Clean and dry
Your article on hand-drying implied that paper towels are more hygienic than air dryers (18 September, p 17). However, the study you reported was not designed to look at how many microbes get left on the skin by different drying techniques, rather to illustrate how residual moisture left through incomplete drying transfers them to other surfaces. There was no attempt to identify species of bacteria removed 鈥� many bacteria found on the skin are harmless and needed to protect the skin. This subject is very much still open to debate.
Importantly, your article did not distinguish between the performances of the three electrical dryers tested. Unlike the two warm-air machines, which evaporate water, the Dyson Airblade produces sheets of filtered air that dry hands completely in 10 seconds, with no rubbing required. And unlike the warm-air hand dryers, the Airblade reduced rather than increased bacterial counts on hands when used as intended.
The report concluded that the short drying time of the Dyson Airblade should encourage more people to dry their hands properly, reducing the spread of infection.
Tutan-come-on
Jo Marchant writes about the ethical issues concerning research on ancient corpses, mentioning that philosopher S酶ren Holm wants people involved in such work to think about whether their endeavours are “motivated by scientific inquiry or simply by curiosity” (11 September, p 17). Holm seems to forget that curiosity is the root of scientific inquiry: after all, we did not know we needed penicillin until we found out what it was useful for.
A knowledge of Tutankhamun’s family history, one of the examples given in the article, could prove important for many reasons. By linking genetic sequencing with such a famous figure, you could actually increase the popularity of science in schools 鈥� something much needed given the flagging numbers of students choosing the subject.
Until we start looking, how can we know what we will find out? Research has already shown what Tutankhamun died of, and what his life was like. His family tree is littered with incestuous relationships, infant deaths and missing persons. Researching the available DNA may provide more information about life in ancient Egypt, and might even inform us about aspects of modern life.
Online solace
Whenever I read an article about the internet, and online gaming in particular, such as Paul Marks’s recent offering (11 September, p 24), it always seems to be about how it can damage our health and social life. There is another side to this debate, however.
I have Asperger’s syndrome, and as a result I prefer spending time on my own to socialising. I also have issues communicating; I find using the telephone particularly difficult but feel more comfortable with email. Playing online games allows me to interact with other people in a way that I feel comfortable with.
While I do spend a lot of my free time online, I have never taken time off work because of gaming, nor do I get withdrawal symptoms if I am away from it for a few days. If my internet access were taken away, I would be far more likely to spend my time reading or pursuing some other solitary activity than going out or socialising.
There are some people who can’t get out easily, or at all. For them, the internet provides a chance that they would not otherwise have to interact with others.
While some people do get unhealthily addicted to the internet, we should remember that there are others who benefit from it, despite spending more time online than would be considered healthy for a “normal” person.
Cholesterol crusher
Donald Fabian expresses confusion at changes over time to the levels of blood cholesterol considered acceptable, and the link between coronary heart disease and high blood cholesterol. In his response, William Neal of West Virginia University states that “mortality from heart disease is influenced by many more factors than blood cholesterol level” (21 August, p 26).
The matter is complex, and one aspect is that the relationship between blood cholesterol and coronary heart disease only exists in societies which consume more omega-6 than omega-3.
The ratio of these fats in the body is directly related to diet. Seafood is the only source of ready-made long-chain omega-3, and omega-6 fats are derived largely from vegetable oils such as sunflower, corn and soya. In recent years, the omega-6 content of the western diet has become more extreme as these vegetable oils have become ubiquitous in processed foods and people h ave been persuaded that these same oils are healthier than saturated fats. Short-chain omega-6 oils can swamp the enzyme system in the body that makes long-chain omega-3s from shorter-chain omega-3 fats in a person’s diet. That exacerbates the problem of insufficient dietary intake.
In the context of the cholesterol debate highlighted in your correspondence, the omega-3/omega-6 imbalance of recent years has magnified the effects of cholesterol. It explains why recommended levels of blood cholesterol have been reduced.
