Tag Archives: science

Lunar water comes from asteroids

On Science Daily we found an interesting article on the source of water on the Moon. A significant amount of lunar waters exist in the form of hydrated minerals and computer simulations show that asteroids are a more likely source of this water than comets. Comets contain water in the form of ice, while asteroids do in the form of hydrated minerals.

According to the article the impact velocity of a typical comet would cause most of its water content to evaporate. On the contrary hydrated minerals from asteroid impacts would be absorbed into the Moon’s regolith.

How to combat racism

On the website of The Guardian we found this important article. According to this article white people become less racial prejudiced when they move to ethnically diverse areas, as result of witnessing positive interactions between people of diverse ethnic backgrounds.There are no a priori reasons to assume the same is true for people of different racial groups.

This study is relevant for the governments of Space Settlements. They could reduce racial prejudices in their societies by careful allocation of residencies to settlers in order to create ethnically diverse neighbourhoods, and to prevent the creation of “china-towns”.

Space settlements can do so by introducing quotas which state that no more than a certain percentage, for example 15%, of the population of a certain neighbourhood can be of the same ethnicity. Further the government of a Space Settlement could use lottery to assign residencies to its immigrants. This will result in neighbourhoods which are representative for the whole population of the settlement.

Venus

For those who do not believe in hell, I have bad news: you are dead wrong. At any given moment this place is located between 41 million and 258 million kilometres away from Earth. Temperature over there is 462 degrees Celsius and its atmosphere is filled with acid. We call this place Venus.

At first sight Venus does not seem to be an interesting place for space colonists. In this post I will discuss the value of the second planet for future space colonization.

One of the most remarkable features of our twin-sister planet, is her thick atmosphere, (yes, this deserves her very own Wikipedia lemma). Her atmosphere’s main component is carbon dioxide (96.5%), followed by nitrogen (3.5%) and traces of other compounds.  One of these other compounds is sulphuric acid. This mineral acid is very corrosive, but nevertheless it is used in many important industrial processes. Hence the mining of sulphuric acid is quite interesting for space settlers.

Mining sulphuric acid from the atmosphere of Venus is in many aspects quite similar to mining helium 3 from the outer planets. So Venus might be used as a training ground for helium mining on, say, Uranus. Technologies developed for this economic activity can be used in the Outer Solar System, with modest adaptations.

But also Venus’s large nitrogen reserves are quite interesting. Nitrogen is essential for terrestrial life, and it’s one of the basic ingredients of fertilizers. Through the Baber-Bosch process ammonia is produced from nitrogen and hydrogen. And ammonia has, besides the production of fertilizers, many industrial applications.

And what to think of the enormous amount of carbon dioxide on Venus? Carbon dioxide can directly be used for growing crops, which utilize photosynthesis to convert water and carbon dioxide into biomass and oxygen. But these carbon dioxide reserves could also be used to produce graphene and synthetic diamonds. These substances have interesting properties for use in electronics.

In order to produce either graphene or diamonds, one has to reduce carbon dioxide to pure carbon. One way to do this is the Bosch reaction. In this process we let carbon dioxide react with hydrogen gas, the end product is carbon and water. Hydrogen gas has to be imported from outside Venus, but the water can be dumped on Venus itself, since there’s more than enough water in outer space.

At 50 km above the surface of Venus both temperature and atmospheric pressure are similar to those at Earth at sea level. But since carbon dioxide is has higher density than breathable air, the latter would be a lifting gas at Venus. A balloon, also known as aerostats, filled with air would float in the atmosphere of Venus. We can use such aerostats as a platform for our mining operations, and even as the site for processing the collected gases.

Though Venus herself is not suitable for colonization, her atmosphere is full of valuable resources for space settlements and their inhabitants. The greatest challenge to any mining activity in the atmosphere of Venus, is her relatively high escape velocity, which is slightly less than Earth’s.

Spanking ban

As long as I can remember, at least since the late 1990s, I am a (moderate) opponent of corporal punishment of children. In the debate about prohibiting this kind of child discipline, both sides have made both good and bad arguments. My position is that corporal punishment is not necessary, but in general also not very harmful if done properly. Until I came along an interesting article on Science Daily: College students more likely to be law breakers if spanked as children.

A study by Murray Strauss shows that university students who have been spanked as kids, even if they were raised in loving families, have a greater inclination towards criminal behaviour. Though Strauss affirms that children need guidance and discipline, physical punishment are not the way to achieve this.

