How do bicycles stay upright?
Without riders, bicycles fall over, so it’s no surprise physicists still can’t explain why they stay upright (5 September, p 30).
Handlebars control the course of the contact between wheels and road, but give no direct control over the path of the rider above. They are used to maintain an unstable “upright” equilibrium 鈥� except uprightness is only for going in straight lines. Bends require inward lean to produce the centripetal force that takes the rider round the same bend as the bike. It’s remarkable how cyclists “get the knack of it” without knowing the mechanics.
Bike riding isn’t a job for the cerebrum. Maybe that’s why physicists can’t get to grips with it.
York, UK
<b>For the record</b>
鈥� We missed. Peter Godfrey-Smith, who presented evidence of octopuses throwing things, is in fact professor of philosophy at the Graduate Center, City University of New York (29 August, p 14).
鈥� When we referred to Earth’s first atmosphere we should simply have said that it would not support life (25 July, p 26).
Anonymity isn't as easy as that
You report Krzysztof Szczypiorski saying that as online data breaches continue people will start to use smarter ways to disguise illicit behaviour.
He observes that if people had adopted precautions such as email accounts under a different name, and prepaid credit cards that can be loaded anonymously, for example, that “would have saved a lot of people’s marriages” (29 August, p 10).
Thanks to stringent money-laundering regulations, as far as I know it is not now possible to legally obtain and use “prepaid credit cards that can be loaded anonymously” in the UK.
London, UK
Archery and out-of-body experience
Anil Ananthaswamy’s review of the book Kabbalah: A neurocognitive approach to mystical experiences (8 August, p 42) led me to wonder whether the world of sport might be ripe for investigations into the out-of-body phenomenon.
I can imagine that long-distance runners might experience the feeling of separation from their physical selves as they pound rhythmically mile after mile. From a personal viewpoint, I once had a fleeting moment of separation from my physical self while practising archery.
It came during a period of intense training when a combination of concentration and repetition made me feel as if I was observing myself going through the shooting process and it lasted while I loosed six arrows.
The central premise of Zen and the Art of Archery, first published by philosopher Eugen Herrigel in 1948, is that through years of practice a physical action becomes so effortless that you can perform complex movements without conscious thought. It might not be out-of-body, but it is part of the same continuum.
Stockport, UK
When is it time to be a gym bannee?
The idea that music has the capacity to raise people’s pain thresholds may explain why many fitness centres set exercise classes to music (8 August, p 10). In my experience, music in gyms is played extremely loudly, with the instructor shouting above it. Class members are there only for an hour at a time; but I wonder what damage is being done to the instructors’ hearing. Should they be protected?
London, UK
Handed festivals north and south
When discussing why Iron Age banquets might favour the right forelegs of pigs, you report Brian Hayden saying that “in many societies going sunwise is standard protocol in rituals. If you face the sun that means going from left to right” (15 August, p 12). This is true in the northern hemisphere.
The fact that the sun goes from right to left in the south presents an ideal way to test his theory: banquet rituals there would favour the left leg.
Were right legs favoured simply because people are generally suspicious of anything to do with left-handedness? Or is cutting off the right leg more natural for right-handed people: a butcher could tell us about that.
Sandy, Bedfordshire, UK
How to breed spermless boar
鈥� involves a second set of boars, gene-edited to prevent them from producing sperm. These would act as incubators of sperm from the set of boars with undescended testicles.
How to breed spermless boar
You write that the company Recombinetics has “disabled a gene essential for testicular development [in pigs]… the idea is that the company will sell semen with this disabled gene for farmers for use in artificial insemination” (15 August, p 10). So, er… how do you get semen from boars with no testicles?
Riverstone, New South Wales, Australia
How do bicycles stay upright?
This is the wrong question. It should read “How does a human stay upright on a bicycle?” The ability to cycle must lie in proprioceptive mechanisms, presumably centred on the inner ear, and our visual system, along with fine-tuned neuromuscular control.
Timsbury, Somerset, UK
Editor's pick: Does parenthood make us happier?
Georgia Grimmond asks whether parenthood makes us happier (5 September, p 40). But the studies she quotes are looking at the wrong group of people. Most found that the biggest increase in happiness was in parents over 40. Yet they didn’t take the next logical step to show that it isn’t children that make people happy, but grandchildren.
A grandparent can have all the fun of playing with children, but when they misbehave you just hand them back to their parents. Clearly we have children only so we can pressure them to have their own children, in order that we become grandparents and finally achieve happiness.
West Launceston, Tasmania, Australia
Mind isn't all about you, you know
How disappointing to find that Halligan and Oakley ignore fundamental evolutionary principles in their theory of consciousness. We know of no way in which the sense of self could have “developed for the benefit of the social group, not the individual”.
For a sense of self (or any other trait) to be present it must be of benefit to the individual manifesting it; of course it may also have spin-off benefits for other individuals.
The supposition that an adaptive strategy “could be beneficial to species survival” overlooks the reality that natural selection is not and cannot be a force promoting species survival.
But the authors’ conclusion, that consciousness “provides a powerful evolutionary advantage” by “extending each individual’s understanding of the world”, in fact fills the bill so completely that it obviates any need for the group-based and species-based postulates that precede it.
Camberwell, Victoria, Australia
Mind isn't all about you, you know
Your article on consciousness evolving for the greater good, not just the self, suggested to me that this needs a catchy name, like other consciousness models. How about the “newsroom model”: a coherent report of things that were decided elsewhere.
Coventry, West Midlands, UK
Mind isn't all about you, you know
It’s all very well for Peter Halligan and David Oakley to say that your unconscious mind tricks you into believing you have a sense of self (15 August, p 26), but what exactly is experiencing this self illusion?
Bath, Somerset, UK
Before the beginning…
It always surprises me that there are scientists who can’t accept that time and space began with the big bang (5 September, p 30). They succeed only in pushing the problem further back. You must accept either a beginning at some point or an infinite past, with all the horrors that infinity implies 鈥� everything possible has happened an infinite number of times. Infinity always spells the death of reasonable physics. I suppose we could all be whizzing infinitely round a closed loop, but that sounds just as bad.
Personally, I’ll stick with the good old big bang 鈥� everything has to start somewhere.
Walsall, West Midlands, UK
<b>First class post</b>
After the bees return, anti-environmentalists will say ‘You said bees were disappearing and now look!’
Steve Ridge to a crisis 鈥� in this case the crisis of bee die-offs (19 September, p 7)
Dry lands are not deserted lands
In your interview with Mike Mason about his plan to grow cacti on drylands for biofuel he repeats a common misconception: that semi-arid land has little use (15 August, p 25). This ignores the existence of over 500 million economically active land users in the world’s drylands.
The UN Food and Agriculture Organization estimates that drylands produce about a third of the world’s livestock products. And according to data held by the International Union for Conservation of Nature they are home to a third of its biodiversity. Land users in the drylands may need some more convincing about the merits of switching to cactus farming.
The fact that so much of the dry land is not covered by any legal title of ownership does not mean that it is freely available. We invite Mason to visit some of these people to learn more about the many different uses they already have for their land.
Gland, Switzerland
Editor's pick: Does parenthood make us happier?
You report that the happiness of older parents persists with increased numbers of children, unlike that of younger parents. If the surveys were conducted within the last decade, and asked parents only about their current situation, some of this may be the consequence of different generations having differing expectations of personal happiness.
The assumption that you deserve to have a job, children and material trappings is a comparatively recent one; older parents may have had lower expectations. For that matter, they may also have been better off.
Sawbridgeworth, Hertfordshire, UK