Letter
Sons and mothers
There is no need to invoke evolutionary psychology to explain the apparent fact that poor children in Germany in the 18th and 19th centuries were more likely to die if their paternal grandmother was alive but more likely to survive if their maternal grandmother was alive (14 September, p 17).
The researchers you quote suggest that the paternal grandmother may have suggested to the father that the children in his home were not his, or even encouraged him to impregnate other women, both leading to neglect of the children in his home. I suggest this tells us more about the minds of today’s researchers than about the lives of those families.
In traditional societies it is the duty of sons to support their mothers, and of mothers to help their daughters. An indigent father whose mother was alive might have to choose between supporting her and supporting his child, while an indigent mother might get her mother’s help in supporting her children. These two traditions, taken together, would produce the observed skew in their children’s survival rates. This explanation is far more likely to apply to a whole population than one that invokes suspicions of infidelity on a large scale.
Gimmicky fish
You report that the Taiwanese company Taikong hopes to sell a genetically modified, glow-in-the-dark fish to aquarium enthusiasts worldwide (14 September, p 13).
The position of the Ornamental Aquatic Trade Association is that GM fish have no place in the industry or as a hobby. The OATA represents about 600 businesses in Britain, many supplying tropical fish for aquaria.
I expressed this view when Taikong spoke of their intentions at a trade show and conference in Singapore early last year. My intervention was met with stony silence even though the chair invited a response from the speaker.
The beauty of the range of species available makes GM technology to produce gimmicky fish entirely unnecessary.
Tesla and Tunguska
There is another possible 鈥� if wildly improbable 鈥� cause of the mysterious event at Tunguska in 1908 (7 September, p 14). One of Nikola Tesla’s great projects was the wireless transformation of energy over large distances. He believed that this could be harnessed in war to destroy incoming attacks from over 300 kilometres away.
Tesla built his “death ray” at Wardencliffe on Long Island, and it is a possible that he tested it one night in 1908. The story goes something like this. At the time, Robert Peary was trekking to the North Pole and Tesla asked him to look out for unusual activity. On the evening of 30 June 1908, Tesla aimed his death ray towards the Arctic and turned it on. Tesla then watched the newspapers and sent telegrams to Peary, but heard about nothing unusual in the Arctic.
However, he did hear about the unexplainable event in Tunguska, and was thankful no one was killed, as it was clear to him that his death ray had overshot. He then dismantled his machine, as he felt it was too dangerous to keep it. See for the full story.
For the record
鈥� In our article on blood transfusions (28 September, p 6) we wrote “transmission” instead of “transfusion” in the phrase “transfusion-related acute lung injury, or TRALI”.
Medical milk
So a product derived from milk can treat skin infections (28 September, p 20). Hardly a great surprise, women having been using live yogurt to sooth vaginal thrush for years. I had assumed the “live” properties were the important factor, but perhaps the casein content is also helpful. I wonder if any of the Nestl茅 boffins (if they are men) thought to discuss their research with their wives.
Defended by fat
Your short news article states that slim people who take vigorous exercise are at greater risk of developing motor neuron disease (14 September, p 24).
What about this idea? Since fat cells store toxins, is it possible that in slim people without enough fat cells, environmental toxins might more easily trigger motor neuron disease?
Also, maybe those people who have taken part in sport at high school or college are exposed to more pesticides, herbicides and other chemicals (fertilisers), since many sports fields are regularly doused with such substances?
Living on illusions
There is a worrying tendency to assume that science is the only source of truth and knowledge. John Gray’s essay embodies that school of thought (14 September, p 46).
The philosophy that he argues against is as useful now as it was 2000 years ago. Gray states: “Ever since Socrates, philosophers have aspired to a life based solely on true beliefs. Yet recent research suggests we are programmed to live on illusions.” Gray fails to accept that philosophers attempt either to see through the illusions or show that it is unnecessary to do so. If the human mind were programmed to accept illusions, why would science be better able to show us the truth than philosophy?
Gray later tries to show that science is better at explaining the world than our perceptions. But science is based on perception. A scientist will observe a phenomenon, then devise a theory that states that the world is round (or whatever). Without any basis for the theory in perception, it is nothing more than speculation, no more valid than the a priori metaphysical theories of Descartes which Hume took apart so well.
Finally, it seems to me that when Gray criticises the self, he fails to realise that Hume’s “bundle of perceptions” can be seen as a kind of “self”. This is because the perceptions belong to only one “bundle” and not to any others.