But since I like to be the devil’s advocate, I want to formulate a possible point of critique. Strauss suggests that spanking causes criminal behaviour, or at least reinforces such behaviour. However, could it be possible that spanking is not the cause but instead the effect? Generally children got punished for misbehaviour, and crime is a kind of misbehaviour but enshrined by public law. If a person has a general inclination to misbehaviour all his/her life, it wouldn’t be surprising if that person would be both punished as a child as well inclined to commit crimes as an adult.

If that assumption would be true, there would be a statistical relation between spanking as a child and criminal behaviour, but not a causal one. This because both variables are in fact caused by a third variable. Of course, this is a hypothetical alternative explanation, but nevertheless not one you could easily put away.

A nice, but dangerous video

This video looks and sounds as the setting of a fantasy movie, but it’s in reality of video by NASA how Mars would have looked liked four billion years ago. Though this quite amazing from a scientific point of view, I am afraid that it will trigger Mars fanatics to pursue their dream of terraforming Mars. Though terraforming is a common trope in science fiction, it’s little more than that. Scientists know roughly what should be done to terraform a planet like Mars, but we do not know yet any feasible technology to accomplish this.

How high can we build in a space habitat?

Living in a space habitat is quiet different from living on the surface of a planet. On Earth our head is oriented outwards, i.e. our head is pointed away from the centre of the Earth. But in a space habitat our head is oriented inwards, pointing towards the centre. Therefore we cannot build higher than the distance between the wall of the habitat and its centre, but this is not the only, or even most important, restriction for the height of building in space habitats.

In a space habitat gravity is replaced by the centrifugal force, which is generated by rotating the habit around its axis. This (virtual) force is given by the following equation: Fcent = m(w^2)r (I have used ‘w‘ instead of the small omega, since I don’t know how to type Greek letters in WordPress), with m the mass of the object on which the force acts, w the angular velocity of the habitat and r the distance between the object and the axis. On Earth gravity is given by the equation Fgrav = mg, with g the so-called gravitational acceleration, which is (on average) g = 9.81 m/s^2.

If we want that the centrifugal force acting on the inner wall of the space habitat (which we will refer to as “street level”), we have to solve Fcent = Fgrav. Or

m(w^2)r = mg

We see that we can cancel m on both sides of the equation, and write

(w^2)r = g = 9.81

Since r is in fact nothing else than the radius of our space habitat (which would be in case of an O’Neill cylinder be 3,000 meter), and hence a design parameter, we can only play with the habitat’s rotational speed in order to fix the strength of the centrifugal force.

A consequence of the last equation, the larger the radius of a space habitat how smaller its angular velocity will be. But also that by a given w, the closer you are to the axis of rotation, the smaller the centrifugal force acting on you will be. At the axis of rotation the centrifugal force is zero.

The whole point of substituting gravity with centrifugation is to counteract the health effects of low or zero-gravity. Therefore the height of a building will be restricted by the minimum accepted level of gravity. Recall that in a space habitat we are building towards the axis. So the question of height becomes a question of what is the accepted minimum gravity?

Gerard O’Neill have suggested that 70 % of Earth’s gravity, or 0.7g is an acceptable minimum level of gravity. Our equations show that for a given space habitat the strength of the centrifugal force is linearly dependent of the distance to the axis of rotation. Hence 0.7g is present at 0.7r, or at 0.3r if we are counting from street level. Assuming r = 3,000m than we can erect building up to 900m (counted from street level).

In vitro blood?

Last month Dutch scientist Mark Post presented the first hamburger made from cultured meat. Today we received the news that the Dutch blood bank group Sanquin, is doing research to produce red blood cells in vitro, also known as erythrocytes.

Just as is the case with in vitro meat induced pluripotent stem cells are used. Only these stem cells aren’t directed to differentiate into muscle tissue, but into red blood cells. The involved researchers motivate this research as follows:

Culturing erythrocytes from immortal induced pluripotent stem cells (IPS) potentially solves the donor dependency problem and provides a tool to generate specific low immunogenic erythrocytes. (Sanquin, visited at September 20, 2013).

The production of blood in vitro, called hematopoieses by Sanquin, has several benefits. Blood transfusions have an associated risk for communicable diseases, therefore by using cultured blood instead of donor blood, the transmission of infectious diseases can be eliminated. It also reduce the number of blood donors required.

And this latter benefit is of great importance for space settlers. If as a result of some accident in a space settlement, blood transfusions are needed, in vitro blood might provide this without having to rely on blood transports from Earth. In a small and isolated community, classic collection of blood might prove to be insufficient in some cases. Typically only half a litre of blood is taken from an adult donor at a time, while some surgeries might require several litres of blood.

