Healthy democracy
The suggestion that high levels of infectious disease inhibit the development of democracy (21 May, p 34) runs counter to social and medical history.
First, the emergence of epidemics and pandemics followed the steady concentration of people into cities, continuing in Britain, for example, up to the era of Victorian slums.
Secondly, before the late 19th century nobody really understood the causes of infectious disease, which are more complex than proximity to an infected person.
Thirdly, the striking improvements in health in many parts of the world are largely due to public health measures, particularly clean water, sanitation, better nutrition and housing, and vaccination.
Introducing these measures required determination, significant resources and above all a willingness to act for the benefit of the whole population, not just for a favoured few.
Not surprisingly, such measures have rarely been popular with despots or oligarchs, but thrive where a more enlightened form of government prevails and takes note of public need.
It is noticeable in the figure on page 36 that Albania and Cuba have a lower prevalence of disease than expected from their “democratisation score”: both have put significant emphasis on public health over several decades.
The most likely scenario is that democracy reduces disease by favouring public health investment, not that poor health inhibits democracy.
Second genesis
The discussion of the probability of the existence of inhabited planets beyond Earth in your “Instant expert” on astrobiology (7 May) falls into the trap of conflating habitability
with inhabited.
It speculates that 1 per cent of small rocky planets are “habitable” and continues as if life has inevitably emerged on them.
A more appropriate way to put this might be that life will emerge on small rocky planets with a probability of 1 per cent. But either way, the statement is completely without foundation, because we do not even know the mechanism that led from non-living chemicals to life on Earth.
Without knowing the process, estimating the odds is meaningless. A small rocky planet may be a necessary condition for life, but it is far from sufficient. It may be the case that life pops up on cue wherever Earth-like conditions prevail, but it may also be that life is a freak phenomenon, with odds against it of trillions upon trillions to one.
Nobody knows. Worse still, nobody even knows how to go about calculating the answer.
The best hope for settling this issue is to find evidence for a second, independent, genesis of life on Earth. That would immediately support the optimistic position of a universe teeming with life.
Life on Mars?
I enjoyed Colin Pillinger’s article (21 May, p 38) about evidence from Martian meteorites that could hint at life on that planet.
However, I was disappointed that he did not mention the controversial results from one of the Mars Viking mission’s biology experiments, which looked for chemical signatures of life in Martian soil samples.
He did mention Viking’s separate measurements of atmospheric gases on that planet, which have allowed us to identify those rare meteorites that originated on Mars, but I and some of my former colleagues at NASA’s Langley Research Center, which managed the mission, still suspect the Viking Lander instruments may have detected the presence of living cells in soil there in 1976.
However, NASA scientists and other researchers concluded that the only positive signal, from an experiment which exposed soil to nutrients labelled with radioactive carbon-14 and which detected radioactive carbon dioxide, could have been caused by an unknown but strong oxidant rather than microscopic life. There are atmospheric models that suggest hydrogen peroxide may be abundant there.
Future missions will hopefully answer the question of life on Mars unambiguously.
Call off the search
Your editorial “Life’s endless possibilities” (14 May, p 3) stated: “We need to spread our search for alien life as imaginatively as we can.” I disagree.
Given that there are more stars in the universe than grains of sand on Earth, or so cosmologists tell us, it is unlikely that terrestrial life is unique. The problem is the huge distances involved.
Suppose intelligent life existed on the other side of the galaxy. If it takes 100,000 years for a radio signal to reach us and a similar amount of time for any reply to reach “them”, conducting any sort of conversation becomes impossible. They may well have ceased to exist by the time the signal reaches us.
This is a burning issue whenever we contemplate reciprocated communication with any but our very closest neighbours in the galaxy, who, it’s safe to say, probably aren’t there anyway since we’ve heard nothing from them.
The millions of dollars spent on the search for extraterrestrial intelligence may or may not produce a positive result. Sure, it would be a momentous discovery from an academic viewpoint, but not one that could justify such expenditure when millions of children on our own planet are dying of disease and starvation.
