For the record
鈥� In our story on deca-BDE flame retardants turning up in the Arctic (12 June, p 10), we mistakenly stated that a survey by WWF said “there was evidence that the chemical caused brain damage in young children”. WWF has asked us to point out that its report does not claim there is any evidence in humans for this.
Expanding software
Thank you Nicholas Negroponte for putting it so eloquently (5 June, p 26). At last! Someone who has noticed that all the great improvements in computing power over the past 20 years have been swallowed 鈥� and more 鈥� by software bloat.
If we went back to the original DOS programs with current technology we would feel like our lumbering 2-gigahertz, 256-megabyte PCs had turned into supercomputers. Plus we wouldn’t have all those useless features that no one asked for and fewer ever use.
Memories to rely on
In your article on the insecurity of personal details typed into PCs, you wrote: “Operating systems such as Windows and Linux have no facility for stopping data being written to the hard drive” (5 June, p 23). This is incorrect. Both Windows and Linux have a special kind of secure, protected memory which cannot be written out to swap files, nor accessed by other processes. All well-written cryptographic processes make use of this facility for storing sensitive data, including passwords.
Recycling emissions
So cool flames can help engineers reduce NOx emissions by lowering the peak combustion temperature in engines (5 June, p 28). To achieve this, engineers usually recirculate a portion of the exhaust gases back into the cylinders.
However, exhaust gas recycling (EGR) can turn out to be bad news. It will recirculate small amounts of soot back into the cylinders, and this will contribute to the build-up of soot throughout the engine. Unless manufacturers install a carbon filter on the EGR connector 鈥� and not many do 鈥� the inlet manifold components of an EGR engine will need regular decarbonisation to work properly. Without this maintenance, emissions will increase.
Venus pioneer
I was surprised that in the article on the Venus transit the pioneering work of Jeremiah Horrocks was not mentioned (5 June, p 32). His observations of a transit of Venus in 1639 are the first recorded, and I understand he was the first to realise that every 113 years there are two transits eight years apart, not just one. This is also missed in the interesting “Histories” article in the same issue (p 52).
In the 1969 edition of the Larousse Encyclopaedia of Astronomy “our” transit was predicted to be on 7 June instead of 8 June. That we are still getting it wrong underlines to my mind the achievement of the young Horrocks 鈥� an amateur who died at the age of 24, and who had no computers to help him.
Dirigible-do
The interview with Hokan Colting, builder of up-to-date dirigibles, reminded me that it is now many years since articles about a renaissance of airships began to appear (22 May, p 44). We have read that for many applications where low speeds could be acceptable, dirigibles constructed using today’s technologies would bring significant advantages over conventional aircraft or ground vehicles. These advantages would mainly be environmental: low fuel consumption, low pollution, low noise and low demand on raw materials.
In addition, simplified take-off and landing infrastructures, and remote control 鈥� which could be made to operate with wide safety margins 鈥� would probably bring cost-advantages too.
Modern dirigibles are said to be especially attractive for transporting bulky objects such as long girders, containers or large prefabricated elements. So it was a little disappointing that the interview made no mention of freight transport. The applications quoted by Colting mostly utilise the high-altitude performance of his airships. I would be interested to know whether the possibility of low-cost, environmentally friendly freight transport is still an aim in the development of modern dirigibles.
Mutant mitochondria
Reading the account of fast-ageing mice (29 May, p 14) left me somewhat puzzled. You reported that accumulated mutations in mitochondria are a potential cause of ageing, and this seems to suggest that mitochondria must somehow be rejuvenated at the point of conception.
I had understood that mitochondria reproduce asexually and independently of the surrounding cell. So my questions would be: “How old is my mitochondrial heritage?” and “Why didn’t I pick up the accumulated mutations of the entire female line back through evolution to the first eukaryote?”
Philip Cohen writes:
鈥� If there were no way to screen out mitochondria with harmful mutations from the germ line we would not be having this correspondence. Cells in ageing organisms have a mixture of functional and dysfunctional mitochondria. During egg formation the number of mitochondria appears to be reduced, creating a strong selection pressure for eggs with a pure population of efficient mitochondria. The process is not well understood. It sometimes seems to break down, resulting in an egg with a mixture of functional and malfunctioning mitochondria, which can result in diseases in the offspring.
Click twice, we sue
The US Patent Office is rapidly becoming the laughing stock of the world. Everyone knows that Xerox and Apple had double-clicking long before Microsoft (12 June, p 23).
