Science – Page 109 – a sibilant intake of breath

Solar eruption

The Japanese Hinode satellite, launched in 2006, is meant to study the sun from a sun-synchronous orbit. On December 13th, it got quite a show. Sunspot 930 has released an X-class solar flare: twice as large as the Earth, and sufficiently powerful to make the Aurora visible as far south as Arizona.

The video is available here (MPEG). More information is on this NASA page.

Such flares are one reason why it is dangerous to be heavily reliant upon satellites for either communication or navigation. During periods of extreme ionic disturbance, GPS receivers can give positions that are off by thousands of kilometres. The streams of highly energetic particles produced by such flares eventually reach the Earth and threaten both automated satellites and manned vehicles.

The radiation from solar flares is also one challenge involved in a possible manned mission to Mars; with the kind of timescales involved and the absence of the protection from Earth’s magnetic field, the danger posed by such radiation could be considerable.

Red light

With people banning incandescent lightbulbs and the days finally approaching appropriate summer length, it seems as good a time as any to be thinking about light. On the human retina, there are two major kinds of photoreceptive cells: cones (which identify colour) and rods (which are only sensitive to the overall brightness of light). Because rods are the more sensitive of the two, people actually see in black and white, when it is properly dark.

Like photographic paper, rods are not sensitive to long wavelengths of visible light, over on the red side of the spectrum. This is because the shorter the wavelength of a particular photon, the more energetic it is. Further to that, only light of a sufficiently narrow wavelength can accomplish certain tasks. For instance, only light of a sufficiently narrow wavelength can excite metals so as to produce the photovoltaic effect used in solar cells. Brian Greene has a rather good explanation of this in his book The Elegant Universe: the first half of which is a highly comprehensible primer on twentieth century physics.

The upside of red light not being able to affect rods is that one can be immersed in red light without losing the ability to see in the dark subsequently. This is why submarines are sometimes illuminated with red light – allowing the crew to see more than would otherwise be possible in the event of a power failure – and one reason I am hoping my replacement headlamp will be especially useful. The last one vanished curiously before the Devon trip, earning me a very nasty knock on the head caused by a thick low beam outside. The lost headlamp served admirably during the 2003 New York City blackout, as well as in a great many places besides, The new one, which has a mode in which it produces only red light, will probably be useful during stays in future hostels. It may also provide some interesting lighting possibilities for future photographs; high contrast red and black compositions can be quite compelling.

Reading material

Those who feel that they haven’t been getting their fix of geeky news from this blog recently (I have been too busy to investigate things unrelated to my official studies) may want to have a look at Cocktail Party Physics. Written by Jennifer Ouellette, it seems to include a pleasantly esoteric collection of disciplines and scientific discussions. Recent entries discuss satellites testing General Relativity, computing with bubbles, and the chemical properties of gemstones. The posts I have glanced at are well written, and have a nice personal touch to them.

I will be done the thesis, and back to my old self, by tomorrow night.

Microbiology on display

This is too cool not to link: The Inner Life of the Cell

This short video shows animations of some of the chemical processes that occur inside living cells. I only recognized a handful, but they are all beautiful and surreal. The focus is on the behaviour of lymphocytes in the presence of inflammation.

[Update: 13 December 2007] The links above had become outdated. As of today, they are repaired.

Connections

One thing about studying climate change is that you never know where you will find new information. Have a look at this segment from James Burke’s Connections. He is talking about the Little Ice Age, which began in the 16th century. Much of what he says about adaptation is relevant, in an indirect way, to the kind of climate change being experienced now. I remember being terribly disappointed when his column vanished from the back of Scientific American – my staple reading before shifting to The Economist. Here is another short clip from Burke, also relevant to my thesis project. Here is yet another.

Note that Wikipedia has an entry on the Little Ice Age, the Medieval Warm Period, and the IPCC. It is badly in need of being improved.

Minimum temperatures

Most of the climate change discussion has centred on global mean temperatures, but it is also important to consider minimum temperatures. The degree to which winters are properly cold has important effects: notably, on the distributions of pests and disease. The temperature a species can tolerate serves as a limit to its expansion, so warm winters can help undesirable creatures to spread into new areas. This is akin to how it is important for a course of antibiotics to kill 100% of the target bacteria. If it does not, a fullblown new infection is likely, once the drugs are discontinued.

The ranges of ants and bees have been extending northward in Europe and North America. Likewise, the populations of ticks carrying Lyme Disease and malarial mosquitoes have been shifting northward, along with those carrying Dengue Fever and Japanese encephalitis. This is part of a general trend in which species being displaced by climatic changes (See: Thomas Lovejoy notes). The fact that whole ecosystems do not move northwards and to higher altitudes at the same rate causes further problems, as predation relationships are disrupted.

These kinds of higher level effects are likely to become better understood as further research is carried out. The depth of information has already increased a great deal: the fourth IPCC report, which is in the process of being released, is based upon a review of more than 1,000 academic studies. The Third Assessment Report, in 2001, was based on about 100.

PS. The trio of WordPress sites have been upgraded to version 2.1.3. If you spot any problems, please let me know.

Scientists and remedies: brainstorming

Tonight, I am brainstorming connections between scientists and remedy design. Addressing environmental problem basically seems to revolve around changing the intensity with which an activity is being carried out (ie. fish or cut down trees at the rate of regeneration) or finding substitutes (using solar power instead of natural gas power). Both kinds of solutions involve some critical imputs from scientists. Not surprisingly, my focus here is on types of actions that pertain specifically to my case studies.