Energy gains
The letter attacking a “nuclear future” prompted me to suggest an alternative approach to comparing the various energy sources available (14 September, p 26). Perhaps we should think of power stations, wind farms, solar cells and so on as energy amplifiers, whose “gain” is the ratio of the sum of energy output during the lifetime of the station to the total energy input in building and maintaining them.
All power sources require significant energy input before you get any useful output 鈥� clearly, even power from wind turbines is not free. Energy is invested in the production of steel and other building materials, and routine servicing and eventual dismantling must be included. The energy required to build, fuel and maintain a nuclear power station, then decommission, process and safely store spent fuel must be colossal.
It would be interesting to compare the “gain” of these various energy amplifiers, and to note the break-even time, that is, the time taken to generate the same amount of energy as was initially used in construction.
You won't wake up
I am surprised that, leg-pulling aside, New 杏吧原创 has allowed itself to be associated with the “science” of cryonics, based as it is on a false interpretation of current cryogenics and its medical applications (Cover, 21 September).
To seek immortality through whole body freezing in liquid nitrogen after death is a science-fiction fantasy; it cannot be realised in the foreseeable future for several reasons.
The difference between successful cryopreservation and failure lies with size and achievable cooling rates. A single cell survives freezing if it cools so fast that the entire cell freezes at once. Such cooling must take place at around 1000 掳C per minute, even when using cryoprotectants.
If cooling takes place more slowly, the water in the cell freezes first and the consequent rise in concentration of dissolved substances within the cell kills it, with no hope of later revival. Only thin sheets of human tissue, and single cells, can be cooled fast enough.
Furthermore, optimum rates of fast cooling, and re-warming, vary widely between different tissue types.
In practice, cryopreservation is therefore successful only for sperm, blood, embryos, dermis, corneal tissue and the like. Even for small 3D organs such as the kidney, successful cryopreservation for transplant surgery has proved to be impracticable. Cooling to 4 掳C without freezing preserves the kidney for perhaps 48 hours, but that is all. Cryopreservation of larger organs, or the entire human body, is therefore most unlikely in the near future.
Green own goal?
Despite the evident promise of technologies to store carbon dioxide in the deep ocean with minimal threat to the environment (21 September, p 18), in July and August pressure from environmental interest groups stopped researchers in Hawaii and Norway from conducting experiments to study the long-term deep-ocean sequestration of CO2.
This confirms what many have long suspected: environmental interest groups are more interested in directing people’s lifestyles by limiting their energy use than they are in solving the problem of rising levels of CO2 in the atmosphere.
Letter
The reference to “underwater” storage of CO2 could be misleading. It is true that the Sleipner and Utsira formations underlie the North Sea, but similar techniques can be (and are) applied successfully to reinject CO2 into aquifers or oil reservoirs beneath dry land. It is important not to confuse this technique with releasing CO2 into deep ocean waters, an idea that certainly has its supporters but also raises a number of environmental questions.
However, if storage underground is to make a significant impact on our greenhouse gas emissions, there are also questions to be answered, such as: how will CO2 behave underground? And what are the risks of it returning to the surface?
Seeded by cosmic dust
Geologist Lars Franz茅n from the University of Gothenburg has found out that cold periods in our planet’s history tend to coincide with larger amounts of cosmic dust being deposited in peat bogs (14 September, p 24). Franz茅n suggests that dense clouds of cosmic dust cool the Earth by shielding the planet from sunlight.
Franz茅n’s findings are extremely interesting and may have real importance, but the mechanisms through which cosmic dust might alter the Earth’s temperatures are likely to be a bit more complex. You would need very high densities of space dust to create the kind of direct shielding Franz茅n proposes. The variations he found in the amount of cosmic dust deposited in Europe’s peat bogs are not large enough to support this hypothesis.
However, the dust particles falling on Earth could act as nuclei for cloud condensation. Even more importantly, cosmic dust contains a lot of iron, which can “fertilise” the oceans. Iron is one of the biggest factors in the growth of plankton: adding a kilogram of iron can increase the amount of plankton by several tonnes. And as a by-product of their metabolism, planktonic algae produce many kinds of aerosols, including DMS (dimethyl sulphide), that can act as nuclei for cloud condensation. Cosmic dust might thus cool the climate primarily by catalysing cloud formation over the oceans.