Editor's pick: The tautological measure of stuff
I think more is going on with new definitions of the “base” units in modern metrology than Stephen Battersby describes (3 October, p 38). Defining the metre in terms of the speed of light tells us that the metre per second, rather than the metre, is now the base unit. The proposal he describes for a new definition of the ampere will actually make the coulomb (charge) the fundamental unit.
That makes attempts to count electrons flowing in a circuit, with all their quantum uncertainty, seem rather misguided; would it not be better to measure charge directly, as we did at school using Millikan’s oil drop experiment?
Nettlebridge, Somerset, UK
Editor's pick: The tautological measure of stuff
Battersby shows an interesting, nearly tautological connection between units that depend on fundamental constants and constants that depend on those measured units. It would be good, though, to see more light cast on the candela, the unit of luminous intensity. Why is it tied to a monochromatic frequency? Real candles are polychromatic.
Hertford, UK
Editor's pick: The tautological measure of stuff
鈥� The candela is fundamentally tied to our ability to perceive light, and is defined with reference to the single frequency at which a standard eye is most sensitive.
Memory recovery and therapy
Doubtless there are some therapists guilty of instilling false memories (10 October, p 8). But it would be tragic if this occasional bad practice makes us doubt the value of psychological work and the need to listen to victims. The experience of church abuse shows that the pendulum of belief is firmly stuck in denial in many powerful quarters.
I am accredited with the and am also a solicitor involved with childcare cases. Ironically, I encounter a lot of false memories in my therapy clients. Frequently, they come to me with serious emotional problems but initially tell me they could not be anything to do with their “happy childhoods”. Over the next few sessions, without any pressure or suggestion, they will often disclose events in those childhoods which are clear examples of neglect or abuse.
In my role as a solicitor, I have the painful advantage of seeing intergenerational abuse and dysfunction. I frequently deal with parents who are in complete denial about their own childhood experiences, actually having no memory of it. However, also in the case papers is full evidence of the abuse that person suffered as a child, and which they are often now repeating and inflicting on their children.
London, UK
From Els van Ooijen, Psychotherapists and Counsellors for Social Responsibility
You misrepresent the work of psychotherapists. Rather than functioning as “mechanics” who apply a set of techniques, we aim to help people gain a deeper understanding of themselves and their problems. such as recovered-memory therapy. We also doubt that state regulation would be any more effective at preventing this than voluntary regulation.
Bristol, UK
Memory recovery and therapy
Most of this article relates directly to the 1990s. It cites old studies by Elizabeth Loftus about the creation of false memories. What does her contrived laboratory research tell us about somebody who has suffered years of abuse?
You promote a myth about hordes of therapists using “recovered memory therapy” after giving patients “strong tranquillisers” 鈥� but provide no evidence of even a single case of this happening. This unbalanced and unscientific witch-hunting colludes with the re-creation of a climate of disbelief over the scale of the child sexual abuse problem.
London, UK
Memory recovery and therapy
鈥� Our concern for real cases should not make us credulous about all past claims 鈥� especially those triggered by dangerous and outdated psychotherapy methods. The National Health Service records of Carol Felstead, whose death in the UK we discussed, show that she was at times “heavily sedated” on diazepam during psychotherapy sessions. And Elizabeth Loftus works on: in 2013 she implanted memories in people with “highly superior autobiographical memory” ().
<b>First class post</b>
But… this technique is practiced by medics with nothing more than a gloved finger
Deborah Buffalin on a machine to estimate due dates (31 October, p 16), ending: “But, yay, technology.”
Technology for keeping interest
Manfred Spitzer claims that information technology is of little or no use in education (17 October, p 28). I suggest that he checks out the subject in more detail with actual examples. As a secondary school teacher 25 years ago I had a physics class of not-very-interested 15-year-olds who would have their bags packed up 5 minutes before the end of the lesson. Looking at force, acceleration and gravity was not going to enthral them but it was on the exam syllabus.
My technician told me to use the computer. Sceptically following instructions, I put the most awkward lad in charge. That lesson was vibrant with lots of “What would happen if…” It got them interested in the topic and wanting to go further. I had to throw them out at break time.
