29th May 2005
Richard Duckett's illustration to Daniel Johnson's article on chess (June) shows an impossible position. The two kings can never be on adjacent squares.
Robert Pellegrinetti
London NW5
Constitutional order
4th June 2005
You shouldn't believe everything you read on the internet. The US's constitution may be the oldest currently in force, but it certainly wasn't the first (In fact, June). Even England, famously shy of codified constitutions, can claim two older: the 1653 Instrument of Government and, my favourite, the 1657 Humble Petition and Advice.
David Cruickshank
Stockholm
Brentford fans
5th June 2005
It was big of Patrick West (June) to concede that not all Brentford supporters are angels. The bruises my brother received from Brentford fans when my family was attacked by them after the Southampton vs Brentford away leg in London last season were also rather big.
Andrew Hitchcock
Brighton
How to be distressed
23rd June 2005
The letters of April and June are both incorrect as neither the union flag nor an ensign are distress signals when worn upside-down. The internationally recognised distress signals are: a red handheld flare or red parachute flare; rockets or shells throwing red stars fired one at a time at short intervals; orange smoke; an emergency position indicator radio beacon; a "mayday" message sent by radio-telephony; a distress alert from a VHF-DSC radio or a SSB set; a gun or other explosive signal at intervals of about a minute; a square flag with, above or below, a ball; a continuous sounding with any fog-signalling apparatus; raising and lowering outstretched arms; the international code signal of distress indicated by NC (eg code flags N over C); SOS in the morse code by any signalling method; and flames on the vessel (as from a burning tar barrel, oil barrel, and so on).
Roger Hurrell
Llandeilo
Women and science 1
24th May 2005
Reading Natasha Walter's remarks (June) on Steven Pinker's comments about girls with congenital adrenal hyperplasia (overexposure to the male sex hormone, androgen, in the womb) one might gain the impression that Melissa Hines's studies provide little support for Pinker's viewpoint. However, in a paper published in February 2004, Hines writes: "Despite postnatal treatment, girls with CAH show altered play behaviour. They are more likely than other girls to prefer toys that are normally preferred by boys (eg cars) and less likely to prefer toys that are normally preferred by girls (eg dolls). They also show increased preferences for boys as playmates and for boy-typical activities. These differences in play behaviour are seen on questionnaires, in interviews and in direct observation of toy choices. They also are seen when girls with CAH are compared to unaffected female relatives, as well as to controls matched for background factors like age and parental socioeconomic status."
On the specific issue selectively highlighted by Walter, that of such girls' spatial abilities, in a recent debate Pinker has now acknowledged that "research on their spatial abilities is inconclusive." One hopes that Walter will have the grace to acknowledge that there is good evidence to suggest that behavioural differences between boys and girls are by no means entirely socially determined. Unfortunately the impression given by her article is that maintaining her version of feminism precludes dispassionate assessment of the evidence on innate differences in behaviour between the sexes.
Allen Esterson
London W6
Women and science 2
18th May 2005
Natasha Walter's essay complaining that dubious ideas about innate differences between men and women's minds are damaging sex equality might have made a contribution to a good cause. But it ignored two most important facts.
Larry Summers's remarks about differences between male and female aptitude for maths and the "hard" sciences were not just a simple-minded noting that men might have more relevant ability on average, just as women may have greater verbal ability. He referred to the possibility that men and women differ in the likelihood that their abilities will differ greatly from the average. That men are more likely to be geniuses and morons than women, not least in maths, is a commonplace among psychologists and certainly consistent with experience and observation. In terms of the normal distribution to which most human abilities conform, he was simply pointing to women's abilities in some areas having a lower standard deviation from the mean compared with men's.
The other, possibly related, fact is that much recent study of the brain has shown substantial differences in connections and structure between the average male and the average female brain, as well as long-known differences in size.
Would it not be sensible to assume that these physical differences have something to do with function? At least would it not be sensible to refrain from dogma for a few years until we know for sure what it is in the brain that provides mathematical or other genius?
James Guest
Jolimont, Australia
Women and science 3
13th June 2005
Simon Baron-Cohen's findings of sex differences in one-day old babies, cited by Natasha Walter, would be less marked if he had controlled for maturity. On average, the brains of new-born girls are some weeks more developed than their brothers'.
