Draining both ways
I was disappointed that your article on the brain drain was just as one-eyed as such discussions usually are (26 April, p 56). How about opening the other eye to the inward drain?
For example, Britain has many scientists from New Zealand, such as myself. Some key issues arise. Are incoming researchers welcome in the present climate of immigrant-phobia, or merely tolerated after worming their way in? And if they are welcome, why doesn’t Britain encourage more people from other countries to come here, particularly to study for their PhD?
There are many students on the Continent and in the Commonwealth who would like to do their PhD in Britain rather than the US if the financial path were smoother. I don’t believe the argument that this will deprive other countries of the people they need.
So stop whingeing and take some simple steps to attract more good-quality PhD students from overseas. This would also make a positive contribution to the world.
Dissimilar twins
Your editorial reports that cloning animals does not ensure the production of identical individuals (26 April, p 5). You also say that we should not be too surprised, since identical twins have their distinct personalities. It is sometimes forgotten that they can differ also in less subtle characteristics.
Unlike cloned cats and pigs, identical twins originate from a fertilised egg that has split into two. That is why such twins are properly referred to as monozygotic, since they are derived from a single zygote. It has been known for many years that despite starting off with identical genes, the two members of such a twin pair frequently differ with respect to diseases like cancer or congenital malformations like cleft lip, where only one twin is affected. This is in contrast to genetically determined characteristics like the ABO blood groups, which are the same in both twins.
It follows that we must distinguish between two types of genes. Those that give rise to blood groups are always associated with a particular character that is transmitted according to strict Mendelian rules. On the other hand, conditions like cancer and congenital malformation are critically dependent on rates of cell proliferation, and these are also affected by environmental factors such as nutrition. So while the genes are involved in these processes can affect the probability of an outcome, they cannot finally determine it.
Failure to distinguish between genes that consistently give rise to easily recognisable characters and others for which there is no such clear-cut relationship causes much confusion.
Trusting strangers
In your article about trust, the authors describe how in an experiment half the players were willing to hand money over to an unknown stranger in the hope that it would later be returned, and that three-quarters of those strangers did indeed return the cash (10 May, p 32).
Perhaps because they were looking for something else, the authors miss the obvious conclusion that is good news in a world where we are deluged with bad news every time we turn on the TV or read a newspaper. People are more trustworthy than they are trusting. That is, we underestimate how good other people are.
Surplus plasmons
Concerning your article about plasmonics, you might be interested to know that many of the effects described as novel and appearing to require plasmons have been well known in microwave engineering for a long time (26 April, p 30).
For example, large periodic arrays of slots in a perfect conductor can transmit an electromagnetic wave without hindrance at certain microwave frequencies. A characteristic of such slotted structures is that the electric field can be very intense over the slots and becomes larger the narrower the slots. It is therefore not necessary to employ surface plasmons to compress electromagnetic energy.
An apparent difference is that such slotted structures usually have dimensions comparable to half a wavelength in their long dimension, certainly much larger than those described in the article. However, this turns out not to be essential.
Although I am no expert in plasmons, it seems to me that the applications are important principally because they allow a coupling mechanism in metals at optical frequencies that was not previously apparent. In essence, the metals are not behaving as perfect classical conductors. However, many of the effects described do not generally require plasmons and can be achieved using other coupling mechanisms, as can be demonstrated at microwave frequencies.
Endless argument
In support of Stephen Hawking and Michael Brooks, Crispin Rope quotes Karl Popper’s remark that G枚del’s incompleteness theorem applies to all theories of physics (26 April, p 28). This seems dubious.
G枚del’s theorem only applies to sufficiently rich formal systems, such as number theory. In particular, it can only apply to systems that attempt to deal with infinities. Although the mathematical methods by which we obtain equations of physics may involve working with infinities and infinitesimals (for example, calculus), the real world probably has neither. If the equations are nonetheless correct then it should mean that the use of such methods is merely a convenience. That is, it should be possible to obtain them without recourse to the infinite.
Autistic humour
I write in reference to your article about the possibility of Einstein and/or Newton having had Asperger syndrome (3 May, p 10).
My 15-year-old son has been classed by his consultant as having severe Asperger syndrome yet he has an extremely well-developed sense of humour, which the psychiatrist you quote, Glen Elliott, would see immediately from our video collection: Monty Python, Fawlty Towers, Mr Bean, The Simpsons, Red Dwarf, Austin Powers, The Italian Job, Ocean’s Eleven and so on. He loves comedians such as Harry Enfield and Lenny Henry. A straw poll amongst my friends with autistic children and adults with Asperger syndrome indicates that a sense of humour is in fact common.
