Barrage debate
It is true that decarbonising the world’s economies will require some tough choices, but perhaps not quite as tough as Fred Pearce suggests in his article on the implications of a Severn barrage (18 April, p 32).
A report published by , and with less harm to wildlife.
There are other methods of power generation, too, such as solar power. Less than 1 per cent of the world’s deserts could produce as much electricity as the world is now using; less than 3 per cent could produce the amount of electricity that is equivalent to the world’s total energy needs. It should be possible to protect sensitive areas of desert.
New developments in high-voltage direct-current transmission lines mean that long-distance power cables can be laid underground or underwater without costing much more than overhead lines. They have the advantage of causing less visual intrusion. To this end, the investment company Imera has recently announced a 鈧�4.4 billion plan to begin creating a pan-European transmission grid made up entirely of submarine cables.
Menai Bridge, Anglesey, UK
While I am all for looking after the birds, I am sure that they have survived far worse perturbations of habitat during the last 60 million years than would be caused by a Severn barrage. They will adapt, as ever.
Save the Red List
In their response to your article on the IUCN Red List, Jeff McNeely and others (4 April, p 20) fail to address specific criticisms of the list that are raised in the that sparked your article.
One of these criticisms concerns the threat to the Red List’s credibility when it identifies as endangered some species that are unlikely to disappear. For example, McNeely and his co-writers admit that there are millions of green turtles, yet stand by the “endangered” listing for the species, disregarding a wealth of literature to the contrary, such as the report by Milani Chaloupka and others published last year in Global Ecology and Biogeography ().
The Red List undoubtedly contributes significantly to the conservation of global biodiversity. This makes it all the more important to maintain the scientific credibility of the IUCN and of the Red List’s front-line market product: identification of those species threatened with global extinction.
Showery outlook
Fred Pearce’s excellent article “Keep the planet’s heart pumping” (4 April, p 6), which described how coastal rainforests could cause rainfall to travel inland, stirred a memory from my youth in eastern England.
After the second world war, huge coniferous forests were planted in the Breckland area of Norfolk and Suffolk, replacing what had been sparse bracken, heather and gorse. Local folklore claimed that this forestation resulted in a measurable increase in rainfall downwind of the area, affecting prime agricultural land which previously had typically only 30 centimetres of rain per year. I have never seen scientific substantiation of this, although historical and meteorological records verifying it would support Victor Gorshkov and Anastassia Makarieva’s theory. How good it is to hear a theory that, for once, could enable us to change our habitat for the better.
From Kris Ericksen
While the theory described by Fred Pearce may be a “major driver of atmospheric circulation on Earth”, the pressure drop caused when water vapour turns to water may also be a significant factor in the “billowing shower curtain” problem that has in the past exercised Feedback.
David Schmidt’s “vortex model” (28 July 2001) does not account for the person in the shower breaking up the vortex, nor does it explain why a low-volume hot shower creates more billowing than a high-volume cold shower. Putting warm water into a plastic bottle, shaking it with the lid partially on and then promptly tightening it demonstrates the pressure drop of water vapour condensing. Hotter water gives a greater effect.
Highbury, Wellington, New Zealand
Seems familiar
Your article on d茅j脿 vu prompted me to experience an episode of it myself (28 March, p 28).
A few years ago, I worked at the University of Oxford monitoring the neuron response of primates that performed visual memory tasks. We found that many neurons responded most when a new image was shown. However, there was also a population of neurons that responded most to familiar images. This was not to specific images, as one would expect, but rather to all familiar images (Neural Plasticity, vol 9, p 41, European Journal of Neuroscience, vol 18, p 2037).
The brain area we were looking at was the perirhinal cortex in the temporal lobe, next to the perirhinal cortex mentioned in the article, which works hand in hand with the visual long-term memory system. We concluded that there must be an independent system that associates visual information with a “familiarity” response if the conditions are right.
If this system exists, then it could go awry. When it fails to work, we just call it amnesia. If it works all the time, symptoms of constant d茅j脿 vu can appear.
Reporting science
In his article complaining about media distortion of science, Simon Baron-Cohen says, quite rightly, that “every time the media misreports science, it chips away at the credibility of both enterprises” (28 March, p 26).
But researchers themselves have a part to play in this. To avoid misrepresentation in the media, they must take extreme care to ensure that what they and their press releases say is accurate and clear.
Knowledge gained incrementally is the bedrock of science; no hyperbole is needed. The media, by contrast, want to make every story as sensational as possible. As a result, the public and governments are barraged with reported studies and conclusions that often don’t stand up to scrutiny. Worryingly, these reports can influence policy decisions.
Both sides have a duty to raise their standards. 杏吧原创s must ensure they represent fairly the import of their work, along with its motivations and funding, and the context in which it was done. Similarly, journalists are duty-bound to report dispassionately, check their facts, and avoid sensationalism unless it is genuinely warranted.
Binge culture
Andy Coghlan’s article on controlling alcohol consumption using money as a motivation made me wonder if there could be a link between obesity and drinking (28 March, p 22).
Over-dependence upon foods of high glycaemic load contributes to weight gain, and in some individuals seems to lead to a loss of control in limiting appetite, resulting in subsequent “addictive” overeating. Those affected seem to be drawn to foods with a high sugar and simple carbohydrate content but low nutrient diversity and density.
Most people would probably subscribe to the opinion that economic and sociological factors lie behind the antisocial nature of excessive drinking and “binge” culture. But could components of the modern westernised diet also be partly responsible?
I want that one鈥�
Our tendency not to notice when someone presents us with an item we didn’t choose, rather then one we did, is clearly another example of the limits of human conscious awareness (18 April, p 26).
It would be interesting to understand why in 25 per cent of the trials undertaken by Lars Hall and Petter Johansson the substitution was detected. Did the subjects who spotted the switch have some anomalous cognitive skills or were they just paying more attention?
From David Roffe
My cat Shandy was smarter than most, but even she was not immune to choice blindness. She was partial to cheese, as most cats are, but would carefully sniff it before eating. She would examine the second and third pieces, but by the fourth she would wolf down the offering straight away.
At that point I would offer a pickled onion, which she invariably consumed with relish. Whether her onion breath ever gave her pause (or even paws) for thought I do not know. It eventually did for me, though.
Congleton, Cheshire, UK
Biomark-ears
Paul Marks discusses the possibility of using otoacoustic emissions (OAEs) as a biometric marker that could be used to identify individuals (11 April, p 16).
This is rather hopeful, as OAEs rely on the outer hair cells in the cochlea being in a healthy condition. OAEs are used to assess the hearing of newborns and to detect noise-induced hearing loss in adults. Even the mild sensory hearing loss that is common in people over the age of 50 can weaken OAEs to the point where they are no longer measurable.
In the US, hearing loss may affect 10 to 12 per cent of the population. No one would consider using fingerprints or irises as biomarkers if so many people didn’t have them.
Quantum cash
I was charmed to come across the letter from Fred Ramsey about whether the universe is fundamentally random, which concluded with “I know where my money is” (26 April 2008, p 21).
I wonder if it is still there… or, indeed, anywhere?