Halstead, Essex
Do people have children to fit in?
Your article on having kids does not take into account one crucial factor contributing to happiness: fitting in with your peers (5 September, p 40). My grandmother, talking about the war, used to say: we were poor but it didn’t matter, because everybody was. My aunt once stated that she eventually decided to get married because all her friends had. That’s not mere copycat behaviour: it expresses the need to share similar lifestyles to avoid being left out.
I would guess that an extra reason why 15 to 19-year-olds are the least happy to have children is because most of their peers have none. People over 40 are the happiest, because most of their friends have families. To our social species, no one wants to be the odd one out.
Parma, Italy
Einstein's proof of general relativity
Pedro Ferreira says that the first “proof” of general relativity was Arthur Eddington’s observation of gravitational lensing in the 29 May 1919 eclipse (10 October, p 33).
But in November 1915 Einstein calculated the anomaly in the precession of the orbit of Mercury, which had never been explained by conventional gravitational theory. When Einstein found that the result of his calculation agreed exactly with observational values he told one of his colleagues he had heart palpitations. This was the moment he knew for the first time that his theory was correct.
Nottingham, UK
Solutions that distract politicians
While Tim Flannery’s “Here comes Plan C” (10 October, p 24) inspires optimism that more new ideas and possibilities for combating climate change are continually being advanced, there is also pessimism at the realisation of how our national and world leaders will receive the notion. Will his proposals not vindicate their assertions that those clever scientific bods will inevitably find some smart way around climate change, so we can comfortably proceed with business as usual, ignoring all the loonies and lefties who are predicting disaster?
In the UK we are beset with politicians who are not only leading the race to frack for methane, but who apparently believe that we are already making enough energy from the wind. We need to stop consuming fossil fuels as soon as we can, and anything that diverts our fickle politicians’ attentions away from that is basically a bad thing.
Kirkby Malzeard, North Yorkshire, UK
Definitely not maybe finding oil
As a petroleum geologist engaged in the search for oil and gas, I was encouraged by David Deutsch’s words that “the awful secret at the heart of probability theory is that physical events either happen or they don’t: there’s no such thing in nature as probably happening” (3 October, p 30). When we plan to drill for oil or gas, management require an estimated probability of success (POS) between 0 and 1.
We concoct POS values based on combining the chances of a number of favourable geological factors existing simultaneously. I always felt that we either would find oil or gas, or we wouldn’t. Yet this logic would be frowned upon as unscientific or just laughed at. I feel vindicated.
Bradford-on-Avon, Wiltshire, UK
Greengrocers' ire if you follow this
Oh dear, oh dear, Gregory Laughlin: you must have caused great consternation among the purveyors of fresh fruit and vegetables. You said that squeezing an object is a handy way to learn about its insides, likening this to testing a melon for ripeness (19 September, p 37).
The right thing to do is to hold this fruit in the palm of one hand and tap lightly with the fingers of the other hand. If it makes a “hollow” sound it is ripe.
Do not squeeze with fingertips: the small pressure points cause bruising 鈥� and shouts of rage from the vendor if you are spotted!
London, UK
Counterintuitive bicycle experience
David Boswell shifts focus from machine to rider when describing how to stay upright on a bicycle (Letters, 26 September). Years ago, an infection substantially affected my inner ear function. Later, improved yet still impaired, I cautiously attempted to ride my bicycle. As if by magic, all sense of impairment vanished. I realised then that inner ear function plays no role in controlling a bicycle. The useful cues are visual.
The inner ear by itself cannot tell whether you are on a corner. This is analogous to a pilot’s need for an artificial horizon in cloud.
Concord, California, US
For the record
鈥� Too chilled out: we meant to refer to “frozen carbon monoxide” on the surface of Pluto (17 October, p 6).
鈥� Some figures we gave for global production of lithium were for the gross weight of compounds in which lithium is contained: the true weight of lithium extracted in 2013 was 31,300 tonnes (17 October, p 38). And Antofagasta is 350 kilometres to the west of the Salar de Atacama.