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Turn of the worm
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Smokescreen From John Chubb There are technical as well as political risks associated with geoengineering approaches to limit the impact of climate change (6 August, p 3). If research shows that predicted temperature rises could be limited by geoengineering, it is likely there will be pressure to go ahead, with a corresponding reduction in pressure to limit emissions. This may be successful in the short term, but stronger and stronger geoengineering will be needed if emissions continue to grow. Life on Earth will become dependent on the continued effectiveness of increasingly potent human interventions. The only acceptable use for geoengineering would be to buy time while we try to cut emissions, not as an alternative to emissions control. Cheltenham, Gloucestershire, UK
Farming vs foraging From Guy Cox Economist Samuel Bowles’s study of the calorific costs of early ways of producing food (30 July, p 26) adds a valuable extra dimension to the debate on the emergence of agriculture. The decrease in physical stature and health in the transition from hunter-gathering to agriculture is well documented, so we must believe it. But present-day evidence contradicts it: compare
Indigenous Australians, who were until recently Stone Agestyle hunter-gatherers, with nearby Papua New Guinea highlanders, who are still Stone Age-style agriculturists, albeit now with metal tools. The latter have a more powerful build and healthier appearance. There are other factors that affect the survival prospects of the two groups, though. Agriculturists typically store food; hunter-gatherers do not. So even if their diet and health is worse, the agriculturists are better able to survive bad times. Another factor is the carrying capacity of the land. Agriculture can support more people per hectare, so in the end greater population density may make it the only option. Sydney, Australia
Imperial confusion From Graham Hodgson In “Mighty rover” (6 August, p 26), NASA’s Class 10,000 conditions for rover assembly were described as containing “fewer than 10,000 particles of 0.5 micrometres or larger… in every cubic foot of air”. Has the loss of its Mars orbiter in 1999 taught NASA nothing about mixing metric and imperial units? Tunbridge Wells, Kent, UK
Turn of the worm From Kathryn Maddison I was intrigued by the use of helminthic parasites to treat autoimmune diseases (6 August, p 6), as some years ago I was infected with hookworm in Vietnam. I was quite ill and treated in hospital on my return to the UK. I have mild asthma which, while not too bad, is noticeable. For about a year after my “worming” I did not need asthma medication at all. My story is anecdotal I know, but it was an
The house owner may not be happy, but their customers certainly should be. Reading, Berkshire, UK
Hot idea?
The editor writes: n There is evidence that helminthic infection, particularly with hookworm, can alleviate asthma. However, some helminths pass through the lungs on the way to the gut and can temporarily worsen asthma or trigger attacks. Roundworm has been found to worsen the condition, for example. The impact of helminths on immune disorders of the respiratory tract is less well studied than on those of the intestines, though.
From Richard Durrant The engineering ideas for cooling subways, particularly the London Underground, did not address the impact of the late afternoon rush hour, when temperatures peak (6 August, p 38). I suggest a modified train sent to the hottest station carrying coolant – tanks of compressed air at about 20 megapascals. The expansion of this air would cool the surroundings and displace hot air from the station. Technology for transporting compressed gas in lightweight containers is viable. The containers could be charged by compressors at a suburban depot at night using cheaper electricity. The heat of compression could be removed by cooling with water. St Albans, Hertfordshire, UK
Reasons to hack
Wright stuff
From Matt Black Alan Hewer’s letter suggests that unlike hackers targeting big companies, no one would be sympathetic to a “burglar claiming to have only broken into your house to point out the inadequacy of your locks” (30 July, p 29). This stands to reason only if one also accepts the inadequacy of Hewer’s analogy. To remedy this, the owner of the house would have to be charged with looking after the address details and house keys of millions of others around the world. What’s more, instead of using those keys to burgle others, the burglar should reveal his actions to embarrass the house owner into improving their security.
From Stephen Durnford As a postscript to Richard Fisher’s discussion of the perils of too much knowledge (30 July, p 39), it was said of the Wright brothers that they achieved heavier-thanair flight because they had not been to university, and so did not know that it could not be done. Saltdean, East Sussex, UK
effect I noticed and appreciated, and one which deserves further investigation. Edinburgh, UK
Letters should be sent to: Letters to the Editor, New Scientist, 84 Theobald’s Road, London WC1X 8NS Fax: +44 (0) 20 7611 1280 Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.
