Breaking a butterfly
Once again I have to read nonsense about the “butterfly effect,” this time in your article on chance (14 March, p 30). A small event may indeed have large consequences if all the effects and effects of effects are linked in a very direct and linear way.
Hurricanes or tornadoes, however, are massive events composed of an effectively infinite series of small events or causes such that you could remove thousands, or tens of thousands, of events the magnitude of a butterfly flapping its wings without affecting the major event in any way.
The butterfly’s flapping is swamped and cancelled out by the other events. And of course, the system is completely non-linear.
Dorrigo, New South Wales, Australia
For the record
鈥� We said that the largest value that can be represented by a 32-bit integer is 2,147,483,647 (13 December 2014, p 21). Our programs would run safely if we got our data types right: we meant that a signed 32-bit integer can store values from 鈥�2,147,483,648 to 2,147,483,647.
The coolest shades
David Hambling describes a weapon that disturbs vision by heating the eyeball with infrared radiation (7 March, p 44). This will, fortunately, be cheap and easy to nullify. I foresee that infrared blocking sunglasses will become the “cool” eyewear for the military and anyone planning to riot.
Sawbridgeworth, Hertfordshire, UK
Little England
Your article on the genetic legacy of the UK states “there are inexplicably stark differences between inhabitants in the north and south of the Welsh county of Pembrokeshire” (21 March, p 54). This can be explained by south Pembrokeshire being a stronghold of the Normans in Britain. As I recall local history, the Norman king brought in Flemish people to subdue the unruly local population and farm the land. Welsh is not spoken by people local to Southern Pembrokeshire and the area is often called “little England beyond Wales”.
Cardiff, UK
Domestic dinosaurs
Thank you for “A world without chickens” (21 March, p 42). We now know that birds are dinosaurs.
The 22 billion domestic chickens alive must surely make them the most successful dinosaur species ever. But not even chicken dinosaurs are immune from extinction.
Barham, Kent, UK
Sellotape sunstone
I found Philip Ball’s account of the search for Viking “sunstones” (21 March, p 40) fascinating. You can easily try out something similar yourself. First find some polarised glasses, such as those 3D specs from the cinema. Now make yourself a small square with one to six layers of Sellotape randomly stuck together.
If you look through the glasses at the square, backlit by a computer screen set to display a uniform light blue or white, you will be surprised to find that the square looks like a prettily coloured Mondrian painting, with different colours depending upon the number of overlapping layers. Now go outside and look at the square against different parts of a cloudy sky. You will find that the Mondrian is lifeless near the sun or opposite, but springs into nice colours at right angles.
The effect works nearly as well with a piece of calcite. Maybe Viking sailors made their own Mondrians out of thin stuff like sheep gut or mica?
Basingstoke, Hampshire, UK
Ungodly aspirations
Chris Ford says that agnosticism is a more scientific position than atheism or theism (28 February, p 54). However, if someone told me there were fairies at the bottom of their garden, I wouldn’t say that I was agnostic about it, simply that I didn’t believe it.
Since I think the chances of there being any kind of god are about the same as fairies existing, I am quite happy to call myself an atheist.
Howick, Quebec, Canada
Ungodly aspirations
Steven Miles says “True scientists would not accept such a major axiom [as the existence of god] without proof” (21 February,p 54). True scientists would also not accept the axiom that there is no god without proof.
True scientists might decide that “the weight of evidence suggests” a particular conclusion, but seldom does science state a certainty. True scientists are good at saying: “I don’t know.”
Miles says that agnosticism is untenable, and just shows that one is afraid of the word “atheist”. This is nonsense. Being an atheist is just as irrational as being a theist. When Miles can prove god does not exist, I’ll be an atheist. Until then, I’m with E. O. Wilson.
Boulder, Colorado, US
Ungodly aspirations
Comments from E. O. Wilson (24 January, p 28) and subsequent letters on atheism, agnosticism and god all assume these terms have a well-defined meaning agreed by all. But they do not.
To me agnosticism is the insistence that it’s wrong to pretend to know what you don’t know, but to Chris Ford it’s “the assertion that the existence of god is unprovable” (28 February, p 54). If we can’t even know whether god exists, we certainly can’t know what she may want of us, so our lives, beliefs and ethics must remain godless. Thus agnosticism necessarily implies godlessness 鈥� also known as atheism.
London, UK
A ration of health
Your special report on the future of healthcare raises some good points, but it doesn’t address the fundamental problem of the UK’s National Health Service (21 March, p 22). Nye Bevan introduced the NHS in 1948 for everything “from the cradle to the grave”, free of charge at the point of need. It was excellent by the standards of the day, but in the day “everything” was not very much.
