On ZDNET an interesting article about Markforged – a company that is working on a mass production 3D printer. As we have previously pointed out on this site, 3D printing is along side with in situ resource utilization one of the key technologies that will be of critical importance of making space settlements independent from terrestrial imports.
Although Space colonization and genetic engineering are separate concepts and the creation of space habitats is perfectly possible without the use genetic engineering, we believe that genetic engineering is a key technology for the success of Space colonization. Continue reading Space colonization and genetic engineering
World population is expected to grow to nine to ten billion people around 2050. And all this people need to be fed, but arable land scarce. Most land suitable land is already in use, so the challenge is obvious. One of the proposed solutions is urban vertical farming, i.e. growing crops in skyscrapers. In this post I will question whether vertical farming is actually a good idea.
The Wikipedia article on vertical farming mention several advantages of this mode of agriculture. First there is the preparation for the future argument: since there will be more people, we will need more land for agriculture and one way to do this by stacking up several layers of greenhouses. The second argument is about increased production, since indoor conditions are controlled we can produce crops all year round. Which means a multiplication of productivity with several factors. Related to this argument is the fact that indoor farming in a skyscraper will eliminate most weather related problems. Ordinary greenhouses, however do this already.
The subsequent argument mentioned is about conservation of resources, which means that by switching to vertical farming large pieces of land can be “recovered” and brought back to a more “natural” state. Also deforestation and desertification will be halted, and the need for fossil fuel powered plowing, planting and harvesting will be reduced, saving fossil fuels and reducing carbon dioxide emissions.
The next argument goes that by indoor agriculture less pesticides and the like are needed, therefore food will be healthier. The last argument I want to mention is the energy argument. The proponents argue that by employing methane digesters the farm will be able to produce some of its own power needs.
Well, its true that by using organic waste as an energy source, some reductions in external power supplies can be made. But I do not think that will be quite significant. From the second law of thermal dynamics we know that in a closed system the total energy is constant, it can only change from one form to another. If we subsequently extract energy from such system, the amount of contained energy in the system is lowered. What crops do is, energetically speaking, converting solar energy into chemical energy (stored in sugars and starch). Should we initially consider a vertical farm as a closed system, if we then remove some crops (for sale) and the farm will lose energy, which should be replenished. With only biogas from organic waste from the farm, we will still lose energy. What we need is an external supply of energy.
Since vertical farms will put layers of crops atop of each other, they have to replace sunlight with artificial light. Some research shows that with proper lighting will increase production in comparison with sunlight (this is due to the fact that plants will only absorb light of certain frequencies, and all other frequencies [notably green] will be reflected). And this lights have to be powered. A lot of energy is required, for heating the building, air circulation, pumping water and lights. Actually there is only one energy source suitable for powering vertical farms, and it is not solar, bio or wind power. The answer is probably not the one which is favoured by vertical farm proponents. Only nuclear power plants are able to provide a stable and reliable power supply for vertical argrarians.
Since the members of the Vertical Farm movement are eager to point out how environment friendly their ideas are, it is quite remarkable to see that they do not tell how they want to power their plans. They only mention energy recovery through bio methane gas and saving energy by reducing transportation. But this is not enough, we need a good plan about how to power such structures and how to finance it. History provides ample examples of nice plans, but which failed because the were not properly explained (the notorious Freedom ship is a classic).
The need for feeding nine billions people is out of the question, everyone acknowledges this. The actual question is how to do this. Vertical farms are one solution, but what are the alternatives? My favorite is the saltwater greenhouse. This concepts relies on the Sun to evaporate seawater, which is thereafter liquefied and used for the crops, but for more details you should check this link.
The most suitable places for saltwater greenhouses are large pieces of desert. The Sahara is on the first place of candidate locations. The world’s largest desert is sparsely populated and receives more solar energy than any other place on this planet. Further its location is strategic. Only a modestly small proportion of the Sahara is needed to generate enough energy for the entire world. What I mean to say is that unlike the vertical farm concept this plan is much more realistic, it is clear how it is powered. And unlike vertical farms, it can be done at small-scale, after which it can be scaled up. Therefore it is possible to test in practice before investing large sums of money into the project.
