Too much salt?
I tend not to read my copy of New 杏吧原创 in page order. As a result, I came across your article about medical myths (12 February, p 40), which stated that “it’s not just tabloid newspapers that misrepresent medical statistics for dramatic effect”, before the “Insight” column (p 11) about employing “taste bud trickery” to cut salt intake in the US.
The second article states that “the average American eats 3500 milligrams of sodium a day”. Given the first article’s suggestion that people find large numbers much more alarming than smaller ones, I wonder what was wrong with using 3.5 grams all of a sudden?
The editor writes:
鈥� The American Heart Association report cited in the article about cutting salt intake used milligrams and we, perhaps ill-advisedly, followed suit. We introduced a more clear-cut error in our picture caption, which should have said that the average American eats 3500 milligrams (or 3.5 grams if you prefer) of sodium (not salt) a day.
Mad cow count
As a member of the team from the Agricultural Research Service, part of the US Department of Agriculture, that confirmed and genotyped all the US cases of BSE (mad cow disease), I would like to offer a couple of corrections to your story about the demise of the disease (29 January, p 6).
There have been three reported BSE cases in the US, not two as you reported. The first, in 2003, was in a cow from Washington, followed in 2004 by one in a cow from Texas. The third case was in a cow from Alabama which showed for the first time a genetic form of BSE, which was proven to be passed on to offspring.
Your suggestion that “BSE [is] almost eradicated” is inaccurate. BSE can never be truly eradicated because the genetic form exists. Its discovery lends support to the theory that the BSE outbreak in the UK originated from a genetic form of the disease and not because scrapie, the similar disease in sheep, jumped species.
The editor writes:
鈥� It is accepted that “atypical” cases of BSE will continue to occur from time to time, in the same way that sporadic Creutzfeldt-Jakob disease (CJD) does in people. But our investigations revealed that atypical BSE is considered unlikely to ever be identical to classical BSE, or transmissible to humans as CJD. This means that the very specific, classical strain of BSE is unlikely ever to re-emerge.
Population problem
I cannot understand why the doom-laden reports about limited resources I read in New 杏吧原创, such as your recent interview with Lester Brown (5 February, p 27), never spell out the blindingly obvious cause of impending global calamity: overpopulation.
I realise that spelling this out is politically incorrect, but when things are so serious we should not be coy. The Chinese took the bull by the horns and successfully reduced their birth rate; the reason their population has not yet stabilised is that they simultaneously increased their standard of living and hence their longevity. The rest of the world condemned China for infringing human rights. But is it not better to have one child per family than to starve?
Admittedly, to carry out such a policy quickly requires bureaucratic coercion, but there are more acceptable longer-term approaches, based on education and contraception. What are we waiting for?
The editor writes:
鈥� For an exploration of the effects of a growing population on global resources, see our special report on population (26 September 2009, p 34).
Dark matter belief
As a non-believer when it comes to dark matter, I was disappointed by your biased article on the subject ( Instant Expert, 5 February). Dan Hooper gave the impression that evidence for dark matter is all around us. The small column “Did we get gravity wrong?” gave a different explanation for the higher-than-expected speeds of stars around galaxies. But this one concession to “modified Newtonian dynamics” (MOND) is not enough to give a balanced view.
Just because MOND does not always provide the right result under all conditions does not mean that the basic idea is wrong. Remember that support for the existence of dark matter is based on discrepancies between visible mass and its gravitational effects, or on cosmological models which are full of assumptions.
One could equally well argue that all the evidence points to the conclusion that dark matter does not exist. After decades of intensive searching, not one dark matter particle has been observed, and even the Large Hadron Collider at CERN in Switzerland has so far provided no indication of its existence. To me, the most plausible conclusion, based on the experimental evidence, is that dark matter does not exist. That many people believe in the stuff does not make it scientific.
