Shopping shame
You report that women are better than men at finding food stalls (1 September, p 21). The reason may be found in the message emblazoned across girls’ T-shirts in my local Tesco store: “Born to shop”. No wonder we are still struggling to increase numbers of women in science, technology and engineering, when the UK’s largest supermarket cannot find a better aspiration for half our younger population than mindless consumerism. I may have to start my own lines: “Born to save lives”, “Born to end war”, “Born to solve global warming”…
Sweet enough already
The George W. Bush prize for ignoring the elephant in the room must go to the Corn Refiners Association in the US for their statement that corn syrup is “no different from other common sweeteners, such as sugar and honey”, while at the same time acknowledging that one of the primary causes of diabetes is obesity (15 September, p 26). A major driver of obesity in the US must surely be the omnipresence in food of carbohydrate-based sweeteners like corn syrup.
Almost all American food, from bread to fizzy drinks to snacks to burgers, is liberally laced with cheap corn syrup and cheap corn starch to suit the over-sweet American palate. This has been the case for decades. In 1977 I worked on a project to import into the UK a brand-leading, US pie range, and in tests 10 out of 11 of the flavours were rejected outright as disgustingly sweet. There is no sign of change on the horizon: many of my friends in the US complain about how sweet their food is and how hard it is to find less-sweet alternatives.
In a free marketplace, any business that cut the sweetness of its food would lose market share among consumers who are now effectively hooked on sweetened food. The only answer is legislation to label, restrict and reduce the levels of sugar-based sweeteners in food, particularly cheap food aimed at children. If you doubt that it is necessary, study the parallels with smoking, which continued to be accepted for decades after it was widely recognised that it can kill you.
Australian satellites
Australia has several satellites, so why was it not included on your map of satellite-owning nations (8 September, p 45)?
鈥� The map showed countries with five or more satellites, and the database we used listed four for Australia. We have since learned that Australian company then owned five, including one leased to another operator. A sixth was .
Gizmo says relax
The Gizmo column tells us: “The higher the stress, the harder the game, encouraging you to relax” (6 October, p 29). Maybe I’m wrong, but that sounds incredibly… well, stressful. If being barraged by urgent crises is so relaxing, then why do people get stressed at all?
Aerial precision
Stephanie Pain’s piece about Glaisher and Coxwell’s balloon flight was very interesting (22 September, p 54). It was all the more impressive for the accuracy achieved by the (then newfangled) aneroid barometer. Even when unconscious, they apparently measured their maximum altitude as 11,278 metres. It would have been even more impressive in imperial measure: 37,001 feet 3.75 inches. Or were they perhaps “at around 37,000 feet”?
Saccade effects
It is not strictly true that your visual perception mechanism shuts down completely during a rapid eye movement (22 September, p 34). This can easily be confirmed by flicking your eyes across a digital clock running off an alternating-current power supply, whose figures are luminous and flash at 100 or 120 hertz. You may see a line of images of the numbers, spaced out in proportion to the speed of your eye movement.
The same applies to a TV image: flicking your eyes to the right or left produces a succession of lozenge-shaped images, whereas flicking up or down results in a series of images respectively drawn out or squashed. If you flick your eyes down fast enough you can reduce the picture to a single bar, and if you flick your head down at the same time you can even manage to invert the picture, though you have to be very quick. Do not attempt this, however, if anyone is watching you.
Food for dummies
The proposed traffic-light symbols for food packaging (1 September, p 56) simplify the nutritional information they provide to the point where it is all but useless. Shoppers who spend only 9 seconds selecting each food item either know exactly what they want through having bought it before, or never read labels anyway. For those of us who do read labels, vitamin and mineral content and number (or lack) of additives would be of interest.
We are constantly exhorted to eat less salt, sugar and fat. Less than how much? Someone working in a steel foundry would require more salt than an office worker.
Heavy duty
If we are going to redefine the kilogram, can we give it a less misleading name while we’re at it (22 September, p 46)? The fact that the base unit of mass has a “kilo” prefix is a factor-of-a-thousand accident waiting to happen.
More than once I have interpreted a megagram as “a million times the base unit of mass”, which of course works with metres, amps, moles and all the others. The trouble is that a megagram is only a thousand times the base unit of mass. Fortunately, in my case the only damage was to my exam marks.
Tea toll
Your piece on fluoride poisoning from tea is worrying my wife and me (6 October, p 21). We drink a great deal of tea, though very little plain water. I calculate that 11 cups (or 5.5 mugs) could take us to the maximum recommended amount. Our water provider has not told us how much fluoride is added to our water, nor has the tea producer told us how much fluoride is already in the tea.
Should tea packets carry a warning or a maximum number of cups to drink per day?
