Talking trees
I was fascinated by the idea that trees may communicate by differences in electrical potential (New 杏吧原创, Science, 13 May). How large are these voltages and what power potential do they have?
Perhaps, by selective breeding to enhance the feature, we could have a plantation of trees all chatting away and making a useful contribution to the electricity grid. A power station that also cleans the air and makes oxygen 鈥� it doesn’t get any better than that.
Secretary says
There is no need for Nick Hopwood and Lesley Hall to debate the view of Marie Stopes (Review, 22 April and Letters, 20 May). They can simply ask my aunt, Judith Ross. She was personal secretary to Marie Stopes from about 1929 until she married in 1947. There is probably no one alive today with a better personal knowledge of Stopes’s views. Although she is now approaching 90 her recollections are quite clear.
In answer to the question at issue, Stopes had very strong views about improving the quality of the race by breeding from the best. Her views even extended to her close family. She was certainly of the opinion that inferior people should not breed.
Correction
This is getting silly, but 鈥� in our correction about Jay Pasachoff’s address on 29 April, Pasachoff’s name was incorrectly spelt Pasachov.
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Radio riddles
As usual, the crucial date in establishing Gugliemo Marconi’s priority in the invention of radio is set at 2 June 1896, the date of his provisional patent (Forum, 20 May). For Aleksandr Popov, we are offered the highly contentious date of his sending the words “Heinrich Hertz” in Morse code on 24 March 1896 鈥� a date conveniently “remembered” and tediously readjusted some 30 years after the event.
Like should be compared with like. If a merely remembered event is to be used for Popov, why not also for Marconi? His Italian years, as briefly described by Susan Aldridge, were well remembered without a delay of 30 years.
But, more to the point, Marconi’s documented claims do not commence on 2 June 1896. Under a slightly different title, his patent was first filed as early as 5 March 1896 and the title still survives as a journal entry. Marconi later acquired a letter of introduction to William Preece, Chief Engineer at the Post Office. This letter was signed by A. A. Campbell Swinton and is dated 30 March 1895. It clearly refers to Marconi’s system of telegraphy without wires, its use of Hertzian waves and its dependence on Oliver Lodge’s coherer. These authentic records have just as much historical importance as the official date of the provisional patent.
Aldridge’s lively summary of the Soviet attempt to rewrite the history of wireless telegraphy reminds us how political ideology misused a good scientist. Popov’s role is quite clear. He devised the first successful fully automatic coherer receiver in July 1895 and used it as a storm indicator. Because his “transmitter” consisted of lightning flashes some miles distant, he mistakenly assumed that much more energetic transmitters than those introduced by Hertz would be required for wireless telegraphy over similar distances. He and Oliver Lodge delayed applying their considerable knowledge and understanding to wireless telegraphy, thus allowing Marconi the privilege of doing so.
The world’s greatest injustice has been endowed upon Nikola Tesla (1856-1943) and I believe it is time history corrected this wrong.
Tesla was the true inventive genius of modern times whose rightful place as the inventor of the AC-related electrical components and radio should be justly recognised.
Concerning the AC current, Tesla’s 40 patents (covering his AC motors awarded in 1891) revolutionised the industry; he eventually won his battle with Edison (who favoured DC) to install AC as the current of choice. Tesla’s AC motors became the industry standard and helped electrical giants such as Westinghouse (George Westinghouse, its founder, virtually pleaded with Tesla to sell his AC patents to him cheaply lest his company went broke) and General Electric (Edison’s company 鈥� who fought a bitter campaign against Tesla) become as successful as they have been.
Concerning radio, the US Supreme Court ruled in 1943 that Tesla’s patent No 645 576 (applied for on 2 September 1897 and allowed 20 March 1990) anticipated Marconi’s radio patent and thus accepted Tesla as the true inventor of radio.
Furthermore, Tesla fully described radio in a 1893 lecture, three years before Marconi’s arrival in England. This lecture was translated into many languages and Marconi’s denial of ever reading it was branded absurd by the US Patent Examiner.
