We hate lift-off
You report that the US Congress has passed a bill encouraging space tourism (18 December 2004, p 4). God, that’s depressing. In a world slowly waking up to the reality of climate change, people with more money than social conscience are being encouraged to chuck thousands of tonnes of CO2 at the rest of us. Where then is the incentive for me to use energy-saving bulbs and turn my central heating down?
What about the scientists that are doing this? Do they have no conscience about the planet? How do they justify it to themselves?
Gather no moss
From Peter Abrahams
A chance juxtaposition of articles in your magazine may solve two problems in one go. If all the excess feathers mentioned in “Down, but not out” (25 December 2004, p 40) could be turned into a dried moss substitute, this could realise dreams of a green Christmas (p 59).
Chop the feathers up small and mix with a little natural green colouring, some glue made from the quills and a bit of ingenuity, and I am sure we could produce a soft, natural product that resembles dry moss. Thus the environment could be saved twice: once from drowning in feathers and once from losing all its natural moss.
London, UK
From Nicholas Dore
Your article reminded me of the use of moss in the 19th century in the creation of special effects in the theatre. In Theatre Lighting in the Age of Gas (Society for Theatre Research, 1978) Terence Rees mentions the spores of the clubmoss Lycopodium clavatum blown across a flame to produce a bright flash of light.
Since reading that account I have wondered just how the moss was harvested. Was it cultivated, or was the countryside denuded of the stuff for use by apothecaries and theatres? If it was indeed cultivated, perhaps we could learn from this and produce renewable moss “farms”.
Magnesium powder later replaced the moss spores, and was used until fire regulations put a stop to fireworks in theatres. Even so, it appears that the use of the moss spores for stage effects may have lasted into the 20th century.
Lincoln, UK
Cosmic correction
Your article “Universe map runs into local difficulty” did a good job communicating the nature of our analysis of the “oldest light in the universe”, measured using WMAP, the Wilkinson Microwave Anisotropy Probe (11 December 2004, p 10). We would, however, like to offer an important clarification: we do not believe that our results “throw into question the data’s relevance and accuracy”. We take WMAP’s data seriously, and question neither its accuracy nor its relevance. Many results derived from the data appear to us to be very robust.
The article goes on to say that we are “casting doubt on the interpretation of the data and, in turn, on some of the models that spring from it”. We do believe our work and that of others casts doubt on cosmological events as the cause of the largest-scale fluctuations in the WMAP data. We also think it suggests that either some subtle contamination has crept into the data or the WMAP analysis or, more likely, that the largest-scale fluctuations are caused by some physical effect associated with the solar system or its immediate neighbourhood. However, we agree with the common interpretation of the WMAP data at smaller scales.
Global expansion
We wonder whether the thermal expansion of the Earth’s crust has been overlooked when considering the effects of global warming. We think that there is at least a possibility that it could affect seismic activity around the world.
Three years ago we discussed this with a senior member of the planetary sciences team at NASA, who suggested that the effect, though real, would be too small to be significant or measurable. But a nagging doubt remains. Consider the Earth and its atmosphere as a thermal layer cake, in equilibrium when averaged over, say, a year or a decade. If we disturb that equilibrium by raising the temperature of the cool side, through global warming at the surface, this will raise the temperatures of the intervening layers. The crust will then attempt to expand laterally.
The coefficient of thermal expansion of granite is 0.0000085 kelvin-1, while that of sandstone is 0.0000125 kelvin-1. A typical tectonic plate is over 2000 kilometres across, so for a mean change in crustal temperature of 1 kelvin over some period of time (perhaps 10 or 100 years) it should expand by some 20 metres, either divided between the edges or, if one edge is effectively pinned, at one edge only. It does not seem likely that this effect would by itself cause seismic activity. But could it trigger an increase in the frequency and/or the severity of naturally occurring seismic events?
We appreciate that the plates are not homogeneous and that the geological record shows no evidence for our theory, such as a reduction in seismic activity during the ice ages. Also, we have not taken into account such factors as the thermal inertia of the oceans and crust, which will limit the rate of temperature change. We do feel, however, that this merits further thought.
Rudder lowdown
Paul Summers reports correctly that aircraft do not use their rudders to steer while taxiing, but the editor is also correct in saying that pilots use the rudder pedals when on the ground (18 December 2004, p 28). Many planes are steered on the ground by the use of their rudder pedals: the pedals operate the nose wheel which can be turned as required, while the rudder, which would have no effect at taxiing speeds, is locked.
During the take-off run, steering is initially done by the nose wheel, but with increasing speed and the gradual release of the load on the nose wheel the rudder is unlocked and takes over directional, or yaw, control. After the plane leaves the ground the nose wheel automatically locks in mid-line 鈥� the required position for landing.
