Science – Page 106 – a sibilant intake of breath

Random numbers

Truly random numbers are hard to find, as patterns tend to abound everywhere. This is problematic, because there are times when a completely random string of digits is necessary: whether you are choosing the winner of a raffle or generating the one-time pad that secures the line from the White House to the Kremlin.

Using random radio crackle, random.org promises to deliver random data in a number of convenient formats (though one should be naturally skeptical about the security of such services). Another page, by Jon Callas, provides further information on why random numbers are both necessary and surprisingly tricky to get.

This comic amusingly highlights another aspect of the issue.

The Great Dying

251.4 million years ago, the earth experienced the most severe extinction event ever recorded. The Permian-Triassic (P-Tr) extinction event (informally referred to as the Great Dying) involved the loss of 90% of all extant species. This included about 96% of all marine species and 70% of terrestrial vertebrate species.

There are a number of theories about what caused the event:

A comet or meteor impact
Massive volcanic activity
Continental evolution
A supernova destroying the ozone layer
Methane clathrate release

Some combination of such factors may well be responsible. Regardless of the initial cause, one of the defining elements of the P-Tr event was a high degree of global warming. Mean global temperatures increased by about 6°C, with much higher increases at the poles. This period also involved the large-scale failure of ocean circulation, leaving nutrients concentrated at the ocean bottom and an acute lack of oxygen in the sea. The latter was the product both of decreased circulation and the large-scale die off of the kind of phytoplankton species that now produce about 90% of the planet’s oxygen.

The study of such historical occurrences is useful, largely because it helps to improve our appreciation for how climatic and biological systems respond to extreme shifts. Just as the re-emergence of life after a forest fire and a clearcut may have some common properties, perhaps the patterns of decline and reformation after the P-Tr event can offer us some insight into macro level processes of ecological succession after traumatic climatic events.

Aurigid meteor shower

For those who missed the annual Perseid meteor shower, there is another chance to see some debris vaporizing in our atmosphere this week. The Aurigids are a much rarer shower, generated by comet Kiess (C/1911 N1) passing near the sun around 4 C.E. Gravity from the Earth and other planets sometimes creates dust trails that intersect with the Earth, as it moves through its orbit. The night of August 31st will be one such occasion.

Regrettably, there will not be much to see from eastern Canada. Even in the countryside, the incidence of meteors will peak at less than ten an hour. In Vancouver, however, those in the countryside can expect to see a sharp peak of activity between 4:00am and 5:00am, during which more than 200 meteors per hour should be visible. If you are looking for an excuse to escape all that city light pollution, this is an excellent one.

Aspiring amateur astronomers will find this page very informative. It includes tips on viewing, as well as a neat applet that lets you calculate the incidence of meteor activity in your location.

Greenhouse gas flowchart

The World Resources Institute has produced an excellent flowchart showing the activities that generate greenhouse gas emissions and the magnitude of those flows in terms of CO2 equivalence.

The data is from 2000, but I would expect the relative magnitudes to be reasonably similar now. This graphic provides a powerful and intuitive view into where the problem lies, and suggests areas where the greatest improvements could be made.

Real time ocean monitoring

The Neptune project, being led by the University of Victoria, is quite a considerable undertaking. The first stage of the plan is to make an 800km loop of fibre-optic and electrical cable and use it to connect five living room sized automated underwater data collection systems called ‘nodes.’ These will track fish stocks and undersea earthquakes, while collecting other kinds of data on an ongoing basis. This will be the first cabled ocean observatory with multiple nodes.

Ultimately, the system will expand to include 3000km of powered fibre-optic cable connecting a larger number of nodes, all capable of returning data in real time. Compared with systematic collection of data (go to a spot at set intervals and check what is happening) or sporadic collection (just use whatever data becomes available from whenever people happen to be in a place), real time data allows for different sorts of analysis and more comprehensive evaluations. The nodes will contain instruments including temperature meters, conductivity meters, pressure gauges, acoustic dopplers and hydrophones, current meters, wave sensors, electrometers, seismometers, cameras, nutrient monitors, sample storage containers, and autonomous robots.

The system should offer some useful data on migratory fisheries and whale movements, as well as the ominous rumblings of the Juan de Fuca plate, extending from British Columbia down to Oregon. It will also contribute to a more systematic understanding of ocean geology and ecology in general.

Films and fish stocks

According to Shifting Baselines, it seems that Charles Clover’s excellent book “The End of the Line” is being made into a documentary film.

That was the book that inspired me to go meet Dr. Daniel Pauly at the UBC Fisheries Centre, as well as go on to write the article that was recently published in the MIT International Review.

Hopefully, the release of the film will raise the profile of the issue a bit. As morally dubious as the factory farming of land animals is, it does not endanger the survival of these species. That is not true of the modern industrialized fishing industry. The collapse of fisheries in the Mediterranean and North Atlantic is just a sign of what is to come to all fisheries worldwide unless aggressive conservation measures are put in place and enforced.

Chronic disease worldwide

People tend to think of heart disease and cancer as the diseases of the rich world, while AIDS, malaria, and tuberculosis afflict the poor. The latter idea is certainly true: among those, only AIDS kills an appreciable number of people in rich states (though antibiotic resistant tuberculosis may start changing that).

