Choosing the child
It is true that one round of egg retrieval will give limited choice in the selection of embryos for implantation (24 July, p 3). It is also true that several rounds would give a great deal more choice, as will inevitable progress in IVF technology.
I am the father of nine children whom I love dearly. I cannot begin to calculate the time and money poured out over the past twenty years to give them the best possible environment. Imagine how much trouble I would take to give them the best possible heredity.
This is something that will become far more meaningful as we learn to predict not just trivial traits like eye colour, but also vital ones like intelligence and resistance to cancer.
We have banned human cloning and rightly so, because with current technology it harms the child. We don’t harm a child by ensuring that they have the mind to achieve what they want in life, and won’t die of a hideous illness in their fifties.
I’m sure the biological Luddites will continue to howl, but in the end, they will be defeated by the wishes of concerned, loving parents.
Tax on warming
Your report on encouraging the use of renewable energy sources states that the only way to make most of them attractive is through subsidies, since “there is no agreed way” of surcharging for the environmental costs of fossil fuels and nuclear energy (17 July, p 6).
Why the defeatism? A progressively rising carbon tax is the foremost mechanism cited in the Royal Society’s 2002 report on economic instruments to cut carbon dioxide. It is easy for industry to plan under, and in governments’ interest to enforce.
A carbon tax (or tradable permits) could underpin an effective global anti-warming initiative. For example, the European Union and concerned developing countries could form an economic zone progressively introducing a carbon tax, plus rising tariffs on the produce of other states who have not taken similar measures.
That could protect industries within the zone from cheaper imports, encourage outside states to join the mechanism, and lead to much coal use and deforestation becoming uneconomic. The revenues raised could be used to compensate coal industry stakeholders (and others).
This would mean abandoning the World Trade Organization, but it is now time for all concerned scientists to declare that abating warming is vitally more important than any existing free trade agreement or process.
Letter
It was disappointing to see once again multiple mentions of subsidies for renewable energy coupled with an implication, by silence, that fossil fuels are not subsidised.
In fact, numerous studies indicate that fossil fuel and nuclear energy subsidies are vastly higher than support for renewables. For example, in 1999 International Energy Agency countries gave $2.95 billion for nuclear research, excluding fusion, and $646 million for renewable energy. The European Union Sixth Framework Programme 2002-2006 for supporting research and development has earmarked 鈧�1.23 billion for nuclear energy and only 鈧�810 million for renewable energy.
One of the background papers for the recent Renewables 2004 conference in Germany, available online, summarises some of the published work on subsidies and tells us that, globally, annual fossil fuel subsidies between 1995 and 1998 were $151 billion compared with $9 billion for renewables and end-use measures. One estimate of the value of annual support for coal in Germany alone in 1998 was $5 billion.
Telltale prints
“Technology trends” mentions that a new cellphone incorporates a fingerprint reader as a safeguard against theft (24 July, p 26). Several laptop computers, the odd mouse, even some experimental smartcards now have this “security” feature. Yet it is a worrying gimmick, closely equivalent to writing the PIN on the back of your credit card.
A majority of commercial fingerprint detectors can be fooled by replica prints. In 2002, Japanese cryptographer Tsutomu Matsumoto devised the infamous “Gummi Bear Attack”, in which a gelatin candy moulded with latent fingerprints transferred from a drinking glass proved effective against 80 per cent of readers tested (see ).
So if you lose your fancy phone, a clever thief will find your biometric security information very conveniently left behind all over the keypad.
One wonders whether disposable latex gloves will become the next weapon in the war on identity theft?
Encrypted batteries
NEC Japan has developed a phone that will only work with the manufacturer’s own batteries (17 July, p 20). The purported reason for this is to protect cellphone owners from cheap, counterfeit batteries that have shorted out and exploded.
How many people do you know who have been injured by exploding batteries? Yet millions of us use alternative makes of batteries in much of our domestic equipment.
Could it be that the real reason is because companies such as NEC make huge profits out of accessories such as batteries and simply want to keep all this profit for themselves?