In vitro blood is just another technological development, which might help us to colonize our Solar System.

Developments in Solar energy technology

The whole idea of space colonization is founded on two facts: the abundance of extraterrestrial mineral resources and the availability of huge amounts of cheap Solar energy. There are basically two approaches to harvest Solar energy for space settlements: photovoltaic cells and solar-thermal power plants. The latter uses the heat from our Sun to heat a fluid, which is used to drive a turbine.

A challenge for photovoltaic arrays, is their efficiency. But there is exciting news from this field, according to The Science Daily, scientists from North Carolina State University have designed a method to increase solar array efficiency up to 45%. This would mean less Solar cells are needed to produce energy.

A proposal for the animal friendly production of eggs

Recently the first hamburger made of in vitro meat got much attention, not in the last place because Google founder Sergey Brin was revealed as the primary funder of this project. Much of the appeal of in vitro meat, is because this development would allow us to reconcile our desire to consume meat with our commitment to animal welfare. In vitro meat eliminates the need to kill animals, and it also reduce the number of livestock needed to meet the demand for meat.

But meat is not the only popular food obtained from animals. Eggs and dairy are other much consumed animal products. Even if by switching to in vitro meat will reduce the number of livestock held for meat, a large number is still required to produce milk and eggs.

And not only the number of animals needed is a problem from the perspective of animal welfare, but also the issue of young male animals. Since the latter are mostly valueless for dairy and egg industry, they are usually killed soon after their birth. But the male young account for half of the new-born animals.

In case for dairy the solution is quite simple, instead of using animal milk we could switch to plant milk. To “improve” plant milk we could genetically engineer plants to produce animal proteins such as casein. From plant milk one could produce all kind of dairy products such yoghurt or ice cream. I once read an article about extracting proteins directly from grass, which could be used for subsequent human consumption.

Eggs seem to be more difficult to replace, but like meat most consumption of eggs is in processed food. Eggs are used as binding or raising agents in many food products. Vegans and other people who do not consume eggs, have found several substitutes for eggs for these purposes, such as flax-seed and starch flour. By using these substitutes, the number of animals used for the production of eggs can be reduced.

But even if we are able to replace eggs in processed food products, there is still the “direct” consumption of eggs. The question is of course, if we can culture meat in a lab, can we cannot do the same thing with eggs? After all, the eggs we consume are nothing else than big cells. In vitro meat is produced by growing stem cells and turning those into muscle tissue. And as we have discussed here and here, stem cells can be turned into egg cells.

Once we have “artificial” (chicken) egg cell, we have still no (chicken) eggs. The challenge is now to simulate the processes which turn an egg cell into an egg in the laboratory. First we have to grow the egg, by feeding it nutrients. And subsequently, we have to give the grown egg a scale. But if this technology can be developed, we have a method to produce eggs for human consumption in a truly animal friendly way.

See also

Space colonization and vegetarianism – this post discusses the importance of vegetarian diets in space settlements.

Space colonization and in vitro meat – this post discusses the prospects of in vitro meat for space colonists.

Could in vitro meat save the whales?

Animal welfare is an important issue for Republic of Langrangia. How we treat our fellow living beings, is the litmus test of our humanity. One important issue is whaling. During the 20th century commercial whalers almost exterminated many whale species. Until in 1986 the International Whaling Commission put a moratorium on whaling.

Since then there are two camps: one side is for a permanent ban on whaling, arguing that the population of whales is still too small. The other side argues that some species have recovered enough to re-allow limited whaling. Since cetaceans are intelligent animals, we oppose the killing of these animals.

In-vitro meat is a recent scientific breakthrough, which allows people to produce meat in an animal and environmental friendly way. For this method of meat production there’s no need to kill animals, instead stem cells are taken from the animal through a biopsy. One stem cell can, according to the scientists involved, produce up to 10,000 kg of meat, which is in the order of the size of a medium-sized whale.

For research scientists perform regularly biopsies on living whales, and without killing them. Therefore whalers of the future shouldn’t have any trouble with obtaining whale stem cells for the production of in-vitro whale meat.

This approach would solve many issues: first, the IWC can prohibit the killing of whales for ever. Secondly, whalers do not lose their jobs, since they are still needed to collect tissue samples from whales. And consumers can buy whale meat with the knowledge that no whale has been killed and hence that whales will not be hunted to extinction again.