There was midwifery, some neonatal care, general practice, plenty of lung cancer (always fatal), and so on. Life expectancy was 65 years. There was a culture of self-reliance, and little appetite for prolonging life for the sake of it. So the costs of the early NHS were easily met by a tax increase.
More diagnostic tests and expensive scans are now used and more treatments are possible, some of them absurdly expensive. There is an obesity epidemic, diabetes incidence has more than trebled, and a rising incidence of mental health problems is poorly addressed. Above all, a huge increase in life expectancy and consequent morbidity has exploded the demographic time bomb that we health workers discussed in the 1960s.
“Everything from the cradle to the grave” must be replaced by defining what the NHS will and will not do. The required alteration in public expectations will be as radical as the introduction of the NHS itself was in its time. But there are no votes in that.
Sidmouth, Devon, UK
Alien odds
I was disappointed that Bob Holmes failed to mention Ernst Mayr in his otherwise excellent article on how evolution might replay (14 March, p 32). Mayr is the undoubted pioneer in this area, and in his essay “The probability of extraterrestrial intelligent life” (in Extraterrestrials: science and alien intelligence), he identified a series of eight or 10 ridiculously unlikely stages which life has passed through en route to evolving intelligence. Some of these we have greater insight into today, but most are as far-fetched as ever.
This side of the debate is visited infrequently these days: we seem to prefer the more sensational claims of SETI physicists.
Cygnet, Tasmania, Australia
Red Lady deodorant
I was intrigued by the Red Lady of El Mir贸n (21 March, p 8), and I would venture to explain why there is so much pollen in the cave where she was buried.
We can be sure that, as the article stated, this woman was highly venerated, and also that the people who buried her would not have been able to halt decomposition. This points to a problem that they were clearly respectful enough to put up with.
The pollen may, then, indicate the use of copious flowers to cover up the smell. These would also decay and so be constantly replaced, leaving large amounts of pollen.
Barnsley, South Yorkshire, UK
Machines who think
I was shocked that the creators of iCub appear not to understand the implications of their effort to build a robot with a self (21 March, p 36). They are striving to create “consciousness”.
Researcher Tony Prescott writes: “Sometimes it even leaves me with the surprising feeling that ‘someone is home’.” I can well accept, as can he, that being sentient is the accumulation of processing power and decision-making abilities. His effort to create a sentient being should therefore be governed by the same regulations as primate experimentation.
Aylsham, Norfolk, UK
Migraine et al.
鈥� Once again, we advise readers to discuss any migraine treatments with their registered physician.
Migraine et al.
As a “migraineur” I appreciated your recent update on migraines. A report in 快猫短视频 led me to search for a vagal nerve stimulation device (17 August 2013, p 12). It has profoundly helped my condition.
However, reading and concentrating on articles with such busy graphics is hard on the migraine brain.
Cobble Hill, British Columbia, Canada
Migraine et al.
I was very interested to read your recent article on migraine, and especially about the many different categories that exist (7 March, p 38). I was treated unsuccessfully for migraine for 14 years, before finally being diagnosed instead with the lesser-known condition called cyclical vomiting syndrome.
Like migraine, CVS is episodic. It is characterised by severe nausea, retching and vomiting, which occurs five or six times per hour at the peak of an attack.
CVS seems to be associated with migraine, although no one yet understands the relationship between the two, or why CVS occurs. There is more about the condition at .
Windermere, Cumbria, UK
Gateway doubt
Your interview with Denise Kandel gave the impression that mouse experiments show there is such a thing as a “gateway effect”, in which nicotine use leads to the use of other drugs (7 March, p 28). But we have solid and clear human data.
Over the past 60 years, the prevalence of smoking among young men in the UK has from 80 per cent to under 20 per cent. If use of nicotine increased use of other drugs, this steep reduction in smoking would have resulted in a drop in the use of other drugs as well. There is no sign of this. The gateway effect is an attractive hypothesis but it does not exist.
London, UK
Fuelling cyclones
In ripping through Vanuatu, Tuvalu and the Solomon Islands (21 March, p 6), cyclone Pam has become the benchmark for massive weather events that occur far away from the energy consumption responsible for our warming weather patterns.
These Pacific islands are the victims of the industrial world’s energy excesses. How much will it cost to help these island nations rebuild, and more importantly, how much will the industrial world contribute 鈥� or for how much longer will it keep making band-aid repairs?
The easiest path to take really is to discontinue fossil fuel consumption and become a renewable world. Otherwise, the Pacific nations will be battered out of existence.
Gold Coast, Queensland, Australia