Just because infectious diseases tend to kill a lot more people in poor states than in rich ones, it does not follow that infectious diseases are the greatest health threat there. According to the World Health Organization, heart disease and cancer kill more people in poor states, as well, and together cause 45.9% of all global deaths. Add in diabetes and other chronic diseases, and you find that 63.5% of all deaths are caused by chronic diseases, compared with 29.7% for all infectious diseases (injuries kill 9.3%).

A forecast for the period between 2006 and 2015 predicts that deaths from infectious diseases will fall by about 4% in poor countries, while deaths from chronic illnesses will rise by about 20%. Partly, this is the result of growing affluence – particularly the ability to afford cigarettes. People in China, Russia, and Indonesia already spend between five and six percent of total household income on cigarettes.

The Millennium Development Goals include two targets relating to infectious diseases:

Halt and begin to reverse the spread of HIV/AIDS
Halt and begin to reverse the incidence of malaria and other major diseases

While these are obviously worthy and important goals, there is a danger of funds not being well matched to where they can do the most good. Shedding a few misconceptions about the relative health challenges of rich and poor states may help avoid that. So too, the further recognition that lifestyle factors like diet, exercise, and smoking have an enormous influence on overall morbidity and mortality.

McIntyre and NASA data

There is a lot of talk in the media about how Steve McIntyre – an amateur scrutineer of climate statistics – found an error in data released by NASA. Specificically, it was mistankingly believed that data that had not been corrected for urban heat effects had been. This data pertains only to the United States and the correction implies that about 0.15 ºC of the observed warming there was just a statistical error. In itself, this would not get much attention. What does get attention is that this changes the rankings of the hottest recorded years in the United States. Rather than 1998 being the hottest recorded year in the United States, 1934 now wins. Many news sources are treating this data revision as though it demonstates a serious flaw in the overall quality of our climate understanding.

The Fourth Assessment Report of the Intergovernmenal Panel on climate change is based on a far broader collection of data than just NASA data pertaining to just the United States. As such, their overall conclusion that is barely affected by this change. Likewise, the worldwide figures for hottest years still cluster in the last decade. The report’s Summary for Policy Makers explains:

Eleven of the last twelve years (1995–2006) rank among the 12 warmest years in the instrumental record of global surface temperature (since 1850). The updated 100-year linear trend (1906 to 2005) of 0.74°C [0.56°C to 0.92°C] is therefore larger than the corresponding trend for 1901 to 2000 given in the TAR of 0.6°C [0.4°C to 0.8°C]. The linear warming trend over the last 50 years (0.13°C [0.10°C to 0.16°C] per decade) is nearly twice that for the last 100 years. The total temperature increase from 1850–1899 to 2001–2005 is 0.76°C [0.57°C to 0.95°C]. Urban heat island effects are real but local, and have a negligible influence (less than 0.006°C per decade over land and zero over the oceans) on these values.

This information is based on a broad collection of sources including satellites and ground stations around the world. It also incorporates evidence from ice cores and other historical indicators of temperature and greenhouse gas concentrations. What the McIntyre situation demonstrates is the degree to which perceived anomalies are seized on by people with pre-determined agendas to either support or refute the overall climate change consensus. While the data is not a statistical threat to that consensus, it does have the ability to foster doubt in the general public and among policy-makers, especially when presented out of context.

Having people out there scrutinizing the data is excellent, and a good check against the proliferation of misleading information. At the same time, it is necessary to be rigorous in our thinking about how one new piece of information affects the overall picture. Likewise, it is important to remain aware of the degree to which individual agendas influence how information is processed, and what responses it evokes.

Hollywood physics

Deficiencies in movie physics can be good fun to dissect and mock, but a recent paper suggests that they are less benign. “Hollywood Blockbusters: Unlimited Fun but Limited Science Literacy” suggests that the absurdities that abound in popular films actually weaken the people’s ability to understand how the world works. The paper concludes that:

Hollywood is reinforcing (or even creating) incorrect scientific attitudes that can have negative results for the society. This is a good reason to recommend that all citizens be taught critical thinking and be required to develop basic science and quantitative literacy.

Specific issues discussed in the paper include projectile motion, Newton’s laws, impulse, buoyancy, and angular momentum. Certainly, some films underplay the dangers of high falls and similar phenomena – as well as playing up the dangers of things like automobiles spontaneously exploding.

Personally, I would prefer a world in which movies portrayed all the sciences in realistic and accessible ways. Unfortunately, such films are in perpetual danger of being ignored in favour of flashy absurdities like the The Core or the egregious recent Star Wars films.

Reading these entertaining reviews is a good after-the-fact vaccine.

Ravenous pine beetles

According to an interview with the CBC given by Allan Carroll at Natural Resources Canada, there is not much hope of British Columbia containing the mountain pine beetles (Dendroctonus ponderosae) that have already killed 9.2 million acres of forest. He said that “Our estimates are that by about 2013 to 2015, the beetle will have killed about as much as 80% of the mature pine in the province and I don’t think we can really affect that now.” As the supply of Lodgepole Pine becomes eliminated, the beetles sometimes move on to Spruce and other species. If the beetles begin to target the Jack Pine of the boreal forest, Carroll says that it “could wipe out billions of trees all the way to the East Coast.”

These insects were mentioned here before, in the context of the effect of changing minimum temperatures on species ranges. Apparently, once they have reached their maximum cold tolerance, these beetles can endure temperatures of -40°C. It is significant cold events in the early and late winter – before their chemical defences have fully come on stream – that can lead to “very large amounts of mortality in the [beetle] population.” A few very crisp fall days would do a lot for western Canada’s forests.