Science – Page 73 – a sibilant intake of breath

Colour temperature and photography

One way in which colours are categorized is according to the temperatures at which materials emit them, when heated in a vacuum. The phenomenon of warm things emitting light can be observed readily: for instance, when a bar of iron is heated from red, to orange, to yellow, to white. Some of the key colours photographically are those akin to the light of the sun around noon (about 5500° Kelvin) and the light from incandescent bulbs (about 3300° K). Just as with the heated iron bar, the hotter the light source, the ‘cooler’ the temperature appears: ranging from reds and oranges at low temperatures up to greens and blues. This can be a bit confusing, since the colours artists describe as ‘warm’ are actually produced by low temperatures, and vice versa.

Virtually all digital cameras have the ability to adapt to different colour temperatures. This is important because our eyes generally make the correction automatically. Looking at a scene under fluorescent lights, it doesn’t seem as green to us as it really is – and will appear on film or an uncalibrated digital sensor. Exactly how you set the white balance on your camera varies by model and manufacturer, but it is worth checking the manual over.

In addition to being used to correct for the dominant type of lighting in a scene, colour balance can be set so as to create a desired look that may not have been present in the original scene. For example, intentionally using the white balance for warm light (low temperature) in a scene with cool light (high temperature) exaggerates the cool light in the scene. As a result, you get a very cool looking photo like this one. By contrast, intentionally using the white balance for cool light (high temperature) in a scene that already has fairly warm light will exaggerate the warm light, as with this photo.

For users of Canon cameras, here is an easy way to try this out:

First, head out on a cold winter’s day and find a wintery looking scene.
Then, go into the white balance setting for your camera. If you have a point and shoot camera, this is normally done by setting the control dial on your camera to ‘P,’ then pressing the ‘Func. Set’ button in the middle of the wheel on the back. Scroll down once and you should be in the white balance menu. Press the ‘right’ button until you have ‘Tungsten’ selected.
If you have a digital SLR, there is usually a dedicated white balance button on the back, labelled ‘WB.’
Shoot the winter scene with that setting, and you will get a cool blue looking result.
Secondly, try shooting a warmish scene (such as one taken around sunset outside) with the camera set to ‘Cloudy.’ That will make it look even warmer, which is sometimes attractive.

When you choose a colour balance setting on your digital camera, you are telling it how to process the raw data from the sensor into a JPG image. Since the raw data isn’t normally retained, this is an irreversible choice (though it is possible to approximate a white balance change using software like Photoshop). For cameras capable of recording the data from the sensor as a RAW file, you will be able to select whatever white balance you like after the photo has been taken. Thanks to CHDK, a great many Canon cameras (including inexpensive point and shoot models) can be given this capability.

Incidentally, the matter of what wavelength of light is emitted by objects of different temperatures is a key part of the physics of climate change. One neat thing about science is the way you often run into aspects of one field that are relevant somewhere very different.

Climate in 2009: predictions

Two related events are likely to dominate climate news for 2009: the first year of the Obama administration and the UNFCCC negotiations in Copenhagen. Arguably, the biggest open question is just how dedicated Obama will be to domestic and international climate change action. It may be that he lives up to the high expectations of the environmental community, setting the stage for the rapid deployment of a cap-and-trade carbon pricing system in the United States and playing a constructive role in the creation of an international legal instrument to succeed the Kyoto Protocol. It may also be that his focus lies elsewhere, or that Congressional opposition makes his platform harder to implement. The Obama administration failing to make climate a priority issue from the outset is probably the most likely ‘bad news’ climate story of 2009, whereas successful domestic and international engagement is probably the most likely ‘good news’ story.

American re-engagement with the UNFCCC process is a necessary condition for progress, but it will not be sufficient in itself. Much depends on whether India and China can be brought into the agreement, as well as whether deforestation can be successfully incorporated into a new accord. Given the urgency of reducing emissions (starting the long path to stabilizing atmospheric concentrations of greenhouse gasses), it must be hoped that all the key states will rise to the challenge and develop a fair and effective approach.

If there are going to be big climatic surprises in 2009, they are more likely to be physical than political. It is nearly certain that there will be strange and destructive weather somewhere, and that at least some people will attribute it to climate change (whether plausibly or not). A big surprise could take the form of an extreme weather event, or simply the sharp acceleration of a tend such as glacier loss, permafrost melting, or changes in precipitation patterns.

With luck, 2009 will be seen as the year in which the world really began turning the corner towards emissions reductions. Most of the governments most bitterly opposed to action on climate change have been eliminated, and an accord between the big players (the US, China, Japan, Europe, etc) would have the momentum to drag everyone else along. The road ahead will continue to include shifts in policy – as well as very active debates on who should bear which costs – but the general outlines could be affirmed this year and global implementation could begin in earnest. Those broad outlines include the need for both total and per-capita emissions to start falling globally (perhaps with a brief period of residual growth in very poor states), that per-capita emissions should converge between all states, and that many of the costs of global mitigation and adaptation be borne by the societies that have created the problem.