Sebastian Kraemer
Whittington Hospital, London
Translating the Koran
1st June 2005
Roger Hart (Letters, June) would like the Muslim Council of Britain to "publicly state that the Koran contains some historic verses that no longer apply to the modern world." Would he petition the Pope, the Archbishop of Canterbury and the chief rabbi to give a similar disclaimer for the various bloodthirsty and vengeful verses in the Bible?
David Gillespie
Kirkcudbright
Tory futures
13th April 2005
Tim Hames's aim is true (April) but I think he misses the biggest target for the Tories. That opportunity is neoconservatism—the thinking that is driving not only the US government but, arguably, our own too.
Neoconservatives have famously been defined as "liberals mugged by reality" and that is what they are. Nothing better can describe Labour pre-1994—with socialism discredited, free markets triumphant and a seemingly impregnable Tory majority to win over and yet with their commitment to social reform intact.
Neoconservatism is a persuasion, a way of thinking, not a movement. It has allowed ex-leftists in the US to remain true to their social consciences and to accept reality—social reform with economic efficiency, you might say—which, as Tim Hames pointed out, is the idea that drives New Labour. "Tough on crime, tough on the causes of crime" could be a typical neocon slogan. New Labour's ethical foreign policy has coincided with neocon policy in Iraq and probably in Kosovo as well. Labour policy on welfare reform acknowledges US developments in the 1980s and 1990s, pioneered by neoconservatives. Both neocons and New Labour speak in the same tones about their grand "projects."
The simple fact is that only the Soviet politburo (dead), old Labour (deadish) and the Conservative party (maybe terminal) missed the broad neoconservative message. Blair and Bush (both still very much alive) got the idea. Can the Conservative party learn before it is too late?
Michael Booth
Oldham
End of uranium?
12th June 2005
David Fleming's article (June), in which he argues that nuclear power is not feasible because the world is on the point of running out of uranium, stands as a useful compendium of today's anti-nuclear folklore. However, the facts do not support him.
Fleming's two principal challenges to the plausibility of a much expanded nuclear future are carbon dioxide emissions from the fuel cycle and the alleged scarcity of uranium. These are important issues.
Carbon emissions from the nuclear fuel cycle and other means of generating electricity have been well analysed by energy organisations with no bias towards nuclear power. Data shows that the carbon dioxide emissions in the nuclear cycle are well under 5 per cent of those emitted when using black coal to generate the same electricity. Natural gas also produces at lest ten times the emissions of nuclear.
The issue of scarcity of geological resources - in this case uranium - has not received as much attention because it was long assumed that the lessons of the "limits to growth" fiasco of the 1970s had been learned. But recently the claim has been making a comeback. Consider the following:
- There are some 3.5m tonnes of known economic uranium resources, with current usage of around 67,000 tonnes per year. Estimates of all known conventional resources are four times this, though the level of certainty of the balance is less and the cost of recovery is likely higher than for the "known economic" category.
- Such data for most minerals bear little relationship to what is actually in the outer part of the Earth's crust and potentially available for use. They are added to as exploration effort proceeds and are therefore not a realistic indicator of what is actually going to be available long-term.
- Usage of uranium (or anything else) produce price signals that result in exploration; historically, expenditure on exploration for uranium, as for other metals, has correlated well with discovery and the replenishment of known economic resources. Were prices to double from present levels, we could expect, over time, to see about a tenfold increase in measured resources.
An anecdote illustrates the general point: In 1980 the high-profile ecologist Paul Ehrlich rashly bet Julian Simon that because the world was exceeding its carrying capacity, food and commodities would start to run out in the 1980s and prices in real terms would therefore rise. Simon, an economist, said that resources were effectively so abundant that prices, as an agreed reliable indicator of scarcity, would fall in real terms. He invited Ehrlich to nominate a "basket" of commodities to test the claim by. In 1990, Ehrlich paid up - all the prices had fallen.
Beyond the 3.5m tonnes of known economic resources are estimates of all conventional resources - 14.4m tonnes of uranium, which is over 200 years' supply at today's rate of consumption. This still ignores the technological factors mentioned below. It also omits unconventional resources such as phosphate deposits (22m tonnes) and seawater (up to 4,000m), which would cost much more than the present market price to extract.
Gains in knowledge of mineral deposits and advances in the technologies of mineral discovery are highly significant. A good example involves Canada's main uranium discoveries, made in the Athabasca Basin in the 1970s. Then, airborne electromagnetic surveys could be carried out only to 100 metres below the surface. Today such surveys yield useful data down to a kilometre.