Code words
I believe the Somerton code (21 May, p 40) was in fact an attempt by a dying man to compose his epitaph, influenced by the Persian verse of The Rubaiyat of Omar Khayyam. This book was found nearby, and much of it is concerned with passing on from one life to the next.
I think that finding it hard to write, he noted the first letter of words, perhaps hoping to write it out fully afterwards. The crossed-out line is a discarded attempt, perhaps initially meant to rhyme, reappearing (modified) in the penultimate line. This has a break between the A and O which I interpret as a poetic line break.
Based on the thoughts and words he was likely to think, the following fits the series of letters that some think is a code:
My Reason Goes On As Brain And Body Die
My Life Is Almost Over, I(this line was crossed out)
My True Being Is My Permanent And Never Ending Thought Processes
My Life Is All But Over, And I Am Quite Content
In Trusting My True Self And My Soul To God Are Bound.
There are possible variations, but I think this may well catch the flavour. I think that the first line was originally “Will reason go on as brain and body die?”, but the W has been changed to an M for a more positive view, and also in the following line.
Wind's weakness
New 杏吧原创 reported that wind turbines are one of “Japan’s energy options in a non-nuclear future” (21 May, p 10). They would “operate a quarter of the time” that is to say with a load factor , just as wind turbines do on our own island, which is also on the edge of a vast ocean, offshore to a vast continent.
Implicit in this averaged output are periods of much lower power output. Power is an instantaneous quantity, if it’s not here now, the lights go out, this instant.
From 17 to 26 December 2010, the UK experienced a large anticyclone that brought widespread calm conditions and low temperatures, with a rise in demand for power. Power output from wind farms hit a low of 0.75 per cent of capacity at around noon on 21 December.
Extrapolating similar conditions to the 33 gigawatts of wind capacity the UK government wants in place by 2020, for which we expect to be paying subsidies, this might only deliver 0.25 gigawatts at peak load times. By then we might be seeing an industrial recovery and roads swarming with electric cars.
Bearing in mind that waves are generated by wind, and solar power diminishes from noon and is zero from sunset to sunrise, what should the Japanese and UK governments build to replace the power stations being closed between now and then?
Rules of thumb
Roman emperors never used the thumbs-down signal to mean the death of the losing combatant in the gladiatorial arena (Feedback, 7 May). As it says in QI: The book of general ignorance, thumbs up signified death (like a drawn sword). Sparing the defeated was a closed fist with the thumb tucked inside (like a sheathed sword).
There was apparently a Latin phrase for it 鈥� pollice compresso favor iudicabatur 鈥� which supposedly translates as “goodwill is decided by the thumb being kept in”.
Mass confusion
The teachers I work with would not teach students that atomic weights were fundamental constants of nature, which is clear from “The periodic turntable” part of your “When science gets it wrong” feature (21 May, p 28).
Students are, however, likely to learn “bad science” by using the word “weight” (a force acting on a mass, dependent on local gravitational field strength, and a vector quantity, measured in newtons) to refer to the mass of an object (a universal scalar quantity measured in kilograms) 鈥� as in, for example, “atomic weight”.
Capturing light
The article “The rush towards renewable oil” (21 May, p 6) could have included estimates of the efficiency with which the photosynthetic alkane-producing microbes convert energy in sunlight into mechanical work.
This is important because, although we must eventually rely on conversion of solar radiation for most of our transportation energy needs, there are many routes to this end, and efficiency is likely to relate to cost and issues such as land use.
It is hard to see how any method that starts with the 0.1 to 3 per cent net efficiency of photosynthesis in producing biomass that yields diesel can compete with a solar cell 鈥� which can manage more efficient conversion of sunlight to electrical power 鈥� The inherent low efficiency of photosynthesis in converting photons to hydrocarbon can only be justified when a high energy-to-mass ratio of the fuel is absolutely essential, as it is when powering aircraft.