For the sake of all future generations, let’s hope this will be a year of great progress.

Grid technologies to support renewable power

The MIT Technology Review has a good article about renewable energy and the ways electrical grids will need to change in order to accomodate it. Both key points have been discussed here before. Firstly, we need high voltage low-loss power lines from areas with lots of renewable potential (sunny parts of the southern US, windy parts of Europe, etc) to areas with lots of electrical demand. Secondly, we need a more intelligent grid that can manage demand and store some energy in periods of excess, for use in times when renewable output falters.

The article highlights how the advantages of a revamped grid are economic as well as environmental:

Smart-grid technologies could reduce overall electricity consumption by 6 percent and peak demand by as much as 27 percent. The peak-demand reductions alone would save between $175 billion and $332 billion over 20 years, according to the Brattle Group, a consultancy in Cambridge, MA. Not only would lower demand free up transmission capacity, but the capital investment that would otherwise be needed for new conventional power plants could be redirected to renewables. That’s because smart-grid technologies would make small installations of wind turbines and photovoltaic panels much more practical. “They will enable much larger amounts of renewables to be integrated on the grid and lower the effective overall system-wide cost of those renewables,” says the Brattle Group’s Peter Fox-Penner.

In short, a smarter grid holds out the prospect of overcoming the biggest limitation of electricity: that supply must always be exactly matched to demand, and that prospects for efficient storage have hitherto been limited. The storage issue, in particular, could be profoundly affected by the deployment of large numbers of electric vehicles with batteries that could be used in part as an electricity reserve for the grid.

Providing incentives for the development of a next-generation grid (as well as removing some of the legal and economic disincentives that prevent it) is an important role for governments – above and beyond the need to put a price on carbon. While carbon pricing can theoretically address the externalities associated with climatic harm from emissions, it cannot automatically deal with the externalities holding back grid development, which include the monopoly status of many of the firms involved, issues concerning economies of scale, the fact that the absence of transmission capacity restricts the emergence of renewable generation capacity (and vice versa).

The full article is definitely worth reading.

Liquid lenses for low-cost eyeglasses

Joshua Silver – a retired Oxford professor – has developed a kind of eyeglasses that can be easily ‘tuned’ for a particular individual in the field. This is possible because the glasses contain sacs of liquid silicone and have syringes attached, allowing fluid to be added or removed. Changing the quantity of fluid effectively adjusts the kind of correction provided by the lenses, allowing them to address any degree or short- or long-sightedness.

10,000 pairs have already been distributed in Ghana, and there are plans to distribute 1,000,000 in India in 2009. Silver ultimately aims to produce enough glasses for 100 million people a year.

The science section at the Rideau Chapters

The science section at the Rideau Centre Chapters always depresses me. It is often the most disorganized section of the store – tucked, as it is, in the very back corner. Books have frequently been relocated by customers and not re-shelved by staff, and the organizational system is deeply flawed even when properly implemented. For one thing, it has too many confusing sub-sections. It hardly makes sense to have a single shelf set aside for ‘physics’ books, when it is almost impossible to guess whether a specific tome will be in ‘physics,’ ‘mathematics,’ or the catch-all ‘science’ category. To top it all off, the catch-all category has been alphabetized in a bewildering serpent pattern, twisted back against itself and interrupted with random intrusions.

My two final gripes are that the science section is mysteriously co-mingled with the section on pet care (our most sophisticated form of understanding about the universe, lumped in with poodle grooming) and that the science section contains so many books of very dubious scientific merit, such as paranoid and groundless exposes on how MMR vaccines supposedly cause autism (they don’t, though they have saved countless infant lives).

While commercial pressures may legitimately dictate that the pilates section be more accessible, better organized, and more well-trafficked than the physics or biology sections, it is nonetheless saddening.

Torture, psychology, and the law

For the darkest day of the year, a couple of torture-related items seem appropriate. Firstly, there is this New York Times piece, which argues that senior officials from the Bush administration should be charged with war crimes, for authorizing and enabling torture. The editorial argues that there is no chance that prosecutions will be sought under an Obama administration, but that he ought to clarify the obligation of the United States and its agents to uphold the Geneva Conventions, as well as reverse executive orders that “eroded civil liberties and the rule of law.”

The prospect of high-level American decision-makers being put on trial for authorizing torture is so unlikely that it is a bit difficult to even form an opinion about it. At the same time, it is likely that nobody thirty years ago would have anticipated the trials at the International Criminal Tribunal for Rwanda (ICTR), International Criminal Tribunal for the former Yugoslavia (ICTY), or International Criminal Court (ICC). There is no clear reason for which high political office should be any impediment to being tried for war crimes, but it is very unclear how any such prosecutions would fare in the United States. It would certainly be seen as a ‘political’ act, and any connections with international law would likely be the targets for special criticism and scorn from some quarters.

