Password to life
Paul Marks refers to a TV drama in which a fictional character is killed by hacking into their pacemaker (8 November, p 19). He then explains how security experts are engaged in making it harder to reprogram medical devices, just in case anyone should want to do this for real.
In the real world, murder is infrequent, incompetence is everywhere and risk-averse computer security policies are a recurrent irritation. One might wonder whether hypothetical hackers are the right problem to be concerned about.
Nowhere in the article is there any mention of how many people have already died because no one could find the login credentials for their medical devices in an emergency. Do we really want to make this more difficult?
Saint Louis, France
For the record
鈥� We got the name of one of the two founders of the Bill and Melinda Gates Foundation wrong (25 October, p 40). Sorry.
鈥� We should have credited the launch of the OpenWorm project on Kickstarter to the community of researchers at including Stephen Larson (29 November, p 21). Independent researcher Tim Busbice used OpenWorm data to create his robot.
鈥� Our report about internet companies being blamed for hampering the security services (29 November, p 6) should have got the name of the executive director of the Open Rights Group correct. We believe his MI5 file is in the name of Jim Killock.
Dangerous tritium
The article discussing the possibility of generating energy using small-scale nuclear fusion suggested that both deuterium and tritium are stable isotopes of hydrogen. Although deuterium is a stable isotope, tritium certainly is not (8 November, p 9).
It is a low-energy beta emitter with a half-life of 12.3 years. It decays to helium.
Further, tritium is very dangerous because it can incorporate easily into skin and into bodily fluids.
Eastbridge, Suffolk, UK
Love is blind
Helen Thomson writes of a man who has a delusional belief his wife is an impostor, because the emotional processing in his brain does not match his visual processing (8 November, p 12).
This dramatic and moving example illustrates the irresistible triumph of emotion over the insurmountable evidence of the senses.
It is frightening and gloomy to see how difficult this makes it for the species to do the right thing.
On the other hand, it is the same mechanism that allows me to avoid despair and believe that my grandchildren will muddle through climate change, corporate greed, governments and our other legacies.
Toronto, Ontario, Canada
Moral code
鈥� The does seem to be different at different speeds. We will return to this.
Moral code
I find it hard to believe your assertion that running and walking at 6 kilometres an hour both burn the same number of calories, while dispelling myths about fat (15 November, p 32). My intuition forces me to think that there must be a difference in energy expenditure of two such different modes of locomotion. When running, the body is being propelled into the air against the force of gravity; when walking, one foot remains firmly on the ground at all times.
Southampton, Hampshire, UK
Moral code
鈥� Something else that we didn’t have space to mention is that “gay gene” carriers in both sexes have another trait in common: they are strongly attractive to men (23 August 2008, p 7).
Walking and running
Moral code
Andy Coghlan reports a study of gay brothers that provides further strong support for the genetic basis of homosexuality. (22 November, p 11). There are, however, two counterarguments to be addressed before it can be accepted.
The first is that any gene that reduces the chance of the person carrying it reproducing should, over time, disappear from the gene pool. The second is that identical twins do not always share the same sexual orientation.
Both arguments can be addressed if the expression of the genes involved is triggered randomly during development of the embryo, not at conception. Say these genes give a 1 in 5 chance of being homosexual. They would still need to compete with variants. The “gay gene” would conceivably, therefore, have to provide a reproductive advantage. This might be connected with close relatives’ reproductive success.
Ruislip, Middlesex, UK
Moral code
Your leader on the moral implications of homosexuality being partly or largely biologically determined did not address one counterargument (22 November, p 5). There are other desires or traits that are, in all probability, largely biologically determined but which no modern society can tolerate. Why should societies forbid the practice of some desires but not others?
The answer is surely that some practices cause harm but others do not. Most readers of 快猫短视频, I suggest, do not regard the practice of homosexuality as harmful. Others may feel that its practice degrades society or even consigns perpetrators to hell, but it may be a sense of disgust that motivates such arguments. As you conclude: “Get over it.”
During my lifetime, the society in which I live has come to reject arguments based on religion and accept the great harm caused by forbidding homosexuality.
Welwyn Garden City, Hertfordshire, UK
Screened from harm
Clare Wilson suggests that screening for breast cancer may do more harm than good (15 November, p 14). It is not the screening that does the harm, but what is done with the information gained from it. If a group of women who are screened have worse health outcomes on average than those who aren’t, the wrong action is being taken as a result of the screening.