For such basic incompetence the head of the patent office should go the same way as CIA director George Tenet.
Water claims
The proposal for a desalination plant on the Mediterranean coast in Israel for the West Bank is not new and was made to the Palestinians some time ago (29 May, p 6).
It is consistent with the agreement by the parties in the region that there is not enough natural water to meet their current and future needs, and that merely dividing the scarce natural resources is not a viable long-term option. This is stated in both the Jordan-Israel peace treaty of 1994 and the 1995 Oslo II agreement between the Palestinian Authority and Israel. In both cases, the parties state that they will jointly develop new sources.
This does not mean that the parties give up claims to the natural resources. The western and north-western basins of the mountain aquifer flow naturally into Israel and have been used continuously by Israel within its borders long before 1967. The Palestinians have a claim to part of that water, and indeed in the 1995 agreement part of that water is allocated to them. They claim more, and that is being discussed in the ongoing bilateral meetings and will be agreed as part of the final peace settlement.
The claim that rainwater that falls in a territory belongs to the people in that territory is not supported by international law, nor by practice within countries or between them. To take just one example, the Nile is fed by areas upstream from Egyptian territory, yet Egypt uses much of this water and will continue to do so.
The 1997 UN Convention lists several criteria for allocation of international waters 鈥� geography and hydrology are but two of them. The convention has only a few specific directives on how to apply and prioritise the criteria: for example, human needs come before any other. The criteria are to be considered and applied according to the specific circumstances. This can also be seen in national water codes.
Wrong number
It’s all very well, bashing the British Medical Journal and Nature for poor statistical practice (5 June, p 19). But in the very same edition you reported that the newly discovered prime 224,036,583-1 was 72 per cent of the size required to claim the $100,000 Electronic Frontier Foundation prize (p 7).
What I think you meant was that it has 72 per cent of the necessary number of digits. The value of the number discovered is in fact about 102,800,000 times smaller than required.
Lower libido
So aspirin and paracetamol lower male libido through “COX inhibitors” (29 May, p 9). I should have thought it was obvious.
Letter
How about a world electoral reform congress in Chad and a world cetacean congress in Wales?
Letter
As well as the world parasitology congress in Laos, I suggest that the world congress on employment be held in Korea.
Poultry in Turkey
Feedback mentions the World Poultry Congress in Turkey and suggests other possibilities (12 June). We could also have a world obesity congress in Hungary, a world ceramics congress in China and a world nut congress in Brazil. Meanwhile, Iceland may be an alternative venue for the world cryogenics congress.
And how about a world Peter Pan congress in the Netherlands?
Was tile thule?
John Gray’s missing island of “Tile” seems to be Thule, a northern island described by the Greek navigator Pytheas in the 4th century BC (5 June, p 31). It has been suggested that it was Norway, Shetland or even Iceland.
Negative calories
So now we know how much pork there really is in salami (12 June, p 31). But how many calories does this 108 per cent pork contain?
In view of the obesity pandemic, I wonder if available calories could be shown on all foods to take account of the net energy produced. For example, celery would have a negative available calorie content based on the well-known fact that it contains fewer calories than are required to chew and digest it, not to mention the calorie content of the excreted remains.
What about cold water, which has zero actual calorie content but which has to be heated up to body temperature, pumped round the circulation a few times, then filtered out through the kidneys? How cold would a glass of cola have to be to achieve a neutral calorie content?
Pharaohphonics
In the late 1960s, you used to reveal the latest research projects of your correspondent Daedalus and his team of intrepid engineers at Dreadco (Daedalus REsearch And Development Corporation). One of Daedalus’s ideas was to map tiny irregularities in the plaster walls of ancient tombs, hoping to retrieve the voices of the plasterers. Presumably their trowels would vibrate like the diaphragm of an old Edison audio-mechanical recording machine, if they happened to be talking as they smoothed the wet plaster.
Back in the 1960s this was just a crazy idea, but the remarkable techniques used to recover early recordings from records and wax cylinders (5 June, p 25) could now be used to found a new branch of archaeology: archaeosonics. Perhaps if Carl Haber and Vitaliy Fadeyev were to take their equipment to the Valley of the Kings, the voices of ancient Egyptians could be heard again after 3000 years or more in plaster.
As to what they were saying, I do not suppose it would have been terribly profound. Something along the lines of, “Do you think Memphis United will get relegated this dry season?”