re: [Vo]:Popular Mechanics predictions for the next 110 years
On Dec 17, 2012, at 6:46 AM, Abd ul-Rahman Lomax a...@lomaxdesign.com wrote: There is also radiation hazard in orbital habitats. Probably the biggest problem. Radiation shielding has been part of space colony proposals. Actually radiation shielding is simpler than what is previously thought, because Near Earth Asteroids contains lots of rubble that serves well as radiation shield. You want to build in a place it is easy to travel from. Easy to get to any destination from earth orbit. Hard to get to earth orbit from Earth. Hard from Venus. If we are to build colony for millions of people, I would guess that getting back from there is not important. People who move into Venus will stay there. In Venus there should be room for hundreds of billions of people in a long term. In Earth we are struggling with few billion (western) people, if there is not going to happen breakthrough in clean energy production. Solar electricity might get cheap enough also here on Earth to support civilization, but many people do not believe that the cost of PV cells will be halved every eight years ad infinitum. I believe that they do, but I will not give you any proofs. However, today energy production is utterly unsustainable, because energy production is based on fossil fuels and very unstable nuclear power. Therefore there is urge to migrate into Venus, where there is abundant energy resources. Once in space, you can use solar sails to move even very large mass, all you need is some patience. Modern ion engines are as good as solar sails. Such as well served Hall thrusters. There are also few promising concepts in drawing board. NEAs have plenty of hydrogen for ion propulsion purposes so it is not required to lift from Earth. Hope was, eventually, to build a space elevator. Earth bound space elevator is not good idea, because reusable rockets are cheaper to operate than space elevator. Also the development costs of reusability are lower and there is no need for qualitative breakthroughs in basic material science. And we do not have any means to estimate the safety aspects of space elevator. However in Moon we have possibility to construct space elevator in 2018, because it is possible within existing technology and it will cost only few billion dollars, including development costs. That is less than Curiosity rover! I would predict that space elevator even in moon will get obsolete in 2030's due to reusable space crafts and orbital refueling. But my estimation is that there is at least 10+ year window while space elevator in moon is profitable. For humans to live in space, the biggest expense is lifting *hydrogen*. Oxygen is readily available on the moon, as oxides. Hydrogen is scarce in space. Problem with moon is that there very little gravity. Orbital habitats are better, because artificial gravity could be more confortable. We do not even know how well human body will adapt into Mercury and Mars ⅓-gravity, but I would guess that well enough, as I am going to book one way ticket to Mars in 2013. However hydrogen is abundant. There is huge amounts of water-ice in Mercury and C-type Near Earth Asteroids and sufficient amounts of water ice in the moon. Basic specs for 1200 ton C-type NEAs: transportation cost to high lunar orbit (Δv 100-500 m/s) are 2 billion dollars (or less if Falcon Heavy will be as cheap as promised) and that will contain ca. 200 tons of water and 200 tons other volatiles such as nitrogen and carbon compounds. This is kind a silly, but there are billions of small (1200 tons) bodies near Earth that can be harvested as a resource. People just did not realize this before because we cannot see them. Currently orbits are calculated only for few dozen NEAs, but none of them are observed accurately enough that we could estimate the mass or type of NEAs. Hydrogen was thought to be scarce resource in space, because it was not found until recently. Therefore it has not made into scifi visions. Why Venus is ignored in all scifi visions is just something that I cannot understand. Even floating city in Star Wars relied on antigravity technology although it would be easy to float e.g. in Saturn where temperature, gravity and pressure are in goldilocks zone. Using hot hydrogen balloons for floating in Saturn is not anyway futuristic technology! —Jouni