Tesla thus got the better of his two adversaries, who subsequently became household names by utilising his inventions commercially. His name has been wiped from history’s books by errors committed in writing and vendettas by vested interests that have gone uncorrected. Such genius eclipses the combined talents of Edison and Marconi and anyone who respects the truth and not “accepted” history should fight for Tesla’s place in history.
Marconi was not the inventor of radio: the first radio transmission was made by Sir Oliver Lodge, an Englishman.
This was a broadcast of Morse code made from the British Association in Oxford on 14 August 1894. A spark gap transmitter situated in the Clarendon Laboratory sent a signal to the Oxford museum about 60 yards away.
In 1896 Sir Oliver Lodge made the first public radio transmission from Lewis’s department store, to the clock tower of the Victoria Building in Liverpool University.
Aldridge contended that Russian physicist Aleksandr Popov’s claims to have demonstrated radio communication rivalled those of Marconi. In fact, the main contender at the time was another scientist who suddenly dropped out of the race and went on to achieve immortal fame in another field.
In 1895, a young New Zealand physics student named Ernest Rutherford arrived at the Cavendish Laboratory in Cambridge. In New Zealand Rutherford had experimented with radio telegraphy. He brought his transmitter to Britain and continued his work, transmitting signals over half a mile 鈥� a world record at the time.
However in January 1896, on learning of R枚ntgen’s discovery of X-rays, the Cavendish Laboratory plunged into this branch of research. Rutherford, who appeared to take the abrupt switch in research topic in his stride, went on to earn the Nobel chemistry prize in 1908 for his work on radio-activity. The following year Marconi shared the physics prize for his work on radio telegraphy.
Fossil crime
In the last 30 years we have seen a phenomenal increase in rock and fossil collecting, to the extent that the hobby has become commercially viable (Thistle Diary, 13 May). Dealers all over the world regularly issue lists of fossils and their prices, just like the fine-art dealers. The problem is that, as soon as a pound sign appeared in the equation, the nature of rock and fossil collecting changed and the criminal element began to move in. I have seen fossils offered for sale, at values sometimes up to five figures, and listed as collected from recognised sites of special scientific interest.
The problem with treating fossils in the same way as works of art is that they are not obviously in the same category as a painting by Munch or a sculpture like The Three Graces. A fossil like Westlothiana would be, to a customs official, a very insignificant-looking bit of rock. Even experts might have difficulty in recognising it as an amniote, rather than a less valuable amphibian.
The problem has, in my opinion, to be tackled locally at the SSSIs. If this is to be effective then the successors to the now-fragmented Nature Conservancy Council must be given the means to police the sites. Sadly the political will to tackle the problem appears to be lacking.
Focus on myopia
Jonathan Beard is right in saying that nobody knows why children become myopic (This Week, 13 May), but it is by no means clear that “years of focusing on close work 鈥� reading, for example 鈥� causes the majority of children to become at least slightly myopic by the time they are 10”.
The onset of myopia is more likely to be associated with a genetic predisposition, and also with the spurt of growth at puberty, particularly when there is a relative deficiency of protein in the diet. This was shown by the work of Peter Gardiner which was published in The Lancet (1954 and 1958) and in the British Journal of Ophthalmology (1960 and 1967).
Spectacles are most important both to efficiency and to general health in established myopia, but they do not alter the length of the eyeball or its refraction.
Job prospects
Following on from Rachel Allen (Letters, 22 April) and your anonymous correspondent on employment for scientists and engineers (Letters, 13 May): I don’t like to depress and further disillusion younger job seekers, but I’m afraid work experience, even in the commercial world, is not going to greatly enhance their prospects for employment.
In addition to what I consider a reasonably impressive academic record, I have a further 12 years experience in the commercial world, including 4 years in the US. Since being made redundant some 14 months ago I have contacted approximately 40 employment consultants specialising in recruiting scientists, made some 70 speculative job applications, replied to 20 job advertisements, and attended 12 interviews.
Experience and knowledge of my particular market sector mean this effort has been well targeted, and I have not been restrictive or demanding in salary, the type, or location of job. I have been conspicuously unsuccessful in obtaining employment, and am now starting my own business.
