Elam

The civilization of Elam goes back to at least 3000 BC but lasted several millennia. During my recent trip to Iran I came across the site of an Elamite fortress in central Khuzestan called Cool Farah. From what I understood the guide explained that it had withstood an attack by the Persian king Ashurbanipal, so it existed during the so-called Neo-Elamite II period (c. 770 – 646 BC), although its initial construction could be much older. Here are a few photos of the site as it is today:

Indian and "Arabic" numbers

I just returned from a trip to Iran and Afghanistan, where the people read and write Persian. (In Iran it is called Farsi, the Afghans call it Dari. The two relate to each other like Australian English and US-American English; they are both Persian but have their own characteristics.)
Persian uses the same numerals as Arabic:
However, I discovered that the way numbers are written in Persian and Arabic gives a strong clue to their origin: While Persian, like Arabic, is written from right to left, numbers are written from left to right, even if they occur in a line of text. In other words, they break the flow of reading: The reader arrives at the number from the right, then has to take the number in against the flow of the text, and then revert to right-to-left reading.
It seems clear to me that the reason for this rather strange convention has to be seen in the Indian origin of the Arabian numbers. The Brahmi script, the first script used for Sanskrit, was written from left to right. The Indian number system was first developed in the Brahmi script. When the Muslim scientists learned about the Indian position value number system they introduced it into Arabic in exactly the form as they had found it: They used the Indian numerals and the Indian notation.
While the Persian script remained a mystery for me during the two weeks of my travels, I became quite adept at reading and "translating" Dari numbers, because they follow our way of writing, and in a decimal position value number system you only have to remember ten numerals.

The value of democracy

My discussion of the reasons for the demise of the Soviet Union in lecture 35 may be seen by some as an endorsement of the system of parliamentary democracy. Maybe it is important to emphasize that the principle of democracy, i.e. the exercising of power through the people, can take many forms but that the system of "parliamentary democracy" is not one of them.

Parliamentary democracy is the form of government during the period of fully developed capitalism. It serves the purpose to make the people think that they can exercise power and to hide the fact that the power is and remains in the hands of the ruling class and its agents in parliament. (This does not mean that every parliamentarian works for the benefit of the ruling class, but the system always makes sure that the majority does.) As capitalism matures the political parties become more and more interchangeable, and it becomes more and more difficult to influence future development of society through parliamentary elections.

Experience shows that in a capitalist society real progress does not come from parliaments. Real power by the people is usually exercised though actions outside parliament such as strikes, demonstrations and other forms of direct action. If you need proof look at my other blog, The Woolloomooloo murals.

Minor updates to the text of the lectures

Those who have seen the book version of the web site know that the book follows the text of the lectures. Nevertheless, some minor improvements in the presentation were made during the preparation of the book chapters. As a consequence the book presents some material in a clearer way, and some passages are easier to read in the book than on the web.

In the coming weeks I intend to remedy this and go through the text of the web lectures and associated material to bring them into alignment with the book version. Any changes will be very minor and not change the essence of the text. Amended lectures will be annotated with the date of the last update from now on.

Industrialization in the Soviet Union

In lecture 35 I said: "Supporters of capitalism point towards the collapse of the Soviet Union in 1991 as proof that there is no alternative to capitalism. They ignore that socialism turned the Soviet Union from a backward feudal state into a superpower in a time span of less than 40 years." For today's generation it is indeed difficult to grasp the enormous achievement that the industrialization of the Soviet Union represents. Some figures can provide some background:

In 1923, when the internal enemies of the October Revolution had finally been defeated, "the national income was only one-third of its level in 1913. Industry produced less than one-fifth of the goods, the coal mines yielded only one-tenth, and iron foundries only one-fortieth of their normal output." Many city people were forced to live in the country just to feed themselves: "Russia's cities and towns ... had become so depopulated that in 1921 Moscow had only one half and Petrograd only one third of its former inhabitants." (quotations from David Horowitz: Imperialism and Revolution. London: Allen Lane the Penguin Press, 1969.)

US president Kennedy described the situation in 1963 with these words: "No nation in the historic battle ever suffered more than the Soviet Union in the Second World War. At least 20 million lost their lives. Countless millions of homes and families were burned or sacked. A third of the nation's territory, including two-thirds of its industrial base, were turned into a wasteland - a loss equivalent to the destruction of this country east of Chicago." (quoted in Horowitz, loc. cit.)