Contrary quantum
The results of Shahriar Afshar’s experiment are just what would be predicted from a conventional quantum-mechanical analysis of the experimental set-up (24 July, p 30). As all the leading interpretations of quantum physics (including those referred to in the article) are designed to predict the same experimental results as conventional quantum theory, none of them can be logically falsified by this experiment.
To imply that complementarity means that light must always be 100 per cent a wave or 100 per cent a particle is a gross oversimplification. More correctly, the state of a quantum system can often be represented as a combination or “superposition” of complementary descriptions, such as “wave” and “particle”. The closer it is to one of these the further it is from the other, but in general neither description is correct. Given this, we can see that Afshar’s experiment, rather than refuting complementarity, actually exemplifies it in a rather elegant way.
Also, whatever the weaknesses of Bohr’s approach to quantum physics, it is quite wrong to imply that he identified observation or measurement as a conscious human act, such as looking at oneself in a mirror. For Bohr, observation meant the recording of results by apparatus undergoing irreversible changes such as occurs when a counter clicks. The foundations of quantum physics are puzzling and controversial and really do not need further obfuscation.
For the record
鈥� Mary Done, who co-authored a report demonstrating that acupuncture prevents sickness after operations (31 July, p 15), is based in the School of Rural Health at the University of New South Wales in Albury, Australia, not at the New Children’s Hospital in Sydney as stated in the story.
鈥� In our story on rhinos (31 July, p 12) we misspelt the name of one of the researchers quoted. Ellen Dierenfield should have been Ellen Dierenfeld.
Wonder of white
I find it incredible that people just don’t like white roofs (19 June, p 22). White roofs have been a trademark of Bermuda architecture for over 400 years and today it is illegal to build a non-white roof.
Though I would like to think it has to do with the genius of our early settlers it probably has more to do with the early availability of materials in the form of Bermuda’s natural white limestone.
To convince the world of the beauty of a white roof, simply get them to come to Bermuda. Once the world has copied Bermuda’s cool white roofs perhaps it will also be converted to the knee-cooling effects of our business attire, Bermuda shorts and knee socks鈥r perhaps not.
Fox count
We have a Falklands fox (28 February, p 31)! This makes the world total four.
Heavy Higgs?
The article on the search for the Higgs particle contained much speculation about its mass (17 July, p 38). This raises the question: if the Higgs particle gives mass to other particles, what gives the Higgs its mass?
Letter
Dana MacKenzie suggests that the management of CERN, the European Centre for Particle Physics, made a grave error in its decision in 2002 to terminate the Large Electron Positron (LEP) accelerator programme when just one of four experiments had reported borderline evidence for the Higgs particle. But later analysis showed that they actually made the correct decision.
Three years later, all four experimental teams published a paper in Physics Letters B (vol 565, p 61). This was the culmination of a very careful examination of all the data. They concluded that the statistical significance of the purported Higgs signal had dropped and was equivalent to a standard deviation of 1.7 鈥� hardly compelling, even for the medical and social sciences.
Letter
I have to take issue with the statement that “this experiment is seeing evidence of light behaving as a wave and a particle at the same time”. This is simply not true. Given the physical layout of the experiment, the diffraction measurement is clearly performed some finite time before the particle measurement. They are not simultaneous.
Letter
Afshar claims that his experiment violates Bohr’s principle of complementarity. Quantum mechanics describes the experiment through a wave function that gives the probability of detecting a photon at any point.
Afshar places wires at points where the wave function vanishes. Unsurprisingly, as there’s nothing for them to interact with, the wires have no effect. But all this shows is that there are points where the wave function vanishes, just as a conventional interference experiment has dark lines on the screen where the wave function vanishes.
In both cases the wave function determines that there is no light at certain points or, to put it another way, no photons will be detected at these points. In neither case does interaction with the wave function take place 鈥� how could it, when there is no wave function with which to interact?
Bohr’s point about complementarity was that a quantum system can’t simultaneously interact as both a particle and a wave. In both Afshar’s and the conventional interference experiments, no interaction at all takes place at the null points. In the absence of interactions, complementarity is silent and, conversely, nothing can be said about complementarity.