I too do not believe that there is a simple shortage of scientists and engineers, and make the following observations:
I was a commercial exhibitor at the Institute of Physics conference and exhibition in Brighton in 1993. The greatest proportion of visitors to our stand were scientists, mainly physicists, seeking employment. There are a lot of skilled, experienced and out-of-work scientists.
Government policies, particularly during the Thatcher years, have resulted in the virtual disappearance of many sectors of manufacturing industry. The increasing dominance of the accountancy viewpoint in management, demanding profit at the end of the current financial year, has led to many of the remaining companies turning away from long-term research and development.
Many companies do recognise the skills of scientists, and engineers, but they do not want them for scientific and engineering jobs. The increasing importance of an analytical approach to business, the spread of information technology, and the dominance of PCs, spreadsheets and databases in every area of business mean that a BSc is almost a basic qualification. Pity the non-science graduate, who must be in an even worse position.
The job market for scientists and engineers is not simple; a look through New 杏吧原创’s appointments section shows that there are jobs out there, but only in certain sectors. Over the last few years, pharmaceuticals and software engineering have been particularly prominent. However, if you do not have the qualifications for the currently fashionable market sector, you have a problem.
Experience equates with age. I suspect that my 40 years of age and 12 years’ work experience is actually seen as a disadvantage. Somebody in their late twenties, with two or three years experience is much more attractive to prospective employers, not least because they can be paid less.
The shortage of engineers and scientists is surely a question of field and speciality. As an example:
I am currently finishing off a prison sentence, of which I have served 6 years and 8 months. At the start of this jail term I knew nothing of computing or IT. For the first four years of this sentence I studied computer engineering and artificial intelligence. Now, over 20 national and international computer-related companies sponsor and/or assist me. Yet, I am an ex-gunman serving a lengthy jail term.
The point that I am trying to get across is that anything is possible with perseverance. It has not all been uphill for me; at the start it was really difficult getting those companies, that now help me with my ability in computer science, to forget my past. I am currently doing a computer degree with the Open University as well as a BSc computer degree with De Monfort University in Leicester.
In October of 1994 the prison department released me for a day to attend an international conference at the City of London University to present a paper on the “Teaching of information technology to those in prison”. I research into AI and neural network applications, branching into robotics, and correspond regularly with scientists from Canada to Germany. Every prison that I now get moved to has me employed to configure and repair their PCs, giving me a limited form of work experience and the opportunity of working with up-to-date technology.
Upon release in February 1997, I know that I will get a job in the computer sector regardless of my violent past; two companies have already offered me employment. If I can make a good career while in jail, then students should not be disheartened on the outside if things seem difficult. They have to persevere, always try a different approach and make the most of the facilities that are around them. In this day and age it is not only what you know, but who you know that will help.
Moral bombs
It seems to me that John Noble is pretty naive (Letters, 27 May). When I was told in 1939 to work on the chemistry of uranium as my contribution to the war effort, it was obvious enough that if the Nazis were to win the race to develop the atomic bomb, life for me and millions like me would be intolerable even if we survived.
Noble should take comfort from the fact that when the war was over so many scientists used their freedom in order to pursue humanitarian ends.
It is governments, far more than scientists, who insist on the development of weapons of destruction; it should be the responsibility largely of governments to prevent their use.
Troubled waters
I should like to correct the impression that I agree with Fred Pearce’s view in his article on the effects of North Sea drilling operations (This Week, 6 May), which comes across by the way in which I am quoted in the article.
The oil content of discharged cuttings has always been the b锚te noir of the offshore oil industry, yet there is very little evidence that it is the oil in cuttings discharge that has a major effect on the seabed fauna, except in the immediate vicinity of a production platform. In the early 1980s the use of diesel oil in drilling muds was banned in favour of low aromatic base-oils on the evidence of laboratory toxicity tests.