The bombing of Hiroshima

In lecture 29 I said about the atomic bomb that was dropped on Hiroshima: "Whether it was instrumental in bringing Japan to surrender is questionable. The Japanese forces were already exhausted, and surrender could not have been delayed much longer. There can, however, be no doubt that the second atomic bomb, dropped on Nagasaki 3 days later, can only be classified as a war crime."

It appears that I was giving the US military the benefit of the doubt, and this quite unjustifiably. Others have been much more damning in their assessment. The nuclear physicist Patrick M. S. Blackett, who in 1947 received the Nobel price in physics for his work on atomic and cosmic-ray physics, "was the first to point out that the Atomic Bombs dropped on Japan fulfilled diplomatic objectives vis-à-vis the U.S.S.R. rather than military objectives which could not be accomplished by other means." (P.M.S. Blackett: Military and Political Consequences of Atomic Energy. London: Turnstile Press, 1948; quoted in David Horowitz: Imperialism and Revolution. London: Allen Lane the Penguin Press, 1969.)

In other words, the sole purpose of the Japanese deaths in Hiroshima and in Nagasaki was to frighten Stalin and establish a position of strength for the Cold War. This would place not just the Nagasaki bomb but both bombs into the category of war crime.

Sonification of tides

To say that this post is relevant to the content of Science, civilization and society is stretching credibility, but it has some entertainment value and is related in some way to the discussion of tides in my blog "The tide predicter of the U.S. Coast and Geodetic Survey" of 25 May. In that post I referred to a web page with an animation of Kelvin's Tide Predicter. The same page has a link to "Tidesounds", where tidal constituents are used to produce "musical scores." You can listen to some examples here: Miami harbour entrance, Daytona Beach, Florida, Cordova, Alaska.

The Tide Predicter page says that "the musical patterns were generated by Stephanie Mason at the University of Minnesota Geometry Center, who wrote C-code to generate predicted tides for these ports, and programmed a NeXT-MIDI interface to generate the corresponding soundtracks." You have to admit that the resulting sounds are more of educational/scientific than musical interest. I asked my son Sebastian, who studies music technology at the University of Adelaide, to produce a bit of sonification of some observational data from one of my field studies. He used data from an oceanographic data buoy that recorded (among other things) wind speed and direction, ocean current and temperature and conductivity at various depths in Thorny Passage near Port Lincoln, South Australia. Here is the result: Southern Ocean sounds.

Seb used the observed wind direction to set the rhythm and the battery voltage to control the loudness; he converted the conductivity at 2.5 m depth into marimba, the temperature at 2.5 m depth into soft organ and the salinity at 2.5 m depth (calculated from temperature and conductivity) into drums. As the water moves in and out through the Passage with the tide its salinity and temperature change slightly, so the up and down of the melody mirrors the tide. The variable speed of the rhythm is produced by the passage of atmospheric fronts that cause sudden changes in wind direction. It does make for more interesting music than just tidal heights from a tide table, don't you think?

You can find Seb's own blog here.

The beginning of marine science

In Lecture 26 I said that "the first of the great deep-sea expeditions was undertaken by the British naval vessel Challenger in 1873 - 1876. This was the beginning of the race for the last territories still available for colonization." This correct but somewhat general statement does not explain why research voyages to other continents had to start with the exploration of the greatest ocean depths. The 20-year birthday volume of Oceanography, the official journal of the international Oceanography Society, has just come out and supplies the answer:
The introduction to the "Summary Report on the Scientific Results of the Voyage of the H.M.S. Challenger" of 1895 says: "The desire to establish telegraphic communication between Europe and America gave the first direct impulse towards systematic exploration of the deep sea." (Briscoe, 2008) It appears that again science - in this instance deep sea science - develops only where there is a need for it.
The same Oceanography volume contains an article that documents in detail how after World War II physical oceanography was driven by the needs of imperialist navies to develop underwater warfare. (Munk and Day, 2008)

References:

Briscoe, M. (2008) Celebrating 20 years of The Oceanography Society. Oceanography 21(3), 12-13.
Munk, W. and D. Day (2008) Glimpses of oceanography in the postwar period. Oceanography 21(3), 14-21.

Science, Civilization and Society: the book is out

As announced earlier, the book version of "Science, Civilization and Society" is now available. It can be ordered by referencing the international book numbers

ISBN-10: 363906593X
ISBN-13: 9783639065930

It can also be ordered online from various sellers. Some are listed at the web site "World Civilizations"; just click on the title of this post. It may be worth comparing prices at other sellers - the steep price was set by the publisher, not by me. As of today the lowest price is only available in Europe, unfortunately.