When psychiatrists and psychologists like Elliott make blanket statements about the abilities and characteristics of those with Asperger syndrome, it can have very detrimental effects: it could, for instance, mean that children like my son might remain undiagnosed, and fail to receive the help they need.
A tip from Buck
Reading Duncan Graham-Rowe’s piece about Taser landmines (26 April, p 12) brought to mind an episode from that 1980s science fiction classic Buck Rogers in the 25th Century. In one episode some rogue “bad guy” was terrorising the inhabitants of a planet by shooting electricity from his fingertips.
This being the 25th century, everybody but Buck had forgotten what electricity was, but using his 20th-century know-how and bits from the local museum Buck managed to build a device that absorbed the shock and then sent it back to the bad guy. Planet saved. (For non fans: Buck was from the 20th century and had been frozen in his shuttle then revived in the future.)
If Buck can do it why not us? What about wearing an insulating layer near the skin over which you wear a second layer made of a metallic foil or maybe a garment laced with small copper wires every few centimetres. These could be connected by an insulated wire that runs down the leg to a metal probe in the shoe that disperses the charge to the ground.
A more radical idea might be to stick insulated conductors to the skin directly, insulation underneath, surface exposed. Again these will be spaced all over the body, and again the charge is dispersed down the leg.
Or we could take a tip from Buck and store the charge directed at us from the “good guy” in a capacitor and zap him back.
For the record
鈥� In the letter from Clive Semmens (10 May, p 26) an editing error led to the decay product of thorium-234 (Th-234) being give as palladium (Pd). It is in fact protactinium-234m (Pa-234m).
Squishy rocks
Reading the article on deflecting asteroids (19 April, p 36) caused me to go back and read the article on the formation of Earth-like planets (29 March, p 24).
In the latter, Thomas Clarke stated that his models of Solar System formation required an additional energy source, such as from the decay of aluminium-26 from a nearby exploding star, to allow rocky planets to form. Without this additional energy to cause a partial melting of the rocky material of the asteroid belt to form squishy rocks, impacts would result in the rocks rebounding like snooker balls and not combining to create planets.
The article on deflecting asteroids has caused me to doubt this theory. This article states most asteroids are porous piles of rubble floating in space, held together presumably by gravitational effects, and as such are capable of absorbing a great deal of energy as they crush like polystyrene packing material.
This would imply that impacts between such agglomerations of rock would not result in rebounds but in larger piles of rock, as the impact energy would be absorbed in much the same way as in the squishy rock theory.
Perhaps this mechanism alone could lead to the formation of rocky planets in the Solar System. Small balls of dust and rock from the asteroid belt could have impacted and combined to form successively larger asteroids until planet size was reached.
If this is the case then perhaps Earth-like planets are not as rare as Clarke estimates.
It's still life
Sylvia Pag谩n Westphal writes that parthenogenetically cloned human embryos “die after a few days” and therefore “could never become human beings. So destroying these embryos to obtain stem cells would avoid the ethical concerns that have led to restrictions or bans on embryonic stem cell research in many countries” (26 April, p 17).
I for one am unable to distinguish any ethical difference between the destruction of a human life capable of adulthood and one with an accidental or intentional limitation to its lifespan. As for religious or moral opposition to embryonic research, I am sure that the sanctity of human life does not depend on such limitations in potential lifespan.
Memory therapy
The model of memory recall in which a consolidated memory becomes labile when recalled and may then be reconsolidated in an altered form helps explain the success that hypnotherapy and neurolinguistic programming achieve in removing entrenched phobias, often in single sessions (3 May, p 26).
The therapist guides the patient in a relaxed state to recall the circumstances linked to fear, in a way that avoids the fear reaction 鈥� for example, by visualising the situation as a distant picture, or a film that can be run backwards and forwards, chopped up and destroyed. The memory may be altered by adding someone the patient trusts, or by associating it with funny music.
An imaginative therapist conjures up many ways of removing the fear. My wife is a hypnotherapist and I have been surprised by the wide variety of phobias removed by these seemingly simple techniques: fear of flying, motorways or meeting people seem more common than the traditional spider phobia, but all are removed by reconsolidation of the memory.
In the experiments, the rats lost their fear of the box, but was this because they had lost all memory of the box or, as in the case of my wife’s patients, they had lost the link with fear? Including in the box a reward obtained through a pre-learned maze could test this.