The switch to so-called low toxicity drilling muds seemed to make no difference, the main effect on the environment, as with diesel, being one of impact by organic enrichment. It seems in the 1990s we are going to go through the same exercise with the non oil-based muds replacing low toxicity oil-based muds and perhaps miss more important issues.
There can be little doubt that in some areas of the North Sea, “background” levels of hydro-carbons are rising, as published by myself in 1992 with the Scottish Office Agriculture and Fisheries Department. What little information we have, and this is where the lack of general access to statutory British monitoring reports has been regrettable, is that the oil responsible may not be derived from cuttings discharge at all. Some of our preliminary studies have indicated the fingerprints of crude oil associated with these background increases.
How serious such an increase in hydrocarbon contamination would be is open to question. Weathered oil is not particularly toxic to marine life. According to Pearce’s article it is claimed that the burrowing brittle star Amphiura filiformis, numbers have been reduced from 100 per square metre to zero within 2 kilometres of production platforms, with serious implications to North Sea fisheries, including cod stocks. Yet recently we found densities of up to 50 per square metre in an offshore area of sea-bed affected by the Braer spill and containing 10000 to 20000 parts per million of hydrocarbon residues. This is at least 100 times higher than might be expected 1 or 2 kilometres from any production platform, certainly in the British sector.
It is extremely unlikely that commercially important fish stocks are threatened by the offshore oil industry, indeed the presence of an installation is more likely to have a positive effect by providing protection for fish within its shipping exclusion zone.
It is clearly time for government and industry to look towards funding more detailed research into the wider issues, if only to prevent the sort of alarmist speculation that seems to bedevil the oil industry.
Minding your peas
According to “Let’s hear it for the pea” (29 April) the cultivation of the pulse pigeon pea “can improve the land”. The operative word here is “can”, which needs to be put into perspective.
It is generally believed that wherever a legume is grown, the soil nitrogen (N) content will be increased. This belief is justified for pastures that incorporate effectively N2-fixing legumes, because most of the N contained in the above-ground part of the plants that are removed by the grazing animals is returned to the soil after ingestion and excretion. However, the more this N is removed from the soil/legume system the less likely it becomes that the soil’s N status will be improved.
In the case of the pigeon pea, if it is harvested as a green vegetable, all above-ground N is removed, leading to soil N depletion. Well-growing pulses such as pigeon pea will fix 100 to 150 kilograms of N ha鈭�1 per crop. When the pods, with a yield of 3000 kg ha鈭�1 and a protein content of 28 per cent, are harvested, then 134 kg N ha鈭�1 will be removed. In that case, there is likely to be neither gain nor loss of soil N.
Yet, it has very often been found that non-leguminous crops such as millet will grow exceptionally well after a pulse crop. My own field experiments have shown conclusively that this is in most cases due to the generation of nitrate that originated from the topsoil N. During heavy rainfall periods, this nitrate can be leached to the sub-soil out of reach of many root systems. This occurs especially where the pulses are grown in roots, with the inter-row areas leaving the soil free of roots during the early part of growth.
Of course, when the stems are also used, for example for fuel or basket making, more N is removed from the soil/plant system, leading to further soil N depletion.
More maggots
Your correspondents (Letters, 3 June) are right to criticise Feedback’s dismissal of Alexander Flemming’s belief in the benefits of using maggots in healing wounds (13 May).
During the successful first ascent of Annapurna in 1950, Maurice Hertzog, the leader of the expedition, together with other members, suffered very severe frostbite. After a horrendous journey back to “civilisation” they arrived in Delhi. When Oudot the Medical Officer “took off my [Hertzog’s] dressings he found that my foot was harbouring a lot of wriggling maggots. At the approach of the surgeon’s tweezers, they withdrew into their holes. By the time we reached Paris these maggots had grown huge, and there was quite a half-a-pound of them. At first I was horrified 鈥� I was being spared nothing! I never got over my horror, in spite of Oudot’s paternal explanation that maggots would clean wounds more effectually than any modern product. They were even, he said, deliberately introduced into certain wounds.”
Hertzog lived to tell his story in the book Annapurna, from which the quotation is taken. He continued to mountaineer, less a number of fingers and toes.