Seaside what?
A sentence in your story about the miniature endoscope is perhaps one of the most confusing I have ever encountered (24 January, p 21). Perhaps you can explain it to me, as I have also confounded several co-workers by having them read it.
The sentence reads: “These are single fibres with microscopic holes running right through them, like the lettering in a stick of seaside rock.”
The phrase “like the lettering in a stick of seaside rock” is used so easily, as if everyone were familiar with it. I find this incredible. What exactly is a stick of seaside rock, and why does it have lettering running through it? Is this a common feature of English seasides? I find the whole topic intriguing.
The editor writes:
鈥� Apologies to readers who are not acquainted with the joys of a British seaside holiday. The rock we referred to is a long stick of hard candy with lettering running through it, usually spelling the name of the resort where it is sold. It is immortalised in Graham Greene’s novel Brighton Rock. An explanation of how it is made, and how the lettering is inserted, can be found at .
Back to the dark age
In his letter, Peter Inkpen proposes storing our knowledge for future generations, in case our civilisation destroys itself. He also notes that we have thoroughly plundered our natural resources (20 December 2003, p 34), something which in fact is likely to be a far more serious problem.
If we have consumed all the easily available sources of ores, coal, oil and other essentials for industrialisation, how will people of the future reindustrialise? Will they skip to the post-industrial information age? I think not. How will dark-age humans be able to go mining under the sea for coal, or seek out oil offshore or in the Russian tundra?
The industrial revolution started in parts of England where there was available labour and easily winnable coal, iron ore and limestone to make iron and steel. This made it possible to make power systems and machinery. Classical literature describes steam turbines, for example, that could not be developed then.
How would our dark-age successors find the resources to take advantage of today’s knowledge, even if it were available to them? Perhaps industrial civilisation is a fragile thing that once broken cannot be mended, and this is why we cannot find any sign of the thousands of intelligent life forms that are supposed to be out there on other Earth-like planets. They have been through their industrial age and lacked the resources to rebuild it when it failed.
Tear gas at 30,000 feet
Rather than use tasers to incapacitate terrorists on aircraft (17 January, p 19), I suggest a simple, well-proven and relatively low-tech solution. In the confined space of an aircraft, tear gas would be brilliantly effective in incapacitating all passengers until the plane is able to land safely.
I can testify from personal experience that tear gas disables fit, healthy adults in a very short time. People become nearly blind, salivate uncontrollably and feel as if they are dying. Recovery is total and rapid in fresh air.
The ventilation system of an aircraft could quickly distribute tear gas through the passenger cabin once activated by the pilots or cabin crew. The pilot could, if necessary, also trigger the release of oxygen masks to provide some relief for passengers in their seats.
Releasing tear gas into the cabin would give all the passengers a truly miserable flight experience, and put those with respiratory or cardiac illness at significant risk. But it would likely be preferable to an on-board shoot-out between terrorists and sky marshals.
Sex, drugs and Darwin
Calling Darwin’s theory of sexual selection “false and unfixable”, as Roughgarden does, makes for good Darwin-bashing. But the charge doesn’t stand up. It is like saying that because many organisms use food for purposes other than nourishment (giving an apple to your teacher, for instance), the “theory” of the struggle to obtain nourishment is “false and unfixable”. “Power to control access to reproductive opportunities” sounds important, but no matter what other uses sex is put to, which genes are passed on depends on whose gametes meet.
Roughgarden cites Bagemihl’s list of 300 species showing homosexual behaviour. That amounts to fewer than 1 per cent of all vertebrate species, which still sounds exceptional, rather than pervasive.
Letter
Roughgarden argues that homosexuality does not fit the criteria for a typical genetic disease. Could this perhaps tie in with research on oestrogen mimics in insecticides and many other common chemicals, which shows that these chemicals are washing into every ecosystem on Earth? There they influence the development of sexual organs, and stimulate hormonal changes.
These developments have been documented over the past decade and have coincided with observations of never-before-seen homosexuality, hermaphroditism and deformed gonads in organisms ranging from fish to polar bears. I would suggest that the book cited in this article, Biological Exuberance: Animal homosexuality and natural diversity, is not a catalogue of naturally occurring homosexual incidences but an alarming update of the ever-increasing number of species being affected by an overwhelming tide of oestrogen mimics. Why should we humans think we are immune to such effects?
Dope and low fertility
Your story about the rapidly declining sperm count of British men says that researchers at the University of Aberdeen could find no specific cause for this phenomenon (10 January, p 6). Apparently the researchers suggested that water-borne pollutants, tight underpants or working in a warm environment might be to blame.