Noodly joy
The adherents of the Church of The Flying Spaghetti Monster are delighted with your revelation that the four-dimensional universe is composed entirely of pasta (15 September, p 38). Thank you for confirming scientifically for the doubters what we have always known through faith.
More spooky twins
Nick Webb proposes twins whose wallets are different colours as an analogy for quantum entanglement (22 September, p 25). This is absolutely fine for the deterministic view of quantum mechanics, in which initial conditions alone determine the outcome. In deterministic QM, to continue the analogy, the twins’ wallets have initial conditions: that is to say, they are both a fixed colour to begin with. This is the de Broglie interpretation.
In indeterministic QM, the wallets have no discernible fixed colour until you observe one, upon which both wallets immediately take on a colour. The wallets are entangled, as it were, so that if one is red, the other must be green. In this case of the analogy, there is “spooky action at a distance” and faster-than-light interaction. I hesitate to call it communication, as no meaningful information or energy is transferred.
Lifespan limits
Richard Gott calculates that the human race has a 95 per cent probability of lasting between 5100 and 7,800,000 more years (8 September, p 51).
I am disappointed he didn’t take his calculation one step further and go for 98 per cent accuracy. This would have yielded a range of between 2060 and 19,400,000 more years.
From Jan Willem Nienhuys
Richard Gott’s statistical estimate of the time left before humanity expires is nonsense. One can only do statistics if one knows the relevant statistical properties.
The distribution of lifetimes of typical human races is completely unknown, and without this information no conclusion is possible. Even if this distribution were known, we would have to ask: at what time in each possible humanity’s lifetime will someone advance Gott’s pseudoscientific argument?
Waalre, The Netherlands
Population is the key
It is a valuable idea to plot the Human Development Index against the number of planets that would be needed to sustain various lifestyles (6 October, p 10). Indeed, so important is the subject that your graph deserves to be made into a poster.
The graph shows that if, in 2003, the date of the graph, everyone on Earth were to adopt a Cuban lifestyle, then Homo sapiens could manage using 80 per cent of the ecological resources of the planet, and could afford to leave the rest to other life forms. If, as is generally agreed, world population will be about 10 billion by 2070, 1.3 Earths would be needed even if their average lifestyle were constrained to that of Cuba in 2003. What will happen is that some nations will appropriate far more than their fair share, leaving others to misery and diminished life expectancy.
It is also generally agreed that by 2070 oil and gas supplies will have fallen below half the present level, so ecological resources will be needed to provide renewable energy. We have already seen the writing on the wall, as the use of food crops to make biofuels has resulted in higher food prices.
Rather than counting planets, it is more useful to think in terms of the population that could be sustained on the one planet we have. Inverting your figures, it is clear that for everyone to enjoy western European lifestyles, the world population needs to be about 2 billion.
Transplant hope
I have been reading of stem cell research with regard to heart attack recovery and the treatment of lung disease (for example, 4 August, p 17 and 29 September, p 12). It occurs to me that this therapy might also be usefully applied as a long-term anti-rejection treatment for organ transplant patients.
When an organ is donated for transplant it slowly begins to deteriorate as cells die, before it is transplanted into a recipient. This could be exploited after a successful transplant by repairing any damage with stem cells harvested from the recipient. These would then work in conjunction with the donated organ and reduce the patient’s reliance on the treatments currently used to prevent rejection. Is there any reason why this wouldn’t work in principle?
Resource restrictions
I must dispute the conclusions reached by David Cohen in his article on “The shocking state of the Earth’s resources” (26 May, p 34). I totally agree that policies and technologies must be implemented urgently to increase the recycling of all commodities, but I must accuse Cohen of naivety and scaremongering in the rest of his article about how much longer our mineral resources might last.
Permit me to make one general comment about the method behind his calculations, and then refer to the prime example in his article, platinum.
The calculation of how long until we run out of various mineral commodities is based on two numbers. The first is annual consumption, which, for most commodities, is reasonably well known. The second is how much is left in the ground as mineral deposits. For almost every element it is almost impossible to even approach an estimate of this.
The figures used by Cohen are taken from US Geological Survey annual reports. These reports refer to “reserves” and “resources”, the definition of which terms vary slightly in different countries. At its simplest, a “reserve” is an occurrence of ore in the ground about which sufficient geological, technical, mining, metallurgical, environmental, social and governmental legislative information has been documented that mining could be initiated “tomorrow” (given a few billion dollars from the stock exchange). “Resources” are more vaguely and broadly defined, but refer to deposits that have been explored (in terms of the parameters listed above) and about which considerable information has been obtained, and for which there is a reasonable possibility that further investigations could realistically develop it into a reserve, given the conditions (especially, price) that exist today.
Beyond this there is a huge amount of information on mineral deposits and occurrences that do not meet these requirements. They do not fall into the above-defined categories, and are excluded from the US Geological Survey official database.