Lomborg's new discoveries: Old wine in new bottles

In Lecture 35 I discussed Bjørn Lomborg as a practician of partisan science, of willfully deformed science designed to counter criticism of the activities of big business and its government associates. In his book The Sceptical Environmentalist" Lomborg tried (in the words of the advertising text on the book's website at Cambridge University Press) to "challenge widely held beliefs that the environmental situation is getting worse and worse". As "a former member of Greenpeace" he argued that the dangers of global climate change are exaggerated and that "there are more reasons for optimism than pessimism." Cambridge University Press even claims that his book "offers readers a non-partisan stocktaking exercise."

This was in 2001, when Lomborg was on his way to become director of Denmark's national Environmental Assessment Institute, a position he held until 2004. Now the world has moved on, and it has become impossible to close one's eyes before the evidence that global climate change induced by human activity will produce disastrous developments if we do not take correcting action very soon. Lomborg, now Adjunct Professor at Copenhagen Business School, found a new platform in the Copenhagen Consensus Centre. Last year he published Cool It - The Skeptical Environmentalist's Guide to Global Warming, according to his personal website "a groundbreaking book that transforms the debate about global warming by offering a fresh perspective based on human needs as well as environmental concerns."

He continues, talking about himself in third person: "Rather than starting with the most radical procedures, Lomborg argues that we should first focus our resources on more immediate concerns, such as fighting malaria and HIV/AIDS and assuring and maintaining a safe fresh water supply - which can be addressed at a fraction of the cost and save millions of lives within our lifetime."

It is of course befitting for a Professor of Business to see the world exclusively through cost/benefit analysis. It is also not surprising that if you rank today's problems in order of their cost/benefit ratio, supplementing the diet of children in developing countries with vitamin A comes out on top, since some $20 - $30 are returned for every dollar spent, while the return on a dollar spent on greenhouse mitigation could be as low as 90 cents. But what can we conclude from such an exercise? That we should not spend our money on greenhouse mitigation but on vitamin supplements instead?

Lomborg should know - and being a trained academic presumably does know - that cost/benefit analysis does not help us much in the face of crisis if it is not combined with risk analysis. It is also not possible to analyze global problems such as vitamin deficiency in the Third World in isolation. If we ignore greenhouse warming today the children of developing countries will still be worse off in twenty years' time than today, because the entire ecosystem on which their food supply depends will have deteriorated dramatically. But Lomberg's book is not about scientific analysis, it is about selling old wine in new bottles.

The Weekend Australian of 2-3 August quotes Nick Rowley, former climate change adviser to the UK government, as saying that Lomberg is making a fundamental error of logic. "The level of risk we confront is a greater level of risk than virtually any other area. He views these as if they are mutually exclusive; they're not. They're intertwined and you can't see a scenario where under even two degrees of warming the most vulnerable people in the world are not going to be a lot more vulnerable. There are a lot of moral and ethical considerations that need to influence that process as well. It's not just a technical exercise."

As I said in Lecture 35: "It is not the observational evidence that makes Lomborg a partisan scientist, it is the ethical dimension of his science."

Science, Civilizations and Society: the book

This entry supersedes the entry of last August (2007) that anounced the availability of Science, Civilization and Society in book form for pdf download. The pdf version has been withdrawn. It will be replaced by the printed version, to be published before September by VDM Verlag Dr. Müller. More details will be posted as they become available.

Alexander von Humboldt

That Alexander von Humboldt, one of the greatest naturalist and scientific explorers of European history, did not get a mention in my lectures has been on my mind for quite some time. I rationalized this omission by telling myself that a course on the relationship between science and society cannot cover the biographies of all who came to fame during the age of discovery: My table “Major Expeditions 1700 – 1850” in Lecture 25 mentions twenty people (von Humboldt being one of them), but only five of them feature in the index, and short biographies are provided for only four of those.

I have now studied von Humboldt’s biography and have to admit that his low treatment in the context of science and society is not justified. This is not the place to summarize his life, but a few comments on his position in the development of science during the early 19th century are in order.

Alexander von Humboldt (14 September 1769 - 6 May 1859) was born and died in Berlin, the capital of Prussia. After an unremarkable education he became intensely interested in botany, became knowledgeable in mineralogy and meteorology and developed a hunger for exploration. But in the late 18th century exploration went hand in hand with imperial expansion. Prussia was a political power of third rank, and while the Prussian king wanted to boost his Academy of Sciences he did have neither the means nor the inclination to develop a world empire.

