Irrational decisions
The loss aversion that dogs our ability to deal with climate change as George Marshall describes (16 August, p 24) is documented by Dan Ariely in the book Predictably Irrational.
Ariely shows that students who are given free rein over when to submit work generally do worse than those given deadlines spaced throughout the semester, because they prioritise other work until the last minute. Approaching climate change in the same way will only end in disaster.
Due to the inherently slow response of the climate system, mitigation strategies will take tens to hundreds of years to have any effect, something that is often overlooked.
However, Ariely also shows that those given the opportunity to set their own deadlines are proactive in meeting them.
Southampton, UK
Irrational decisions
Daniel Kahneman’s research into people’s aversion to the facts on climate change, quoted in Marshall’s article, sets the tone for much of the debate that occurs around this topic. Marshall distils it to “sacrifice now for benefit later”. This indicates a type of bias that affects much research in sociology and medicine, where we only look for responses to issues presented as problems.
Fortunately, there is now a trend in medical research to examine what makes people healthy so we can treat disease better. Perhaps more attention could be paid to what makes people happy to live in a more sustainable way.
St Albans, Hertfordshire, UK
Uncommon ancestor
Michael Le Page tells how all life on Earth derives from LUCA, the last universal common ancestor (16 August, p 30).
It seems odd that life originated only once. Why has a different biochemistry not begun to evolve in parallel during all these billions of years? Was the emergence of prokaryotic and then eukaryotic cells so vanishingly improbable that the chance has not recurred?
It seems likely that other workable biochemistries are possible. Is it possible to put numbers to these evolutionary probabilities? Doing this might indicate something about the chances of life existing elsewhere in the cosmos.
Oxted, Surrey, UK
Uncommon ancestor
鈥� There has been a lot of speculation about this. LUCA is widely thought to have been the amalgamation of various proto-biochemistries, and most researchers are open to the idea of a “second genesis” 鈥� multiple independent origins of life that were outcompeted by life as we know it. And many researchers think other biochemistries are probably clinging on somewhere, but we don’t know how to recognise them.
Young blood
Helen Thomson writes that transfusions of young blood may help treat age-related conditions such as Alzheimer’s and heart disease (23 August, p 8).
Given that there are about 2 million blood transfusions in the UK every year, and that the blood services and hospitals keep detailed records, could the research benefit by analysis of this existing data?
There are a large number of variables, but even if only the transfusions that were required for a physical loss of blood were considered, there should still be a huge number to work with.
Oxted, Surrey, UK
Young blood
鈥� There is a lot of blood swapping going on, but the benefits of young blood are likely to be transient, making any effect difficult to measure retrospectively. In addition, uncovering the age of existing donors may be difficult.
Dangerous water
Stephen Ornes’s article about rogue waves suggested that up to half of these waves result from “crossing seas” in which wave trains from different directions interact (26 July, p 42).
In the early 1980s, my research student Chris Machen conducted experiments in a wave tank at Newcastle University capable of generating crossing waves.
The tank shallowed towards one corner so that deep-water waves (albeit only 150 mm high) began to break as they approached the shallow corner.
Whereas the crossing waves never increased beyond their combined height in “deep” water, they often exceeded that considerably when breaking.
Such a situation might be expected to occur on continental shelves, as suggested by the map of incidents accompanying Ornes’s article.
It might also happen at the entrance to harbours when direct storm waves cross those reflected from neighbouring sea walls, thereby introducing an unexpected additional hazard when least welcome.
Whitwell, Isle of Wight, UK
Dangerous water
In your article on rogue waves, I was astonished there was no mention that negative peaks exist as well as positive ones.
Such rare, huge troughs might be more dangerous than waves of similar magnitude and would be more difficult to spot from the deck of a vessel. This might explain the lack of observation and the ignorance of such phenomenon as a consequence, even though they must be as frequent as the rogue waves.
Thirty years ago, a marine officer mentioned to me that such “holes” not only exist, but might have been the cause of ships’ disappearances.
Some sailors navigating far south, in the latitudes around the “furious fifties”, have also reported observing “towers of water”, perhaps the result of two rogue waves running into each other.
Genolier, Switzerland
Staying power
George Wadsworth makes very valid points about the need to use all alternatives to generate electricity for the world’s poorest people (23 August, p 28).
These alternatives need to be maintainable by those communities or they will eventually fall into disrepair and discredit future efforts.
