Selling sex
There will doubtless be many antagonistic responses to your interview with Laura Agustin, but I say “hoorah” for her views on prostitution (6 July, p 25). Anyone can sell all sorts of body-based services, but only the sale of sex is considered to be wrong.
This simply boils down to the idea that sex is somehow morally dubious. We have to throw off the religious attitude to sex, which means that as a bodily pleasure, it has to be wrong and sinful, and so made a source of guilt, and an activity that must be controlled and limited by both religion and the state.
No, it mustn’t. Much good and little harm will be done if governments and religions stay out of people’s sex lives.
Power struggle
Caroline Williams discusses the possible use of smart meters to enable power companies to control customer appliances when demand exceeds supply, and the alternative self-sufficient “community” grids which use local storage (22 June, p 38). Also worth considering is the use of dynamic tariffs based on the real-time price of wholesale electricity.
With substantial renewables, which typically generate power intermittently, prices will be higher during shortages and lower during surpluses. Weather forecasts could help predict total intermittent output and so, by adding data about demand and the availability of non-renewable power, prices could be predicted too. This would enable better local decisions, possibly removing the need for smart meters and the “big brother” issue of utility companies controlling our appliances. It would also reduce the need for costly local storage.
In South Africa electricity is often used for hot water systems. For years manufacturers there have had to incorporate a ripple switch in all such systems. These are controlled by the frequency of the electricity supply. The electricity company, can, by altering the frequency of supply, remotely switch off all such appliances. This is safe and fairly hassle-free.
Barton on sea, Hampshire, UK
Williams makes distributed renewable energy generation sound attractive, while acknowledging the challenges of storage and cost. A better solution may simply be to use less energy while keeping the efficient, centralised generation and grid.
Christchurch, New Zealand
Free code
In his look at computer programming, (8 June, p 36) Michael Brooks omits a branch of languages: the “English-like” ones of which LiveCode, by RunRev in the UK, is the foremost. Recently made open-source, anyone can access its coding, and its programs will run on any platform. It is easy to learn and memorise.
Steam power
Stuart Clark’s alternative moon-formation theory based on a massive natural explosion inside Earth was intriguing (6 July, p 30). It made me wonder if a self-propelling planet could exist somewhere. It would need a less explosive but still significant heat output from a natural, internal nuclear reactor, and to be near enough to a reservoir of the right propellant 鈥� a nice deep ocean, say.
That planet would be a lonely wanderer that had escaped from its parent star, powered by a nuclear steam engine. Worryingly, budding Darth Vaders may not have to bother building a Death Star 鈥� they could just grab one that nature made earlier.
Born to breed
Fred Pearce repeats the suggestion that “we are most likely heading for peak population by mid-century” (6 July, p 42). This ignores the effect of evolution: when the environment changes, species change to maximise reproductive effectiveness.
In the past it was only necessary to form a sexual partnership and children would probably arrive. Now, reliable contraception means that people who actively want children have many more than people who don’t.
If this continues, then the great majority will be descended from those who wanted lots of children. Assuming that the desire to have lots of children is at least partly genetic, they will inherit this, and the population will continue its inexorable rise.
Donor barriers
The complex biology of cancer’s development from primary tumour to metastases was excellently described in your story (22 June, p 6), highlighting exciting research to improve the outlook for future patients. It also opens the debate on the donation of tissue at very sensitive times for patients and their families.
As an independent group adding an informed patient perspective to cancer research in the UK 鈥� including work with key tissue banks 鈥� we see an urgent need to raise awareness of the value of human tissue, blood and other health data in such research.
Often, we find great interest and enthusiasm to donate, and anger that tissue has been or is stuck in tissue banks due to complex regulatory and pseudo-ethical hurdles. The main reaction from patients or their next of kin is to wonder why they weren’t ever asked for consent to use such tissue in research.
This is mainly down to doctors “protecting patients” or their families at times of stress. We’ll carry on working with doctors to reduce unnecessary barriers.
Spy story
Anti-terrorism vigilance as a result of misinterpretation extends beyond journalists with invoices for articles about chemical weapons in Syria (Feedback, 15 June). I am an academic, but also a novelist under my pen name, Lior Samson. After my techno-thriller Web Games was published in 2010, for many months I could not fly from or within the US without getting “SSSS” printed on my boarding pass, an indication that I had been singled out for extra checks, including pat downs.
I had based the novel on software that I designed in 2003, which bore similarities to the computer worm Stuxnet. After the Stuxnet expos茅 in 2010, I regularly corresponded with industrial security experts, one of whom in Germany assured me that our exchanges were monitored by intelligence services. Eventually, they seem to have realised it was fiction, as I can now get through airport security without being pulled aside.
Calcium deposits
I agree with Robert Gaines and Shanan Peters that if calcium and silica became more bio-available as unusually large amounts of rock were eroded, it could have prompted the Cambrian explosion in complex life forms (15 June, p 30).
Levels of calcium minerals would have been so high that organisms had to find ways of removing them from their biochemical systems. Useful deposits such as spines, bones or shells would surely give an advantage. A similar argument can probably be made for silica.
Additionally, could the carbon dioxide levels required to thaw out “snowball Earth” have been high enough to cause the melting that would be required for such rapid erosion?
It takes two
We don’t need the many-worlds interpretation of quantum theory (newscientist.com/article/dn9930). Its prediction that a single universe splits into two when a quantum measurement is made is indistinguishable from a pair of universes that evolve identically up to that point, and then diverge. If the cosmos is truly infinite, that second explanation seems more natural.
Therefore, the result of a quantum measurement does not tell you which universe you have “split off into”, but rather which one you have been in all along.
Read my lips
You discuss the need to create a new language of gestures to interact with computers (25 May, p 40), but if movement-sensing cameras are now sensitive to 1 millimetre, would it not be easiest to use lip-reading?
At the third bleep鈥�
The Feedback article on the zero per cent power-setting on a microwave oven chimed with me (18 May). My manual specifically refers to this as a way of using the oven as a kitchen timer.
Dark words
Letter writer Stephen Rowe is right to be confused about the use of the phrase dark energy (15 June, p 33).
It is not a very good name to explain the observation that the expansion of the universe is accelerating. On the other hand, “anomalous acceleration” just doesn’t have the same ring to it.
Who said that?
The views of Lady Randolph Churchill are quoted in The Last Word on the subject of nations that boast most Nobel prizewinners (29 June): “We owe something to extravagance, for thrift and adventure seldom go hand in hand.” How does this compare with “necessity is the mother of invention”?
Sequence of time
It is silly of (some) physicists to claim “there is no time” (15 June, p 34). Physicists, like the rest of us, experience life sequentially: they are born, grow up, die, read this line before the next.
If mathematical physics does not recognise sequence, well, so much the worse for mathematical physics. As for mathematical physicists, they can stew in their own mathematical juice.
For the record
鈥� We veered slightly off course in our look at citizen cartography (6 July, p 20). Kenya’s Map Kibera was a project of the GroundTruth Initiative, not the Humanitarian OSM Team.