climate change activist and science communicator; photographer; mapmaker — advocate for a stable global climate, reduced nuclear weapon risks, and safe human-AI interaction
New discoveries, the scientific method, and all matters relating to the scientific study of the physical world
Nearly done with the book, it seems fair to say that Oryx and Crake is the kind of novel that demonstrates how fiction can better educate a person for the future than textbooks or well-meaning non-fictional treatises.
It’s an ugly and disturbing book, but it may also be an important one.
The tendency of gasoline to increase in price during the summer is well known. Partly, this reflects increased demand (which leads to an increased quantity sold at an increased price, given a particular supply curve). Partly, this is the consequence of how summer gasoline is a different blend of hydrocarbons. The reason for this is the need to prevent too much pressure from building up inside gas tanks as more of the liquid turns to vapour in the summer heat. This is standardized in terms of Reid vapour pressure (RVP): the pressure of any particular gasoline blend at 100°F (37.8°C) expressed in kilopascals, calibrated to a standard atmospheric pressure of 101.3 kPa.
RVP is used to specify which blends of gasoline are acceptable for sale at different ambiant temperatures. Gasoline with an RVP of over 14.7 will fairly easily pressurize gas tanks and gas cans in summer heat. It will also boil if left in open containers. As such, regulations require summer gasoline to contain less butane than the winter sort. This is on account of how butane is relatively inexpensive (making companies want to include more of it), but is also the most active contributor to vapour pressure. As such, the butane content of summer gasoline must be very low – one factor behind the higher price.
I learned all this from R-Squared, an energy blog that seems to be commonly cited. The blog makes one other important point: anyone considering storing cheap winter gasoline for use in the summer should consider the dangers of having the butane therein turn to vapour and start pressurizing the container in which it has been stored.
It says a lot about our society that the development of a vaccine for Human Papillomavirus has been greeted with controversy rather than appreciation. It is absurd that a treatment that has been shown to be effective in the prevention of cervical cancer is being interfered with out of misguided concerns that it will increase the incidence of teenage sex. It seems unlikely that many young woman make their decision about whether or not to engage in sexual activity with the possibility of HPV-induced cervical cancer as a major consideration. (If they do, there are plenty of other STIs to give them pause.) Even if it could be documented that a vaccination program would increase teenage sexual activity to some appreciable degree, a very strong argument can be made that preventing the pain and death associated with cervical cancer is an outcome of sufficient importance to justify the choice to vaccinate. Furthermore, the overall response smacks of sexual double standards. If this were a vaccine that had a strong preventative capacity for both men and women, it seems unlikely that there would be so much furore about its administration.
The tactic of trying to alter the decision-making of teenagers through the reduced availability of life-saving medicines is hardly a behaviour that should be promoted or tolerated. The Globe and Mail gets it essentially right in a recent article, arguing that the purpose of a public health system is: “seizing opportunities to avoid needless death, to improve quality of life when we can and to extend it wherever and whenever we can.” Hopefully, the political opposition surrounding HPV vaccination will be overcome, and the procedure will become as routine as vaccination against Measles or Hepatitis B (itself largely transmitted through unprotected sex).
Melting sea ice was mentioned here recently. According to the MIT Technology Review, a team at the University of Kansas is building an unpiloted airplane designed to conduct detailed RADAR surveys of the Arctic and Antarctic ice sheets. In particular, the plane will look to see whether water has collected between glaciers and bedrock – a situation that can lead to their very rapid disintegration.
If things go according to plan the vehicle – dubbed ‘Meridian’ – should conduct its first survey next summer. Given the potential importance of melting ice for climatic feedback loops, anything that improves the quality of data available should be applauded.
In the most common system of taxonomy, as we should all have learned in high school, human beings are Animalia Chordata Mammalia Primata Hominidae Homo Sapiens. The first bit essentially means that we eat something other than sunlight. The second bit means we are descended – like all other vertebrates – from Pikaia gracilens. This creature lived about 570 million years ago and was part of the Cambrian explosion: so spectacularly displayed in the Burgess shale near the border of British Columbia.