If a new approach was taken, which was to treat unequivocal cases of advanced tumours in women who are too young to simply outlive the tumour and ignore the rest, it would surely be impossible to argue that screening was worthless.
This would not be optimal: we need to find the best compromise. To stop screening because it leads to unnecessary treatment in some cases would be no better than banning antibiotics because some doctors overprescribe them.
Rayne, Essex, UK
Spot the difference
I suspect that the key question about a multiverse (27 September, p 32) is not whether multiple universes exist, but whether the difference between them is as small as the spin state of a single electron 鈥� or so great that mathematics itself is useful only in ours, and does not apply in others. (Or, of course, something in between.)
Auckland, New Zealand
Collapse in doubt
Petros Sekeris may have chosen an unfortunate example to illustrate his hypothesis about violent responses to resource depletion (22 November, p 30). Jared Diamond’s analysis of events on Easter Island is open to question.
There is a case to be made that, despite depletion of many resources, Easter Islanders had managed to create and maintain a stable society. That society then collapsed as a consequence of visits from the outside world.
Not only did the islanders discover they were not alone in the world; they suffered from introduced diseases. The final indignity was the forceful expropriation of their land and the introduction of sheep. Scots might sympathise.
Watch Earth society collapse when an alien civilisation arrives, with previously unknown diseases and hordes of creatures to consume our limited resources.
Stirling, Western Australia
Tractor production
David Sanderson points out that farm machinery uses a lot of oil (22 November, p 34). I read of a solution to this in Meccano Magazine 鈥� standard reading for the technically aware schoolboy of the 1950s.
It was to provide electric power by overhead cable to the corners of fields. The electricity would be fed to vehicles by armoured cables that would be laid out on the outward ploughing run and wound in on the return.
I think it was the Central Electricity Generating Board that demonstrated prototypes, aiming to replace imported oil with home-dug coal firing power stations. It was not followed up, for the usual reason of the time: “lack of export potential”.
Newcastle upon Tyne, UK
Heartless killers
Brilliant, another way to kill each other, with autonomous robots (15 November, p 38). But they can’t be too effective as that would be wrong. What makes a robot that is good at killing people illegal and amoral, but a robot that is less effective but still manages sometimes fine?
Why don’t countries hold some sort of contest to settle their differences instead? This could be sporting, or even something like finding the most effective cure to a disease.
Kirkton of Kingoldrum, Angus, UK
Burn the midnight oil
Paul Younger seems to base his opposition to divesting from fossil fuels on a fundamental misunderstanding. He repeats the error that the divestment movement is “premised on the idea that fossil fuels can be abandoned immediately”.
This is simply not the case. The spearhead of the divestment campaign, , calls for a wind-down period of five years, and an immediate freeze on new investments in what it calls the 200 worst offending companies.
A quick look at the proposed Intergovernmental Panel on Climate Change carbon budget to keep global warming below 2 掳C, alongside the fossil fuel reserves held by the industry, is enough to see that the two aren’t compatible.
Canberra, Australia
Burn the midnight oil
Tim Ratcliffe’s vision of stopping investment in fossil fuels and artificially imposing a transition to a low-carbon economy would have downsides (15 November, p 26). It might slow the growth of knowledge, delay discoveries and lead to greater overall damage to the climate. Fossil fuels can be both the cause of and solution to our climate change problems.
Every barrel of oil we burn buys us new knowledge. This will eventually allow renewable energy technologies to naturally displace heritage technologies. Until that time perhaps we should respect the wisdom of markets and put economic growth first.
Leixlip, County Kildare, Ireland
Support staff
In reply to Adrian Ellis’s letter, you comment that the development of an industrial civilisation might be predicated on a “critical mass of people” (15 November, p 30).This reminded me of a 快猫短视频 interview with David Suzuki in which he was asked how many people our planet could support (15 October 2008, p 44).
He relayed the estimate by an unnamed Harvard scholar of “200 million if you want to live like North Americans”. I wondered then whether 200 million would be enough people to produce for themselves all the features of life they would wish to retain.
Our species may be a long way from worrying about having too few members, but has anybody addressed population questions from this point of view?
Manchester, UK
Screened from harm
鈥� No one proposes that we stop screening entirely. Unfortunately we lack reliable methods of discriminating aggressive tumours from others 鈥� and, if such methods existed, women diagnosed with non-aggressive tumours would need to have quite remarkable confidence in them.