It is important to recognise – with any commodity at any time – that one should never expect to see known economic resources of more than a few decades ahead because exploration will only take place if companies are confident of making a financial return. The prospect of return is usually dictated by strong prices flowing from the perception of imminent undersupply. When this happens, there tends to be a strong surge of exploration effort yielding significant new discoveries.
With the uranium exploration now being mobilised in response to high prices, I would expect known economic resources of uranium to double in the next decade. In the last decade alone they have increased more than 50 per cent, even though very little exploration for uranium has been carred out since the early 1980s.
In addition to this geological picture, common to other minerals, used uranium fuel can be recycled to yield an extra 25-30 per cent of energy.
Evolutionary light-water reactor designs, which are all more fuel-efficient than their predecessors, will be the mainstay of nuclear programs over the next decade. However, reactors built after 2030 are likely to follow a design that makes them even more efficient.
More significantly, some advanced reactor designs are fast-neutron types, which can utilise the U-238 component of natural uranium (as well as the 1.2m tonnes of depleted uranium now stockpiled). When such designs are run as "breeder reactors" – with the specific purpose of converting non-fissile U-238 to fissile plutonium – they offer the prospect of multiplying uranium resources some fifty-fold and thereby extending them into a very far distant future. Contrary to Fleming's assertion, the technology is well proven, with some 300 reactor-years of experience. Although not yet economic, breeder reactors are already firmly part of the energy plans of such nations as Russia, Japan and India.
Then there is thorium, an element which is even more abundant in the Earth's crust than uranium, and constitutes an additional source of nuclear fuel. Although thorium is not fissile, it is "fertile" – like U-238 being capable of being converted into a fissile isotope, in this case U-233. The technologies for making this conversion and thus utilising abundant thorium are well advanced in India.
Fleming says Storm van Leeuwen & Smith are doing "almost the whole of the relevant work" on energy analysis relating to nuclear power. An appendix to the WNA's Energy Analysis paper shows the erroneous basis of their assertions concerning uranium mining and the energy effectiveness of this - energy costs here are now very well quantified. Also they give no consideration to relatively new technologies, such as "in-situ leaching," which are more efficient than traditional mining methods in terms of both cost and energy use.
The Storm van Leeuwen & Smith papers and their background information represent an interesting attempt to grapple with a complex subject but depend on many speculative figures to put the case that nuclear energy incurs substantial energy debts and gives rise to minimal net energy outputs considered on a lifetime basis. Recent life cycle assessment (LCA) and similar studies show figures around ten times lower for key capital and waste-related energy demands.
Finally, it should be pointed out that, even on the basis of their erroneous assumptions and using their inaccurate figures, Storm van Leeuwen & Smith still are forced to conclude that nuclear power plants produce less CO2 than fossil-fuelled plants, although in their view "the difference is not large." Others might see a 20 to 50-fold difference between nuclear and gas or coal as significant.
These matters and some carbon dioxide emission data are presented more fully here: http://www.world-nuclear.org/info/inf11.htm
Turning to the earlier brief objections to nuclear power asserted by Fleming:
- Nuclear power is economic in most parts of the world, and becoming more so. That issue relates to decisions for investors in power capacity anyway.
- It is environmentally clean, and its wastes are contained and managed rather than becoming environmental problems. This is costed into the power.
- Civil nuclear power does not produce materials usable for nuclear weapons, and its use enables more rather than less control of proliferation.
- It is very safe, and some 12,000 reactor-years of civil experience show no uncontrolled problems with any reactor licensable in most of the world.
Waste management is fundamentally a question of perspective. In Europe, for instance, radioactive wastes comprise about one per cent of all toxic industrial wastes. There have been no problems from storage, handling and transport of civil nuclear wastes in 50 years. The average petrol tanker on UK roads is more of a public hazard than nuclear wastes in transit anywhere in the world. For long-term storage and disposal, a strong scientific consensus favours deep geological repositories. The Finnish, Swedish, American and French governments are taking a lead in moving to construct such facilities.
Internationally, the nuclear renaissance is gathering momentum. At present, 30 nations representing two thirds of humanity use some 440 nuclear reactors to produce 16 per cent of global electricity. More are being built in ten countries because they make economic sense. And more high-profile environmentalists are supporting this, on the grounds that the risks are modest compared with any alternative, particularly the threat of climate change.
Ian Hore-Lacy
World Nuclear Association