Von Humboldt’s career as a scientist vividly demonstrates how scientific progress is shaped by the political constellation of the time. Unable to join an exploration party in his home country, von Humboldt tried to join French exploration efforts. He was invited to join Nicolas Baudin, but political upheaval caused the postponement of Baudin’s voyage. An attempt to go to Egypt with Napoleon Bonaparte also came to nothing. Eventually Spain’s prime minister Mariano de Urquijo supported an application to the Spanish king for a royal permit to visit the Spanish possessions in the Americas.

During the five years 1799 - 1804 von Humboldt and his companion Aimé Bonpland travelled some 9,650 kilometres through South and Central America, walking the ancient Inca roads, canoeing on its rivers and riding across its mountains. Spain’s colonies were in those days only accessible to government officials and Roman Catholic missionaries, and von Humboldt’s and Bonpland’s discoveries in an otherwise closed continent turned into invaluable contributions to the growing knowledge base of botany, geography and earth sciences generally.

On his return from America in 1804 von Humboldt lived in Paris, the centre of science, until in 1827 his financial means were exhausted and he had to return to Berlin, where he received a royal stipend as the tutor of the Crown Prince. He used the last three decades of his life to write Kosmos, a description of the structure of the universe as then known that within a few years was translated into nearly all European languages.

The tide predicter of the U.S. Coast and Geodetic Survey

Robert Merkin of Northampton, Massachusetts, USA, recently sent me a photo of the tide predictor that was in use at the U.S. Coast and Geodetic Survey from 1912 to 1965. It was built by Rollin A. Harris and E. G. Fisher, who modeled it on Lord Kelvin's Tide Predicter, and can handle 37 tidal constituents. It is also known as "Old Brass Brains". Here is Bob Merkin's photo.

Bob also pointed me to a site that offers an animation of Kelvin's Tide Predicter. It shows the workings of the Predicter much clearer than my own description and offers a choice of seven port locations to try it out. Unfortunately it comes under the heading "Fourier Analysis of Ocean Tides".

Fourier Analysis uses multiples of a base period; but the tidal constituents are not multiples of a base period, they are set by the movement of the earth and the moon. Tides are therefore predicted by adding the effect of the various tidal constituents with their known periods. This method is called Harmonic Analysis in oceanography.

In mathematics the term Harmonic Analysis describes an extension of classical Fourier Analysis. When the term Harmonic Analysis is used in the context of tide prediction it does not carry that meaning; it refers to a method that is based on the known periods of the tidal constituents. This has lead to confusion on occasions. Kelvin's Tide Predicter is a very helpful tool to clarify the situation.

Science and the aristocracy

In a study of the history of science it is important to realize that progress in science is not determined by the genius of a few individuals but by the conditions of society. In the age of feudalism only a wealthy aristocrat could afford to pursue scientific interests and go down in history as genius. Ordinary people had little chance to show their potential.

In a footnote to lecture 8 I used the example of Tycho Brahe, the Danish aristocrat turned astronomer. A study of the history of astronomy described his birth in 1546 as "fortunate" for the development of science. I queried that and said: "What honours him and secures his place in the history of science is not his fortunate birth but his decision to turn his back on the idle life of the ordinary nobleman and apply his gifted mind to science." Brahe did not care much about the aristocracy; he married a peasant's daughter and embarked on a career as imperial mathematician and astronomer.

It is instructive to compare Brahe's attitude to science with that of the English nobleman Joseph Banks, the resident naturalist during James Cook's fist expedition into the South Pacific. Banks brought along a second naturalist, a secretary, two artists and four servants, all paid for from his own wealth.

The large amount of work done by Banks and his party in the field of botany and taxonomy was an immense contribution to science. But Banks clearly did not see science as an important part of his life; he saw it more as what Galiliei called the "regal sport" of the ruling class. This became obvious when Cook invited Banks to join his second voyage into the South Pacific on the Resolution. Banks agreed, on the condition that he could increase his party to fifteen, including two musicians to while away the time. He even managed to talk the Navy into adding an extra deck to the ship to accommodate his party.

When the time came to sail the Resolution out of the shipyard one of Cook's lieutenants called her "by far the most unsafe ship I ever saw or heard of." The pilot declared her top-heavy and prone to capsize and refused to even move her off the dock. The ship was restored to her original state and Banks, swearing and sulking, withdrew from the expedition.