20 August 2011 | NewScientist | 31
Smokescreen From John Chubb There are technical as well as political risks associated with geoengineering approaches to limit the impact of climate change (6 August, p 3). If research shows that predicted temperature rises could be limited by geoengineering, it is likely there will be pressure to go ahead, with a corresponding reduction in pressure to limit emissions. This may be successful in the short term, but stronger and stronger geoengineering will be needed if emissions continue to grow. Life on Earth will become dependent on the continued effectiveness of increasingly potent human interventions. The only acceptable use for geoengineering would be to buy time while we try to cut emissions, not as an alternative to emissions control. Cheltenham, Gloucestershire, UK
Farming vs foraging From Guy Cox Economist Samuel Bowles’s study of the calorific costs of early ways of producing food (30 July, p 26) adds a valuable extra dimension to the debate on the emergence of agriculture. The decrease in physical stature and health in the transition from hunter-gathering to agriculture is well documented, so we must believe it. But present-day evidence contradicts it: compare
Indigenous Australians, who were until recently Stone Agestyle hunter-gatherers, with nearby Papua New Guinea highlanders, who are still Stone Age-style agriculturists, albeit now with metal tools. The latter have a more powerful build and healthier appearance. There are other factors that affect the survival prospects of the two groups, though. Agriculturists typically store food; hunter-gatherers do not. So even if their diet and health is worse, the agriculturists are better able to survive bad times. Another factor is the carrying capacity of the land. Agriculture can support more people per hectare, so in the end greater population density may make it the only option. Sydney, Australia
Imperial confusion From Graham Hodgson In “Mighty rover” (6 August, p 26), NASA’s Class 10,000 conditions for rover assembly were described as containing “fewer than 10,000 particles of 0.5 micrometres or larger… in every cubic foot of air”. Has the loss of its Mars orbiter in 1999 taught NASA nothing about mixing metric and imperial units? Tunbridge Wells, Kent, UK
Turn of the worm From Kathryn Maddison I was intrigued by the use of helminthic parasites to treat autoimmune diseases (6 August, p 6), as some years ago I was infected with hookworm in Vietnam. I was quite ill and treated in hospital on my return to the UK. I have mild asthma which, while not too bad, is noticeable. For about a year after my “worming” I did not need asthma medication at all. My story is anecdotal I know, but it was an
The house owner may not be happy, but their customers certainly should be. Reading, Berkshire, UK
Hot idea?
The editor writes: n There is evidence that helminthic infection, particularly with hookworm, can alleviate asthma. However, some helminths pass through the lungs on the way to the gut and can temporarily worsen asthma or trigger attacks. Roundworm has been found to worsen the condition, for example. The impact of helminths on immune disorders of the respiratory tract is less well studied than on those of the intestines, though.
From Richard Durrant The engineering ideas for cooling subways, particularly the London Underground, did not address the impact of the late afternoon rush hour, when temperatures peak (6 August, p 38). I suggest a modified train sent to the hottest station carrying coolant – tanks of compressed air at about 20 megapascals. The expansion of this air would cool the surroundings and displace hot air from the station. Technology for transporting compressed gas in lightweight containers is viable. The containers could be charged by compressors at a suburban depot at night using cheaper electricity. The heat of compression could be removed by cooling with water. St Albans, Hertfordshire, UK
Reasons to hack
Wright stuff
From Matt Black Alan Hewer’s letter suggests that unlike hackers targeting big companies, no one would be sympathetic to a “burglar claiming to have only broken into your house to point out the inadequacy of your locks” (30 July, p 29). This stands to reason only if one also accepts the inadequacy of Hewer’s analogy. To remedy this, the owner of the house would have to be charged with looking after the address details and house keys of millions of others around the world. What’s more, instead of using those keys to burgle others, the burglar should reveal his actions to embarrass the house owner into improving their security.
From Stephen Durnford As a postscript to Richard Fisher’s discussion of the perils of too much knowledge (30 July, p 39), it was said of the Wright brothers that they achieved heavier-thanair flight because they had not been to university, and so did not know that it could not be done. Saltdean, East Sussex, UK
effect I noticed and appreciated, and one which deserves further investigation. Edinburgh, UK
Letters should be sent to: Letters to the Editor, New Scientist, 84 Theobald’s Road, London WC1X 8NS Fax: +44 (0) 20 7611 1280 Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.
20 August 2011 | NewScientist | 31