Based on other more recent studies, we suspect that the real culprit is far more likely to be increased use of cannabis. As the UK has removed more and more restrictions on marijuana use, its popularity has escalated and users abound. The impact of cannabis on sperm and egg cells has been known for 20 years, and more recent studies show that cannabis use contributes to premature death of these reproductive cells.
The marijuana connection seems far more likely than tight underpants. It might be a good idea to go back to the database and find out which men were using cannabis during the period covered by the study.
Male-female split
I am puzzled as to why Guy Cox finds it puzzling that we are not hermaphroditic (10 January, p 30). There are good reasons for the evolution of dimorphism in gametes, resulting in big, less mobile ones and small, mobile ones. When that happened, selection for different behaviour on the part of the “females” that produce the big gametes and the “males” that produce the small ones began to operate.
Co-occurrence of the two kinds of gamete production within one body precludes the development of such differences. No wonder simultaneous hermaphroditism is the rare exception rather than the rule among vertebrates.
Millipede taste test
In her story about intoxicated animals, Hazel Muir wrote: “Black lemurs in Madagascar get their kicks from the toxic chemicals exuded by millipedes to defend themselves from insect attack.” She then asked how someone biting a millipede would be affected, and concluded: “We don’t know 鈥� we like to think no one has tried it” (20 December 2003, p 56).
I can confirm that I have, in fact, tried biting a millipede, though I am unfortunately not able remember many details since at time of biting I was under the age of 2. My mother has stated that my response was not indicative of wild ecstasy but, as with the lemur, frothing at the mouth and grimacing were seen. No long-term side effects have been noted thus far, although my colleagues at work may disagree.
The millipede in question was a native of Zimbabwe, where it is known as a songololo. Whether it differs in flavour from millipedes found in Madagascar is not a question I am keen to investigate personally.
Bitter-sweet
Now that Beverly Tepper has made a “bitter blocker” (10 January, p 36), please could she develop a sweetness blocker for when my Dad puts sugar in Mum’s tea, and a salt blocker for when Mum salts the potatoes twice?
Crash in any language
I was interested to read about the proposal to put automatic transmission of crash information into cars (17 January, p 22). But rather than requiring the E-merge software on board the car to issue its message in several local languages, it would surely be much simpler and more robust to define a set of numerical codes. These could be translated at the point of arrival, which already knows what language it needs. Then the only country-dependent information within the car would be the list of phone numbers to call. These numbers are already being standardised, and the numeric service could easily be extended to new language areas.
An automated “handshake” could also be added in order to guard against malicious false alarms, for example by having the emergency service system call the car back for confirmation.
The harder they come
I enjoyed your cover story about “quantum knots” and its enthusiastic engagement with an interesting and often difficult subject (24 January, p 30). It is a shame that some of the central facts were garbled.
Paul Parsons asserts that a quantum computer could be used to perform NP-hard computations quickly. That is wrong. The situation here is complicated by the fact that we don’t even know whether conventional computers can perform NP-hard computations quickly 鈥� this is the famous “P = NP” problem 鈥� but there is no good evidence that a quantum computer would fare any better than a classical one in this regard.
Parsons also seems to believe that finding the factors of large numbers is an NP-hard problem. That is not true either 鈥� or rather, it isn’t known to be true and is widely suspected not to be. The problem of calculating the Jones polynomial of a knot is NP-hard; in fact it is “#P-hard”, which is even worse 鈥� but even a topological quantum computer cannot calculate the exact value of the Jones polynomial, so it doesn’t follow that such a computer could solve NP-hard problems.
The human factor
Mark Buchanan makes some interesting points in the article “Know thy neighbour”, but the conclusions are somewhat simplistic with respect to computer networks, specifically the internet (17 January, p 32). The suggestion is that upgrading critical network links to higher speeds may boost the carrying capacity of the entire internet. But this would only affect traffic needing to traverse the particular geographic regions affected by the link. It would make no difference to the internet as a whole.
Raw bandwidth is relatively plentiful. Networks are already managed at a more sophisticated level. “Traffic engineering” provides specifically for services like video: network operators constantly monitor usage patterns and modify the way traffic uses the “pipes” to ensure bandwidth is available to applications that need it.
The real difficulties lie in getting network operators to agree to honour each other’s policies on, for example, the priority given to different packets of data; and the largely unpredictable nature of much end-user demand. These are social rather than technical factors that are hard to account for.