I can inform readers that the US Geological Survey is undertaking a program to keep up to date with information on the lower categories of deposits, but will not publish it. No mining company that has 30 years’ proven reserves, 100 years of resources and lots more known occurrences (see below) is going to spend millions of dollars now upgrading specific deposits to the next category of increasing confidence, because too much can happen between now and when it will want to mine the deposit.
That is why our mineral resources appear relatively meagre. Suppose that the price of a commodity increased by a factor of 2 because of perceived shortages or increased demand. Every exploration and mining company would brush dust off its files about occurrences where the grade was too low, the metallurgy was a bit complicated, it was too far from infrastructure, or the politics of the country was not conducive to major long-term investment to be economic the last time it was explored. Within a very short time, the commodity would be off the “endangered list” 鈥� a “very short time” in the mining industry being 10 to 20 years.
The best example to demonstrate this effect is platinum, and is the one chosen by Cohen. It is the simplest commodity to evaluate because nearly 90 per cent of the world’s supply and reserves lie in the Bushveld complex in South Africa, so we can forget any possible changes in production or new discoveries in the rest of the world in this assessment.
An article published in 2006 in Mining Weekly in South Africa by a leading stock market analyst, Rene Hochreiter, suggested that there were 700 million ounces of reserves and resources of platinum in the Bushveld complex. These data are limited to a potential depth of 2 kilometres or less, as quoted by several mining companies.
However, the South African gold mines currently reach a depth exceeding 4 kilometres. Only relatively minor issues need to be resolved before that depth could become attainable in principle in Bushveld platinum mines. Even now, deeper mining of the gold reefs is being seriously investigated.
Hence, that figure for platinum reserves and resources can easily be doubled in terms of potential deposits. Three layers are currently being mined for platinum, the Merensky reef, the Upper Group 2 chromite and the Platreef. There are several other layers of chromite that contain 1 to 3 grams of platinum per tonne. If the price of platinum (and chromium) increased, these layers could become economic if both products were extracted.
By including all these possibly exploitable deposits, Hochreiter suggested that these exist over 10 billion ounces of platinum in the Bushveld complex. Such potential occurrences of platinum mineralisation makes it almost infinite. Who knows what mining technologies we will be using in 50 years’ time?
The second issue relates to how quickly currently known reserves and resources could be depleted due to increased demand. Cohen states that “the world’s sources of platinum would be exhausted within 15 years”. A diagram accompanying the article shows that the current resources would last for 360 years at current consumption rates. For platinum be consumed in 15 years requires an increase in consumption every year of 39 per cent.
To achieve that increase, in that last single year (2222) the mining companies would have to open up and exploit 28 times as many mines as exist in total at the moment, and produce 100 times as much platinum as this year. Since 1996 the three main platinum-producing companies have been undertaking a vigorous expansion programme, at staggering capital expense. The logistics of creating new mines and production are such that an increase of about 5 per cent per year has been achieved (as reported in the annual Platinum reviews for 1996 to 2007 published by Johnson Matthey in London). At that rate of increase, current reserves and resources would last for about 60 years, even without any addition to the resource base, which geologists in South Africa know exist.
Let me boldly suggest that vehicle manufacturers continue developing platinum-based catalysts that will reduce the rate of pollution of our atmosphere, and that the fuel cell technologists strenuously develop the energy storage and production systems (which need platinum) that will ameliorate our rate of consumption of other primary energy forms. We do not live in a perfect World, but platinum can help to delay the predicted devastating impacts that humankind is apparently instigating with our consumption of raw materials.
How open access?
Open-access publishing as preached by Jim Giles may be great for readers (22 September, p 22). It would make my life easier. But as editor of a peer-reviewed, free-standing, archaeological journal, I know that almost none of the students and researchers I publish could afford to pay the $1000 needed.
For one thing, the Australian Research Council, our major funding body, forbids this use of its money. Open-access publishing will clearly discriminate against most humanities and social-science researchers everywhere, and against all researchers in poorer countries, just as much as the present practices do although in different ways.
Different research funders have different takes on this. Several in the UK, including the Wellcome Trust, have a separate funding pot to pay for open-access publishing. If your funder does not, the model is indeed a problem. I think more will make the option available in the future. Several open access publishers waive fees for developing world scientists.
For the record
鈥� The map “Next to go” in the article on the Yangtze river dolphin showed only 3000 Hector’s dolphins left around New Zealand (15 September, p 50). This estimate was based on small-boat surveys. More recent surveys from a 15-metre boat and from the air produce estimates of about 7000 for the South Island and 111 for the North Island population, known as Maui’s dolphin. There has been no real increase in numbers: indicates that the actual populations are declining.