Pikaia was initially mis-categorized as a worm. Now, it seems that the combination of segments, muscles, and a flexible dorsal rod embodied in this little creature may mean that it was the first vertebrate: the template for all those alive today. From the first vertebrate species, all amphibians, reptiles, birds, and mammals evolved. From tuna fish to orangutan, we may all be descendents of Pikaia. Writing about the animal in Wonderful Life, Stephen Jay Gould highlights both its huge evolutionary legacy and the degree to which it arose as the result of many change occurrences. If we could go back all those millions of years and let time unroll again, it is highly likely that we would have a profoundly different world at the end.
You can begin to imagine how staggeringly different the contemporary world would be if this little creature hadn’t survived and spread. The old view of evolution as a linear and predictable progression towards ‘higher’ organisms – a surprisingly common teleological view – is laid to rest by the contemplation of the degree to which chance can nudge history down one or another track.
September 26th is the next full moon. That night, I recommend getting hold of a pair of field glasses and having a look at our closest significant stellar neighbour. In particular, note the large impact crater near the moon’s south pole. The Tycho Brahe crater was determined to be about 100 million years old, on the basis of samples collected by the Apollo 17 mission. While such craters soon fall victim to erosion from air and water on Earth, they are well preserved on the airless moon.
Such craters are not just of geological interest. They testify to the reality of impacts from comets and asteroids. A sufficiently large such strike could have devastating effects for humanity. In 2029, we will get a reminder of how close some objects are to hitting us, when the 99942 Apophis asteroid will pass so close to the Earth that it will be between communications satellites in geostationary orbits and us. For a while, this asteroid topped the Torino impact hazard scale. NASA estimates that the impact of Apophis would be equivalent to the explosion of 880 megatonnes of TNT: about 58,000 times the yield of the atomic bomb dropped on Hiroshima.
There is a small but real chance that the close pass of Apophis will alter its course such that it hits us on its next pass, in 2036. In response, a spaceflight subsidiary of EADS called Astrium is proposing a mission to learn more about the asteroid, study its composition, and investigate options for deflecting its orbit, if necessary.
In one sense, we are lucky with Apophis. It was discovered back in 2004 and has since had its orbit accurately tracked. A comet, by contrast, is essentially invisible until proximity to the sun causes it to melt and produce a tail. It is entirely possible that such an object could strike the Earth with little or no warning whatsoever.
Carbon capture and storage (CCS) is a collection of technologies often mentioned in connection with global warming. Essentially, the idea is to capture the carbon dioxide emitted by things like power plants and then sequester it indefinitely in some sort of geological formation, such as a mined salt dome. While this idea is worthy of discussion in itself, my focus here is a number of approaches often described as CCS, but which do not achieve the same long-term result.
Some people have proposed that, rather than burying carbon underground, we just pump it into the sea. One option I am not going to discuss now is making big pools of liquid carbon dioxide in the very deep ocean. Rather, I will address the idea of using pipelines from shore or trailing from ships to release CO2 about 1000m down. Another alternative with similar effects is to make huge chunks of dry ice and throw them overboard, hoping most of the carbon will sink. Rather than being a type of CCS, these activities migtht be more accurately called ‘oceanic dumping of CO2.’
A matter of equilibrium
The problem here is both fundamental and intuitive. Think about a large plastic bottle of cola. With regards to the carbon dioxide, there is an equilibrium that exists between the amount dissolved in the liquid and the amount that is part of the air at the top of the bottle. As long as the system is closed (the cap is on), the amount of gas in air and water will trend towards that equilibrium point and, once the balance is achieved, stay there. This is what chemists mean when they say that equilibrium states display ‘constant macroscopic properties.’ CO2 from the water is still moving into the air, but it is now doing so at precisely the same rate as CO2 from the air is moving into the water. This is inevitable because if one rate were higher, the relative concentrations would change, and would continue doing so until the equlibrium was reached.
Now imagine that we change the equilibrium. If we take the cap off the bottle, the air inside mixes immediately with the air outside. Since the air inside has more CO2 than the air outside (because some of it has come out of the cola), this mixing causes the concentration of carbon dioxide at the surface of the cola to fall (we are ignoring the effects of atmospheric pressure in this analogy). As a consequence, the cola will start to release CO2, trying to get back to the old equilibrium between cola-dissolved and air-mixed gas. Since there is a lot more air, the equilibrium eventually reached will involve a lot less gas-in-cola. The cola goes flat. In the alternative, if we put a chip of dry ice into the cola and kept the cap on, a new equilibrium would eventually be reached in which both the cola and the air include a higher concentration of CO2.