Law of laws
From Steve Sheen
Good heavens! Has so much time gone by since Harold Faber published The Book of Laws that we now need an update to cover the observations of a new generation, such as (to paraphrase): the faults in any given artefact of technology are observable only by those unqualified in their diagnosis (Feedback, 11 December 2004)? This resonates somewhat with Douglas Adams’s concept of the recipriversexclusion, which might be phrased as “the correct solution is excluded in all proposed solutions” and which may hint at a deeper and fundamental perversity of natural and social phenomena.
It is true that The Book of Laws contains no exact equivalent of Feedback’s proposition. In fact the observation might be contrary to Watson’s law which states: the reliability of machinery is inversely proportional to the number and significance of any persons watching it. For a generalised demonstration of the effect, think of the celebrated attempt by Bill Gates to launch Windows XP. Yet the universe is surely contrary enough for both to be true. So, good luck Feedback in your launch of a new law. I have no idea what you might call it but, as Faber’s law reminds us, “If there isn’t a law, there will be.”
Gooseberry Hill, Western Australia
From Lance Stewart
Feedback asked readers for the name of the law that covers appliances that mysteriously start to work again in the presence of a repairer. This is covered by Stewart’s first law: ailments and their symptoms will diminish in direct proportion with their proximity to the treating doctor, usually leaving the patient mumbling something vague about having felt pain somewhere.
However, Stewart’s second law is even more apposite: entropy will mimic order whenever threatened with repair. And yes, there is a third law that states: faults that are intermittent are the environmental manifestations of nature blowing raspberries. Stewart’s laws are based on first-hand experience. Unfortunately.
Ipswich, Queensland, Australia
Rules of attraction
I read your article on rules of attraction with some interest, but I feel the whole story has not been told (18 December 2004, p 34). Having becoming a widower a couple of years back at the age of 60-plus, I recently felt myself ready to enjoy female company again. Through a dating agency I met a single woman of my own age and with compatible interests, and it became clear to both of us within a couple of minutes of our first meeting that we found each other attractive. We are both pleased that romance has once again begun to blossom in our lives.
Your article doesn’t account for what is happening. Obviously her fertility is not an issue for me, nor is my material wealth a matter for her, as we both know she is quite a bit richer than I am. So what exactly is going on, from an evolutionary biological point of view?
spit hcraeS
There are further genuine uses for backwards Google searches (Feedback, 18 December 2004). HTML in Hebrew is not for the faint of heart. For one thing, HTML by default goes left to right, while the Hebrew text goes right to left. There are computing standards for text direction, but they are not universally observed. Search engines like Google often index badly made pages backwards. Sometimes the text displays backwards as well, and one gets used to reading Hebrew backwards.
Though will search, for example, for my name spelled both ways, readers may still find elgooG useful. The search page at does the same for Arabic.
Glacier blankets
At the top of Mount St Helens there is a new glacier. Its rapid growth is due in part to the insulating layer of rock debris on the surface of the ice (27 November 2004, p 32). Can we use this effect to stop the global melt? If we covered a glacier or ice sheet with a thin layer of powdered rock, would we preserve the ice?
Lousy longevity
I noted with interest that Stephen Barker has trouble keeping his experimental lice alive (25 December 2004, p 65). He doesn’t state the amount of time he needs, but my daughter has kept a number of lice (removed from her children’s hair) alive in a jar for three days. They had air but were not fed. By the third day, when she terminated the experiment, they were still moving though a little sluggish.
Are British head lice more robust than Australian ones? Would Barker like breeding stock? We appear to have an inexhaustible supply here.
Late developer
I read with great interest your report on the two young scientists, Antoine and Louis Cyr, who have diagnosed pituitary damage in the cartoon character Tintin (18 December 2004, p 18). They are, however, using incomplete data when they report that Tintin’s symptoms include an absence of libido.
The researchers may not have read Tintin’s last adventure, Tintin and Alph-Art, which was left unfinished at the time of creator Georges R茅mi’s death in 1983. In this story, Tintin shows a strong reaction to an attractive young woman in a skimpy skirt. Tintin’s libido may have taken 60 years to develop, but it arrived eventually.
Also, I have never understood why Tintin is so often described as a reporter. Several of his adventures end with Tintin’s latest triumph being widely publicised in news stories written by other journalists, but if Tintin himself ever filed a news dispatch in his many years of adventures, I must have missed it.
For the record
鈥� The Cassini probe passed through Saturn’s rings on 1 July 2004, not 1 June as we said on 25 December 2004, p 16.