Remote villages may have no skilled technicians able to repair solar systems, and villagers may be unable or unwilling to pay for a technician to travel from a large city. Even if there is someone to do repairs, what about the cost and availability of spare parts?
Local government structures may not exist to organise maintenance, and remote officials may have little interest in serving distant communities.
Power systems for poor communities outside major towns need to be maintainable with the financial and technical resources available to those communities for the lifetime of the equipment.
Melbourne, Australia
Put the diet on ice
As well as tackling autoimmune disorders such as type 1 diabetes (23 August, p 26), consciously raising the activity of your sympathetic nervous system could be used to combat obesity.
Since 2009, there has been renewed interest in the possibility of stimulating brown adipose tissue to burn fat. Repeated exposure to cold 鈥� used by people in the article to fire up their nervous system and subsequently suppress their immune systems 鈥� seems to activate and increase the capacity of this tissue to burn fat.
There is some evidence that repeated exposure to mild cold causes weight loss in humans, but unsurprisingly, people who are overweight may not enjoy repeated exposure to severe cold.
The downside of raising sympathetic nervous system activity in this way is that it is associated with an increased incidence of heart attacks and strokes.
Regulatory authorities are unlikely to approve drugs for obesity if they increase the incidence of heart attacks, but they cannot control how we breathe, expose ourselves to cold or meditate.
Nonetheless, we should know both the benefits and risks of these techniques.
Welwyn Garden City, Hertfordshire, UK
Heart in your mouth
Congratulations to Jon White for an excellent article examining the mixed health benefits of saturated fat (2 August, p 32).
However he seems to have missed a further meta-analysis. It was noted that Japanese people on a low-fat diet experienced a low incidence of heart disease, as did the French who enjoyed a high-fat diet. Yet the British, Americans and Australians on a medium-fat diet suffered a high incidence of heart disease.
The conclusion must be that speaking English is bad for you.
Darwin River, Northern Territory, Australia
Dying with dignity
You report on the growing number of people from the UK, especially those with neurological diseases, going to clinics in Switzerland to end their lives (23 August, p 7).
One reason might be that many people worry they will have a painful, undignified death. Some relatives remain traumatised after seeing their dying husband or wife screaming for help to ease their suffering.
The Royal College of Physicians says there is a lack of palliative care in hospitals, particularly at night and weekends. Hospices relieve pain, but there aren’t enough of them.
No wonder there are calls for doctor-assisted help to die. It seems the UK authorities want to keep control, and won’t allow patients to choose this option themselves, thus driving people to the Swiss clinics.
London, UK
Pythagoras uncut
I am not sure whether I am more surprised by Guy Cox’s revelation that you needed to submit to the distinctly un-Greek custom of circumcision to be admitted to the library of Alexandria, founded around 280 BC, than I am to read that it applied to Pythagoras, who passed away some 200 years earlier (9 August, p 29).
Penarth, Vale of Glamorgan, UK
Cosmic tangles
Anil Ananthaswamy describes a thought experiment in which three electrons behave as if they were linked in some way, without their having been entangled artificially (2 August, p 8).
This experiment has not yet been performed, but remote correlations between non-entangled photons were demonstrated in 1956 by Robert Hanbury Brown and Richard Twiss. They found that photons of the same frequency, arriving at two telescopes about 6 metres apart, were correlated when both telescopes were pointed at the same bright star.
However, this correlation is distinct from that in the article, as it can be understood in terms of classical electromagnetic theory.
Cucuron, Vaucluse, France
On deaf ears
Your article on health concerns surrounding eating wheat misses an important point (12 July, p 28).
Fad dieting is problematic not because of scientific controversy over whether non-coeliac gluten sensitivity is over-diagnosed, but because people don’t heed science at all.
In particular, they don’t bother to consult a doctor about their symptoms before removing gluten from their diets. People are queuing up in their droves to go gluten-free, but not to have colonoscopies.
Houston, Texas, US
A pilot's best friend
For passengers to feel safe, it seems we need a human presence in the cockpit (9 August, p 30).
This brings to mind the back pages of Flight magazine at least 20 years ago, when arguments began about whether two pilots or one were necessary.
“In future, the cockpit will contain just one pilot and a dog,” one commentator wrote. “The pilot will be there to feed the dog. The dog will be there to bite the pilot if he touches anything.”
Longhope, Orkney, UK