Consequences
Dumping CO2 in the ocean thereby achieves two first-order effects. Firstly, it carbonates the sea, making it more acidic. Oceanic acidification is worrisome enough without such a helping hand. Secondly, it eventually results in an air-water balance of CO2 that is identical to the one that would have occurred if the CO2 started in the atmosphere. No matter which fluid it begins in, the same amount of CO2 at the same pressure will eventually result in the same balance between air-mixed and water-dissolved gas. It is just a matter of time. This is an important concept to understand, as it is the very heart of physical and chemical equilibria.
One big second order consequence results from this. If we do build such pipelines and do start carbonating the sea, people may decide that very carbon intensive technologies (such as coal generation or, even worse, Coal-to-Liquids) are environmentally acceptable. Using them in combination with oceanic dumping will inevitably have the same long-term atmospheric consequence as dumping the CO2 directly into the air.
Now, there is one reason for which oceanic dumping might be a good idea. Imagine there is some critical threshold for the atmospheric concentration of CO2: stay below it and things are reasonably ok, go above it and things all go wrong. In this scenario, it makes sense to store a bunch of CO2 and release it little by little. Of course, this only makes sense if we (a) only do this with CO2 we were inevitably going to release anyway (no new coal plants) and (b) aggressively cut future emissions so that the slow leak will not make us cross the threshold. Suffice it to say, this isn’t the kind of usage most advocates of CCS have in mind.
When cosmic rays collide with molecules in the upper atmosphere, they produce particles called muons. About 10,000 of these strike every square metre of the earth’s surface each minute. These particles are able to penetrate several tens of metres through most materials, but are scattered to an unusual extent by atoms that include large numbers of protons in their nuclei. Since this includes uranium and plutonium, muons could have valuable security applications.
Muon tomography is a form of imaging that can be used to pick out fissile materials, even when they are embedded in dense masses. For instance, a tunnel sized scanner could examine entire semi trucks or shipping containers in a short time. Such tunnels would be lined with gas-filled tubes, each containing a thin wire capable of detecting muons on the basis of a characteristic ionization trail. It is estimated that scans would take 20-60 seconds, and less time for vehicles and objects of a known configuration.
Muons have also been used in more peaceful applications: such as looking for undiscovered chambers in the Pyramids of Giza and examining the interior of Mount Asama Yama, in Japan.
Water scarcity is a frequently discussed probable impact of climate change. As glaciers and snowcaps diminish, less fresh water will accumulate in the mountains during the winter; that increases both flooding (during wet seasons) and drought. Higher temperatures also increase water usage for everything from irrigation to cooling industrial processes. Given the extent to which the world’s aquifers are already depleted (see: Ogallala Aquifer), relatively few additional natural sources exist.
The big alternative to natural sources is the desalination of seawater. This is done in one of two ways: using multistage flash distillation or reverse osmosis. About 1,700 flash distillation plants exist in the Middle East already, processing 5.5 billion gallons of seawater per day (72% of the global total). These plants use superheated steam, a by-product of fossil fuel combustion, to pressurize and heat a series of vessels. As salt water flows into each successively lower pressure vessel, it flash boils. Condensers higher in the vessel cause the fresh water to precipitate out from the hot pressurized air solution. This is a simple process, but an energy intensive one.
Reverse osmosis, by contrast, uses a combination of high pressure pumps and specialized membranes to desalinate water. Essentially, the pressure drives fresh water through the membranes more quickly than the accompanying salts. As such, it is progressively less saline with each membrane crossing. In this process, there are both relatively high energy requirements (for high pressure pumping) and the costs associated with building and maintaining the membranes. Because it can be done at different scales, portable reverse osmosis facilities are the preferred option for combat operations or disaster relief.
Unfortunately, both processes are highly energy intensive. Particularly when that energy is being generated in greenhouse gas intensive ways, this is hardly a sustainable solution. Part of the solution is probably to sharply reduce or eliminate water subsidies – especially for industry and agriculture. More transparent pricing should help ensure that the whole business of desalination is only undertaken in situations where the need for water justifies all the expenses incurred.
This rather heart-wrenching article from the New York Times discusses the shortage of pain-killing opiates for medical care in the developing world. This is more the consequence of (seemingly misguided) policies than of poverty. The issue was touched upon here earlier, as part of this discussion on the Afghan opium crop.