What about the energy cost of transporting food from the Sahara the rest of the world? Well, energy enough in Northern Africa, I would say. Just converting solar energy into some fuel. There are a number of methods to produce so-called synthetic fuels. Actually there are plans to build large solar farms in North Africa which should be linked to the European Superlink.
But there are other solutions for solving the global food shortage. First we should note that a lot of the world agricultural production are crops for feeding livestock, by consuming less or no meat we need less land to feed the world population. Secondly we have to understand that the food problem is actually more about distribution rather than production, in fact the total world food production is enough to feed everyone. But since there is unequal distribution of wealth in the world, some people do not get what they need. Perhaps we should solve this problem politically rather than technologically.
Vertical Farming in space
This post, however, is about vertical farming on Earth. But this concept might have more potential for space colonization, I will work this out in an upcoming post on this blog.
This post was originally published on blogspot.com on April 23, 2012; updated June 13, 2014.
In this post I want to share some thoughts I have had for many years, concerning the ancient Greek city-state, or polis (plural poleis) and what we can learn from them.
Both O’Neill’s Island I and its main competitor the so-called Stanford torus are designed for some ten thousands of inhabitants, roughly the population of many small cities. And since space habitants of this kind can easily moved to any place within our (inner) Solar system, they can enjoy a great amount of isolation just by keeping distance from other space colonies. Furthermore the abundance of space resources makes economic self-sufficiency not only feasible but also very likely.
Here on Earth no country can turn to a policy of full autarky without paying a huge price. Effectively only very primitive societies can be autarkic without giving up current wealth. One reason of modern globalization is that highly technological industries require large amounts of various resources, of which many are both rare and spread over different parts of the world. Some resources are as good as exclusively found at one place on Earth. Some argue that this interdependence promotes world peace, while on the other hand we see that competition of scarce resources actually lead to many international conflicts.
In space there is a different situation, since there are a lot of recourse rich asteroids. Actually some “small” asteroids contains a few times more resources than anything ever dug up by Mankind, not only these asteroids have a huge abundance of resources but they also contain virtually all chemical elements needed by highly industrialized societies. A second difference is that competition among space colonies for resources will be low, due to great amount of asteroids, reducing tension among Spacer societies.
We can easily imagine that a small space colony, type Bernal sphere or Stanford torus is located near a small asteroid (dimension less than 1km). Such space society will be economically and politically independent from any other state (whether Spacer or terrestrial). This comes very close to the ancient Greek ideal of the polis: a political independent community of a few thousand people and economically self-sufficient.
Since the time of the ancient Greeks the ideal of small independent communities have repeatedly promoted by political activists. But these ideas and initiatives are repeatedly defeated in favour of the nation-state. A modern incarnation of this attitude is Communalism as conceived by Murray Bookchin. Bookchin, who stood in the anarchist tradition, opposed the nation-state, because it is undemocratic and a tool for corporate interest. Instead he argued that people should organize direct democracy at municipal level. And in a next stage, such municipalities should organize themselves into confederations, these confederations should compete with the Nation State for power. Confederations of municipalities differ from nations in an important way: the municipality is the primary political unit and the municipal citizens’ assembly is the Sovereign; the confederation is just an organization for cooperation and joint action by municipalities, and the representatives of the municipalities in the confederal council are purely coordinating and administrative.
Personally I believe that Communalism and its aims are not realistic, on Earth, because nation states are too well-organized and most terrestrial people don’t care about politics in general, and specially they don’t care about the Nation State. I suppose that most readers of this blog have never heard about Communalism before. On Earth I see no future for Communalism and related ideologies, but in Space Communalism and its idea may play a major role. Although I am not a Communalist myself (mainly because I disagree with its anti-capitalist nature), I believe that Communalism can provide valuable insights on how to organize Space colonies.
Some Space colonies may opt for Communalism, while other colonies will try other forms of government. But I believe there is a future for small polis based political communities in Space.
Inside view of a Bernal sphere
Outside view of a Bernal sphere