The story demonstrates that when it comes to evaluating the role of individuals to science, looking at their contribution to science alone does not produce a balanced assessment. Banks clearly had the capacity and gift to play a much larger role in the history of botany, but he chose the idle life of the aristocracy.

Reference:

Allen, O. E. (1980): The Seafarers, the Pacific Navigators. Time-Life Books, Alexandria, Virginia, 176 pp.

The Catholic Church and the destruction of America's civilizations

Wherever the Spanish conquerors went they were accompanied by friars, whose role was to bring Christianity to the heathens. The Dominican order made missionary activity during the conquest one of its primary undertakings.

There is no doubt that some Dominican friars tried to soften the treatment of the indigenous people by the conquerors and prevented the worst excesses. But there is also no denying that even such intellectual interest as the study of indigenous languages (mainly to enable the Christian gospel to be preached in the local vernacular) was aimed at the final destruction of a "pagan" civilization. Any historical assessment of the role of Christianity has to admit that the muskets and guns of the conquistadors were not the only instruments that brought great civilizations to an end but also the book burnings and destruction of places of worship by the representatives of the Church.

The Convent of San Esteban in Salamanca, Spain, was and remains the centre of the Dominican mission. It features a display of the Dominican role in the conquest of South America. There are exhibits of souvenirs brought back by Dominican missionaries, but one searches in vain for any indication of regret for what happened under their spiritual supervision. Instead, vague and obfuscating texts attempt to conceal their contribution to the destruction of great civilizations.

A book exhibit "San Esteban, Search and Encounter; America, the universalist Dominican vocation" declares: "The world expanded itself, and it became necessary to invent new norms. What was known and understood was no longer sufficient. The search for the truth extended itself to the other side of the ocean." The main inscription on the wall of the Convent is more direct; it concedes that it was not the world that drove the action by expanding itself, admits that actions involved people, and identifies the actors: "The thoughts and the action of the Dominicans of San Esteban in America demonstrate that the battle for the freedom and the dignity of all people is the way to the TRUTH – And the only medium: the WORD." The South American Indians should be thankful for the freedom and dignity they received!

The role of profit in scientific exploration during the "Age of Discovery"

The early European ocean voyages of the Age of Discovery did not always lead to the discovery of unknown lands. Their main objective was to obtain as much profit as could be made. Exploration of new coasts, with the associated benefits for science, was a secondary consideration, performed only to the degree necessary to bring success to the economic purpose of the voyage.

The early Portuguese and Spanish sea captains were true explorers, in the sense that their contract with the crown (four fifth of the profit to the explorer, one fifth to the crown) was based on voyages to unknown destinations and therefore carried great risk. The British crown found it more profitable to raid the Spanish outposts in regions already discovered. It financed Francis Drake, Thomas Cavendish and other "privateers" to sack Spanish settlements and capture Spain's ships.

The profitability of marauding voyages was beyond doubt. When Drake captured a Spanish galleon in 1579 he obtained 13 chests of silver coin, 26 tons of silver bullion, 80 pounds of gold, and uncounted jewellery. Cavendish sacked Puna Island off Peru, slaughtering its Indian inhabitants, in 1587; he returned from his two year marauding voyage with a booty worth 125,000 pounds, nearly half of the Crown's annual revenue. Such adventurism did not contribute much to science.

Carbon targets to manage climate change

This is a follow-up to an earlier posting (see "Prevention of climate change without binding targets?" posted on 12 December 2007) where I said that the only way forward is a strategy based on uniform carbon emission allowances per person. In some countries the principle is making its way into government policy. Here are two figures from the Interim Report to the Commonwealth, State and Territory Governments of Australia (the first draft of the so-called Garnaut Climate Change Review).

The first figure shows the total CO₂ emissions, including those from land-use, for 2004; units are gigatons, the scale is on the left. Squares show per capita emissions, in tons on the right-hand scale. I added the yellow line to the figure; it shows the acceptable per capita emission if we assume that the world has to return to the total emissions it produced in 1990.

The second figure is a sketch (the Garnaut report calls it "a stylised, illustrative scenario") of what has to happen if we want to stabilize the climate. The y-axis gives per capita emissions, the x-axis time, both without units. The figure demonstrates the huge change in lifestyle the USA and Australia have to undergo if they are to reach their per capita targets. The European Union and Japan are under far less pressure but have to reduce their per capital consumption, too. With the numbers adopted by the Garnaut report China has not quite reached the maximum acceptable per capita consumption (which means that my yellow line in the first figure was drawn somewhat too far down on the scale) but will reach it soon, while India is not in such a tight situation.

