Letters archive

I was initially intrigued and then disappointed by Mark Buchanan's article "Quantum minds" (3 September, p 34) . The observation that our decision-making processes resemble quantum mathematics is interesting. However, Buchanan pulls back from even the vaguest suggestion that the brain might be a quantum-mechanical machine. Researchers have been studying quantum biology for years. It …

Your article on an upcoming field test for engineering the climate with atmospheric aerosols (10 September, p 8) and the editorial defending such trials (p 3) give ammunition to critics of such work. These trials might make the public more complacent about climate change and less willing to be inconvenienced to deal with it. What's …

Your feature on the harmful consequences of concussion suggests an unexplained cellular "domino effect" is involved (10 September, p 38) . The process starts when a damaged cell leaks something that causes a neighbouring cell to die and leak more of that something, and so on. There is much evidence that the something is unliganded …

As Allison Macfarlane articulates, nations that have nuclear power must also have an operational plan for long-term storage and disposal of high and intermediate-level waste (27 August, p 26) . At last the UK is addressing this. Since 2008 the policy has been to develop a geological disposal facility (GDF), and volunteer communities are being …

Your valuable editorial "Credible or inedible" (3 September, p 5) needs some clarification: PETA is not backing the laboratory production of in vitro meat to allow vegetarians to "tuck in with a clear conscience", but to provide a source of ethically obtained meat for meat-eaters. They, like smokers trying to quit tobacco, find it very …

I was taken aback by the suggestion that the discovery of a gene linked to tooth enamel production could lead to the reactivation of enamel-producing cells to avoid decay (28 May, p 17) . When a tooth is developing, ameloblast cells are responsible for enamel formation, but they die once this process is complete, before …

Contrary to Sebastian Hayes's letter (10 September, p 32) , from its second edition onwards Richard Dawkins's The Selfish Gene has a chapter about altruism as an important part of evolution. Dawkins takes the position that genes are "selfish" in the sense that their only concern is replication, not that they make their carriers selfish. …

In "Racial grant gap" (27 August, p 5) , you report that "black scientists receive 10 per cent fewer funding awards than would be expected if race were not an issue". While true, the numbers also show white scientists receive awards nearly twice as often as black scientists – a more damning figure. Percentages can …

I was intrigued to learn that the body temperature of king penguin chicks falls when they are fed cold meals (20 August, p 16) . How often do they get hot ones?

Celeste Biever can take heart after not completing the ultimate intelligence test (10 September, p 42) . Knowing when to give up on a frustrating task is in itself a fair test of intelligence.

Astrophysicist Jason Steffen's optimal method for boarding an aircraft in alternate rows (10 September, p 14) is a great idea and should be implemented by all airlines immediately. The disembarking bottleneck could be avoided by allowing able-bodied passengers to use the emergency exits and slides. This would have the added benefit of testing the slides …

• In the story on oil supplies (27 August, p 4) , Libya's 2009 output should have been 2.4 million barrels a day • Researcher José Hernández-Orallo, quoted in the feature on a universal intelligence test (10 September, p 42) , is from Technical University of Valencia, Spain