Letters archive

Alex Berezow and Hank Campbell are correct to claim that progressives can be selective in their use of science (2 February, p 24) , but in making a muddled distinction between science and ideology, they fall into the trap they criticise in others. Take their example of genetically modified crops. Scientific hypotheses about GM crops …

Given talk of Republican resistance to tackling climate change, it is ironic that a large proportion of the emissions cuts President Obama has pledged to make (2 February, p 10) will be met by private-sector fracking initiatives, opposed by a caucus of Democrats, and California state policies initiated under a Republican governor, Arnold Schwarzenegger. As …

You report a proposal to reverse global warming by seeding the atmosphere to reduce cirrus cloud cover (26 January, p 14) , but you do not address the assumption that cirrus has a warming effect . Whether or not it does may depend on the shape and size of the ice crystals in these clouds. …

Your editorial rightly decried the National Rifle Association's "strangling of research" on US gun violence as "utterly reprehensible" (26 January, p 3) . As recognised in a 2005 US National Research Council report, there is a need for better firearms data and deeper investigation of the causal relationships underlying gun violence. But there is already …

My memory was jogged by the reference to Chinese magic mirrors in Philip Ball's article on how the optical phenomena known as caustics can be used to create intricate images (2 February, p 40) . The Magic Casket , by R. Austin Freeman, includes a description of how the mirrors were made. Freeman wrote detective …

Jared Diamond states that "in our complex society, 2 per cent of the people can produce all the food" and that traditional tribes, in which every member has to help obtain food, would regard the rest of us as "freeloaders" and "parasites" (12 January, p 26) . Thankfully, in our complex society we have highly …

Your special report on sleep looked at dreams (2 February, p 31) . To what extent does describing dreams to a researcher modify your dreaming on subsequent nights?

Nigel Henbest's feature "Close call" looked at averting the threat to Earth from asteroid strikes (26 January, p 42) . I wonder if deploying a large number of balloons might work, in the manner of a bouncy castle.

I would like to suggest a few follow-up experiments that might shed more light on the "uncanny valley" – the feeling of unease when faced with a humanoid robot (12 January, p 35) . If part of the reason for the discomfort is that it is impossible to pin down the emotional state of such …

Fred Pearce wrote about the upcoming decision on the proposed Keystone XL pipeline to bring tar sands oil from Canada to the US (26 January, p 26) . One has to ask: why are we mining tar sands? We don't need to. The problem is that carbon burners pay nothing for their pollution. Yet if …

I am pleased that the National Institutes of Health is leading the way towards the phasing out of US medical research using chimpanzees (2 February, p 4) . However, I don't accept the suggestion in your report that the move will slow research on a hepatitis C vaccine. Our emphasis should be on existing research …

The commissioning of the Notrees battery facility in Texas to store surplus electricity from wind is interesting, but your story confuses energy and power (2 February, p 20) . It makes no sense to speak of storing megawatts of power: it is energy, denoted in joules or (mega)watt-hours, which is stored.

The recommendation by the royal commission in Victoria, Australia, for a "retreat and resettlement" strategy for homeowners in areas of "unacceptable" bushfire risk was a knee-jerk reaction (19 January, p 12) . Many factors behind increased vulnerability to bushfires remain to be properly addressed. These include reluctance to replace native fire-prone vegetation with more resistant …

Letter writer Brian Farrington is mistaken if he thinks free electricity will persuade people to accept a wind farm near their house (2 February, p 28) . I know of people unable to sell property at any price because of a nearby wind farm. So the idea of offering a few hundred pounds of free …