I have come up with the following. Does anything else spring to mind?

Technological development

Development of:

Alternative chemicals to replace ones that have been problematic (for instance, CFCs and POPs)
Alternative mechanisms for energy generation, storage, and transmission
Energy-using technologies that are more efficient
Plant varieties that require fewer pesticides
Mechanisms for the disposal or long-term storage of unwanted by-products
Less polluting mechanisms for waste disposal

Predictions

Anticipating the consequences of:

Continuing to behave as we have been
Adopting one or another alternative approach
The combination of our impact upon the world with possible natural changes, such as major volcanic eruptions

Providing information about uncertainty:

How good are our predictions?
If they do fail, in what ways might it occur (what is not included in the models?)
What kinds of uncertainty are out there (ie. magnitude of effects, distribution of effects, etc)

Predictions about technological development:

What will the state of environmentally relevant technologies be in X years?
Is it better to invest in the best technology we have now, or continue research and wait (partly an economic question)

Big ideas about the world

Establish and describe the limits of nature:

Is this a factual or ideological exercise?
The same facts could justify differing views
Some ideologies have elements that can be pretty effectively undermined by science (ie. eugenics)

How should we treat uncertainty?:

Are there categories of risk that it is more ‘rational’ to worry about?
When does it make sense to ‘wait and see’ and when does it make sense to act in a precautionary way?

Naturally, those last few items extend into territory that is not obviously scientific. One big question about the social role of scientists is the extent to which they do or should contribute to such hybrid debates, with both empirical and ethical dimensions. Also, there is the question of whether they do or should do so ‘with their scientist hats on’ or whether they are no different from any other actor, once they have strayed from their area of core competence.

Law and science

Another intersection between science and policy is embodied in a recent report (PDF) from the Science Select Committee of the British Parliament on the relative harmfulness of different legal and illegal drugs. Notably, the survey ranks alcohol and tobacco as being more harmful than illegal drugs including cannabis, LSD, and ecstasy.

Setting aside methodological issues, the survey does reveal some ways in which our response to scientific information is conditioned by pre-existing understandings and practices. Why society feels that it should permit an adult to drink or smoke as much as they choose to (though not in public or before driving) but that it must actively forbid the use of some other substances has no clear logical basis. Any argument that can be used to justify legal tobacco (free individual choice, etc) could be just as easily applied to other substances on the select committee’s list. While scientific and ethical arguments can be made to bolster various positions, it seems that sheer momentum is the main determinant of policy.

I would be willing to guess that some prescription drugs – especially the anti-depressants given ever-more-readily to children and teenagers – would rank quite unfavourably, if subjected to the same type of analysis.

Climate change feedback effects

Starting with an index card full of items to include, I tried to make a map of basic feedbacks relating to climate change. I got this far, then decided that it probably cannot be done in two dimensions, except perhaps on a really massive sheet of paper:

Note: a chemical formula in [square brackets] indicates the concentration of that substance.

Consider, for instance, a single pathway of effects. Agriculture uses fossil fuels, which produce CO2. The CO2 raises global temperature, affecting global cloud cover in an uncertain way. The cloud cover affects temperature, by reflecting more or less solar radiation back into space. It also affects the rate of forest and plankton growth (as does the original increase in CO2).

All told, you need to account for phenomena in the following domains: atmosphere (gas concentrations, cloud effects), hydrosphere (ocean density, temperature, currents), cryosphere (ice and glacier levels, permafrost), and biosphere (plant growth, forest fires). Add to that feedbacks within human behaviours (agriculture and forest burning, for instance) and feedbacks between anthropogenic and non-anthropogenic sources of climate change, such as volcanic eruptions (lithosphere) and changes in orbits and solar output. Doubtless, I have overlooked and forgotten many relevant effects, also.

My hat goes off to the producers of general climate models (GCMs) that have started to incorporate the most important of the linkages shown above. These complex dynamic systems are tricky things, not easily dealt with through the general tendency in science to break questiond down and understand them bit-by-bit.

Oceanic microorganisms

One of the most interesting points repeatedly discussed in Bill Bryson’s A Short History of Nearly Everything is the astonishing variety of microbial life that exists on earth. Regardless of how you arrange your taxonomy, there is far more variety in single-celled life than in the more familiar multicellular variety. What’s more, it seems that single-celled creatures may be more diverse in the ways they carry out essential biological tasks like energy collection, movement, and communication.

One of the more interesting bits of research being done right now is the work of Craig Venter through the Global Ocean Sampling Expedition. Using samples taken from seawater from around the world and ‘scattershot’ techniques of genetic sequencing, some new information about that variety has been uncovered. This one program has tripled the number of genes that have been sequenced by humanity (from three to nine million). For instance, the project discovered a great deal about a class of messenger molecules called kinases. Previously, they were believed to consist of a single family of proteins, used by plants and animals. Now, nineteen new families have been discovered, all in bacteria.

In every age, there is a certain temptation to think we have most of the basic knowledge about how the world works mapped out. Projects like this help to reveal just how much there is left to come to grips with.

PS. Those curious about some of the ongoing debates in biology should have a look at two Wikipedia entries: Kingdom and Taxonomy. Some of that Kingdom-Phylum-Class-Order-Family-Genus-Species stuff we all learned in high school is coming under challenge, at the same time as there is a big schism between those seeking to categorize organisms by similarity in structure and those intent to do so on the basis of tracking genetic progressions.