The Garnaut report was commissioned to form the basis for Australia's climate change policy. Hopefully the Australian government will adopt it in full. Any delay in adoption of the percapita emission principle will cause more damage to the environment.

DDT and "scientific fraud"

In 2004 an article by J. G. Edwards entitled DDT: A Case Study in Scientific Fraud", published shortly after his death, reviewed the history of the ban on DDT by the Environmental Protection Agency (EPA) of the USA. Edwards shows convincingly that most if not all arguments brought forward in support of the ban – negative effects on human health, on birds, on egg shells and others – were not supported by science. He credits Rachel Carson's 1962 book Silent Spring as the trigger for the eventual ban on DDT in 1972 and calls the procedures that led to the ban "scientific fraud".

It is certainly correct that many of Carson's claims about the environmental effects of DDT cannot be substantiated. Carson, who had trained as a biologist but made a career as a nature journalist, was interested in raising public awareness of the deterioration of the environment through industrial products, at a time when such ideas were novel and went against the general belief in scientific progress at all cost. She was successful to such a degree that her book is now widely considered to mark the beginning of the environmental movement. That she argued her case with wild exaggerations and several wrong claims may be understandable for someone who can see the future of a world with an unrestrained chemical industry but is met with hostility wherever she goes, but that does not exonerate her from having employed dishonest means.

Edwards' claim of scientific fraud is another matter. As Edwards reports himself, the DDT hearing of the EPA, which lasted seven months, came to the conclusion that DDT does not pose a threat to human or animal health and recommended to allow its use as a pesticide; but the recommendation was overruled by the EPA Administrator, who had links with an environmental group. There was thus no scientific fraud: Science came to the correct conclusion. The fault lay with the administration, i.e. in the political domain.

Edwards' paper is not completely free from misleading claims. It focuses on DDT use for mosquito control in malaria eradication, describes the early successes with DDT spraying between 1945 and 1960 and says: "After the U.S. ban on DDT, there is a global malaria burden of 300 to 500 million cases and 1 to 2.5 million deaths annually, mostly among young children. Malaria kills an African child every 30 seconds." As Edwards describes it, the ban on DDT can only be seen as a crime against humanity.

This picture is far from the truth for several reasons:

• The use of DDT for malaria control represented a very small proportion of general DDT use of the 1950s and 1960s. Widespread use of DDT in agriculture, while possibly of no harm to humans, can only increase resistance to it and is therefore only a temporary gain, while the quantity of DDT in the environment accumulates. DDT is very persistent in the environment, and the low doses recommended by the EPA science assessment may eventually be exceeded by large amounts.


• The ban on DDT refers only to agricultural use; its use in malaria control has always been permitted. The World Health Organization recommends DDT for indoor spraying, a use that was formally included in the Stockholm Convention on Persistent Organic Pollutants in May 2004, 6 months before Edwards' paper was published. (Indoor spraying – the coverage of walls and ceilings with a thin DDT layer - prevents mosquitoes entering buildings but does not kill them; it acts as a barrier between mosquitoes and humans.)


• The claim that continued use of DDT would have saved millions of lives cannot be verified. Many mosquito populations have developed resistance to DDT (in Sri Lanka, India and many other countries as early as 10 years before DDT was banned). Effective malaria control now requires the use of alternatives such as pyrethroids (synthetic chemical compounds that emulate the natural chemical pyrethrins produced by certain Chrysanthemum flowers and are used in many insect repellents). Ironically, the rapid loss of effectiveness in the 1960s was mainly the result of agricultural DDT spraying, which used much larger quantities than malaria control. This suggests that DDT effectiveness for malaria control could have been maintained much longer if agricultural use of DDT would have been banned 20 years earlier.

References:http://www.blogger.com/img/gl.link.gif

Carson R. (1962): Silent Spring. Houghton Mifflin, Boston, Mass.

Edwards, J. G. (2004): DDT: a case study in scientific fraud. Journal of American Physicians and Surgeons 9 (3), 83-88; available as PDF file.

World Health Organization (2004): WHO position on DDT use in disease vector control under the Stockholm Convention on Persistent Organic Pollutants. WHO/HTM/RBM/2004.53 rev.1, available as PDF file

More information and debate at http://timlambert.org/category/science/ddt