While it is difficult to alter blood cholesterol levels through diet, the omega-3/omega-6 balance is a direct function of diet. The simple solution is to eat more seafood, or take fish oil supplements, and to reduce the consumption of oils containing high levels of omega-6.
Commanding words
Philologists, and others who study the roots of language, are not much taken with the idea of one early human suddenly deciding to develop names for things (4 September, p 30). More appealing is the suggestion that the first spoken words were commands. Those who study the oldest languages have noted that the earliest forms of imperatives are among the most archaic word forms known.
You can just imagine Stone Age men using language in an attempt to control the other hunters in their tribe. Even more beguiling to me is the scene probably taking place back at the cave among women, who might be using language to negotiate ways to help each other.
Shared illusions
I read the “Why your brain flips over visual illusions” article (4 September, p 14), then the piece “Weird water lurks inside giant planets” (4 September, p 15), only to find that the diagram of a planet’s interior exhibited just the kind of perceptual visual switch discussed on the previous page. Sometimes the cutaway section appeared to be a pyramid protruding from the planet, and sometimes it appeared to be concave as intended. What a coincidental juxtaposition.
Hotting things up
Further to your article about the idea that fever may help the body fight disease (31 July, p 42), sweating out a cold was common practice at my military boarding school in the early 1960s.
Life there was harsh enough without the misery of illness, which usually induced some form of inattentiveness that in turn resulted in a disciplinary charge. So the onset of a cold meant borrowing as many army greatcoats as possible and piling them onto the sick person’s bed at night to try to bring about a cure.
It seemed to work, too, though the fact that we were young and fit may have played a part. Even today I double up the bed covers if feeling feverish, though still wonder if it is a case of feeling better because you think you are better.
From John Morton
Does George Mills seriously think, as his letter appears to suggest (11 September, p 30), that malaria can be cured just by wrapping the sufferer in blankets and sitting them in the sun, as he says the Zulus used to do? The reports that there are over 200 million cases of malaria a year, and nearly a million people die of it each year. Most of them are children in Africa. If Mills and presumably the Zulus know how to cure malaria in 24 hours, why on earth don’t they tell everyone?
Pontypridd, Mid Glamorgan, UK
Implosive dice
James Mitchell Crowe writes about the somewhat exciting decay of celluloid materials, mentioning the spontaneous ignition of early film tapes due to the flammable nature of the plastic (19 June, p 42).
The Museum of Jurassic Technology in Culver City, California, devotes a room to the magician Ricky Jay’s collection of decaying celluloid dice. As Jay explains: “These cellulose nitrate dice, the industry standard until the middle of the 20th century (when they were replaced with less flammable cellulose acetate), typically remain stable for decades. Then, in a flash, they can dramatically decompose. The crystallisation begins on the corners and then spreads to the edges.” Evocative images of the progressive decay and implosion are online at .
Perplexing particles
One can be forgiven, I think, for becoming bemused at the number of items in cosmology we have to accept on trust. We have dark energy and dark matter, and many particles for the Large Hadron Collider to discover. Every known particle has, we hope, an elusive supersymmetric partner to find.
Then there is the Higgs particle, the chameleon particle, and now we have the inflaton 鈥� a particle responsible for the inflation of the universe (21 August, p 6). Plenty of discoveries still to be made, then, before we look for the ultimate particle 鈥� the cosmologon.
For the record
鈥� We erroneously attributed to Thomas Frost the statement that sheep and goats cannot interbreed to produce viable offspring unless the embryos are genetically manipulated. The statement should have been attributed to the writer of the letter in which it appeared, Juliet Clutton-Brock (4 September, p 27).
鈥� Nick Ashton is at the University of Manchester, UK, not Southampton as we stated (14 August, p 18).
鈥� We accidentally relocated Denis Dutton to the UK. He actually works at the University of Canterbury in New Zealand (18 September, p 46).
鈥� We misspelled the name of the conservation organisation, WildTrack, in our story on animal identification (18 September, p 20).
鈥� We got Michi Tobler’s name wrong in our article on religious rites and evolution (18 September, p 7).