The other story worth mentioning is an experiment conducted by Dr Jerry Burger, of Santa Clara University. It was a less intense re-creation of Milgram’s famous experiment on obedience to authority. Like Milgram, Burger found that a startling proportion of the population is willing to torture a fellow human being as part of a scientific experiment. This is when the only pressure placed upon the subject of the experiment is the authority of the actor pretending to conduct it. That naturally makes one nervous about what people would be willing to do when they felt an urgent and important issue justified it, as well as when far stronger sanctions could be brought against them if they did not proceed.

The nature and future of wind power

This Economist article discusses the history, technology, and future of wind power. It includes a fair bit of useful information, particularly about integrating wind into the broader energy system:

In addition, the power grid must become more flexible, though some progress has already been made. “Although wind is variable, it is also very predictable,” explains Andrew Garrad, the boss of Garrad Hassan, a consultancy in Bristol, England. Wind availability can now be forecast over a 24-hour period with a reasonable degree of accuracy, making it possible to schedule wind power, much like conventional power sources.

Still, unlike electricity from traditional sources, wind power is not always available on demand. As a result, grid operators must ensure that reserve sources are available in case the wind refuses to blow. But because wind-power generation and electricity demand both vary, the extra power reserves needed for a 20% share of wind are actually fairly small—and would equal only a few percent of the installed wind capacity, says Edgar DeMeo, co-chair of the 20% wind advisory group for America’s Department of Energy. These reserves could come from existing power stations, and perhaps some extra gas-fired plants, which can quickly ramp up or down as needed, he says. A 20% share of wind power is expected to raise costs for America’s power industry by 2%, or 50 cents per household per month, from now until 2030.

In 2007, 34% of the new electricity generation capacity that came online in the United States was in the form of wind turbines; China has doubled its capacity every year since 2004. 20% of Danish electricity already comes from wind, along with 10% in Spain and 7% in Germany. Given aggressive construction plans in Asia, North America, and Europe, wind power definitely looks like a technology with a big future.

Energy usage and the US Department of Defence

This article on space solar power (collecting energy from sunlight using one or more satellites in geostationary orbit, then beaming it down to Earth using microwaves) contains some interesting information on American military logistics in Iraq:

The armed forces are America’s single greatest consumer of oil. The Department of Defence delivers 1.6m gallons (7.3m litres) of fuel a day—accounting for 70% by weight of all supplies delivered—to its forces in Iraq alone, at a delivered cost per gallon of $5-20. It also spends over $1 per kWh on electric power (ten times the domestic civilian price) in battle zones, because electricity must often be provided using generators that run on fossil fuels.

This helps explain why militaries have such a keen interest in new energy generation and efficiency technologies.

The information on space solar power is also quite interesting. It actually seems to be a bit less infeasible than I thought, though the launching costs remain a very significant barrier.

Evidence of a positive climate change feedback in the Arctic

A study being presented at the annual meeting of the American Geophysical Union claims to have found the first concrete evidence of ‘arctic amplification’ – the phenomenon in which the loss of sea ice exposes water that reflects less sunlight than the ice did, thus causing further warming:

Climate-change researchers have found that air temperatures in the region are higher than would be normally expected during the autumn because the increased melting of the summer Arctic sea ice is accumulating heat in the ocean. The phenomenon, known as Arctic amplification, was not expected to be seen for at least another 10 or 15 years and the findings will further raise concerns that the Arctic has already passed the climatic tipping-point towards ice-free summers, beyond which it may not recover.

As with many of the other things happening in the Arctic, the phenomenon is not unexpected but the timing is. Partly, that reflects the imperfect (or totally absent) integration of feedback effects into climatic models.

As with so much other Arctic news, one can only hope that this will be a reminder of the urgency of mitigating greenhouse gas emissions. It is possible that doing so is more urgent than addressing the ongoing financial crisis and, from a long-term perspective, it is certainly a lot more important.

Fatih Birol on peak oil

In an interview with British journalist George Monbiot, Fatih Birol, the chief economist of the International Energy Agency made the following predictions about when peak oil output for non-OPEC and OPEC states would be reached:

“In terms of non-OPEC [countries outside the big oil producers’ cartel]”, he replied, “we are expecting that in three, four years’ time the production of conventional oil will come to a plateau, and start to decline. … In terms of the global picture, assuming that OPEC will invest in a timely manner, global conventional oil can still continue, but we still expect that it will come around 2020 to a plateau as well, which is of course not good news from a global oil supply point of view.”

Coming from a representative of this particular organization, that is quite a surprising statement. Traditionally, the IEA has downplayed any suggestion that global oil output could peak before 2030. A peak in 2020 suggests that we have a lot less time than most firms and governments have been expecting to transition to a post-oil, post-gasoline, post-jet fuel future.

An early peak in oil output could have an enormous effect on both the development of the global economy and climate change. What effect it will have depends on many factors: three crucial ones being the timing of the peak, the severity of the drop-off in output afterwards, and the investment decisions made by states and firms. If we want to continue to produce enough energy to run a global industrialized society, and we also want to avoid the worst effects of climate change, we need to ensure that renewables (and perhaps nuclear) are the energy sources of the future, and that efficient means of energy storage are developed for vehicles.