Compossibilites
Brian Greene explains the “many worlds” interpretation of quantum mechanics (5 February, p 30) by stating “if quantum mechanics predicts that X, Y and Z are possible, with different probabilities, then X, Y and Z will actually happen. All possible outcomes occur, but in different universes.”
This implies that the interpretation might ignore what the philosopher Gottfried Leibniz described as “compossibility”. Leibniz pointed out that it is possible for me to be standing, sitting or speaking. While I can be standing and speaking at the same time, or I can be sitting and speaking, I cannot be both standing and sitting. The first two pairs of possibilities are, according to his theory, “compossible”. The third is not. He believed that the universe we live in is the “most compossible”.
Leibniz kept the theory secret in his lifetime to avoid accusations of atheism, and instead publicly promoted the “best of all possible worlds” idea that was famously attacked by Voltaire.
In order to be sure that X, Y or Z will actually occur, we must be sure that they are compossible with everything else, and that all events leading up to them have also been compossible.
Ancient encryptions
You report that software manufacturers are moving towards the use of full-disc encryption to protect computer data (29 January, p 17). It has in fact been a standard part of the Linux operating system for at least two years. It works by encrypting information on parts of the disc using a password, which is supplied when the computer boots up.
However, this does not protect laptops that are carried around in a hibernated or stand-by state, because the password is only requested when the computer starts up. The disc remains accessible until the machine is shut down and rebooted. I imagine this would be the same for any operating system-based encryption scheme.
Elementary
Having read your interview with David Ferrucci of IBM about the company’s Watson supercomputer, and having seen a picture of it, I am utterly unimpressed by the fact that it competed on the quiz show Jeopardy! (12 February, p 27). What is so “super” about a computer that can beat two humans if it is the size of a living room and consumes 4000 times the power of a human brain?
Please IBM, spare us your Watson. I look forward to seeing Holmes, instead.
3D dogs
Feedback recently asked for evidence to support the idea that some dogs have better spatial awareness than others (12 February). This immediately caught my attention, because of a simple experiment I once carried out on a couple of dogs: the first a Labrador retriever, the second a German shorthaired pointer.
In turn, I took each dog into a wood and got it to “stay”, then walked out of its sight, climbed 1 metre up a tree in a clearing and called the dog. The first dog looked around for me at dog eye level, increasingly desperately, for a couple of minutes. The second entered the clearing and immediately spotted me.
Both dogs were working gun dogs but, as canine aficionados will know, retrievers mainly work with game already on the ground, while pointers also have to spot quarry in the air, introducing the important third dimension.
While it is true that there aren’t any differences in the number of dimensions dogs move in- Labradors spring up to greet you as enthusiastically as any other breed, after all- they almost certainly do vary in their ability to process information in more than two dimensions.
Beer paradox
John Peisley complains that his beer has become less affordable, as its price has increased 32-fold while his salary has only gone up by a factor of 13, from 拢4000 to 拢52,000 (19 February, p 31).
In 1972 my salary was 拢1000; now it is 拢42,000. Following Peisley’s reasoning, I should find beer more affordable now, since my 42-fold increase in salary is greater than the corresponding increase in the price of beer.
My starting salary was lower, my finishing salary was lower, and my increase over the years has been lower. Yet it seems beer has got cheaper for me but more expensive for my higher-paid peers. Amazing!
What's in a name?
In response to Alan Chattaway’s call to name the phenomenon of something being known more widely by an erroneous name than by its correct one (29 January, p 25), I would like to suggest “hoovariation”.
The number of times I have heard people incorrectly refer to their vacuum cleaner must be inversely proportional to the number of people who actually own a Hoover.
Brain buster
I think we should be careful about constructing maps of our brains (5 February, p 32). I remember a science fiction story, I think by Arthur C. Clarke, about a team of neuroscientists who worked for years to construct a highly accurate map of brain functions.
When the leader of the team eventually came to contemplate the finished product, he became locked in a feedback loop, with his brain thinking about his brain thinking about his brain…
He then had to be carried away, frozen into immobility. A warning to the curious, perhaps.