Letters archive

Simon Thompson's claim that yawning is associated with brain warming seems to be pure speculation (20/27 December 2014, p 38) . When offered a hot towel during flying, I always applied it to my forehead, but it never made me start to yawn. Applying moderate heat or cold to the head is unlikely to alter …

Simon Thompson suggests that people with autism aren't as prone to contagious yawning as other people are because they can't recognise facial expressions. Yawning is not the sort of subtle facial expression that some autistic people may find hard to read. As Thompson writes, studies have shown that contagious yawning is related to how close …

As a trial lawyer of more than 20 years' experience, I was interested to read about linguist Alan Yu's research regarding the effect of a lawyer's voice on court judgments (3 January, p 12) . However, it seems that Yu has missed one very important factor: the relative merit of each case. We lawyers do, …

I was pleasantly surprised by Michael Brooks's article on quantum gravity (3 January, p 26) , and like all good articles it got me thinking. If photons, particles, atoms and so forth can exist in superpositions, interact with themselves and create two gravitational fields, would it not be possible to detect the extra mass? And …

It's a great question, and one we don't know the answer to yet.

Michael Slezak writes that plants grown in space will need the soils we bring with us (20/27 December 2014, p 6) . But why? In the Mars mission study programme in the early 1980s, NASA established that soil-less aeroponics was the best way to grow crops in space – mainly because it made large weight …

The Theory of Everything is a well-acted biography of Stephen Hawking, which portrays scientists in a more realistic light than most films manage to do (3 January, p 40) . However, it severely minimises and distorts the role of Dennis Sciama, Hawking's doctoral supervisor. Sciama is portrayed as a cartoon character, a kind of authoritarian …

Curtis Abraham's article on the importance of science to developing countries could also have mentioned the importance of English as the lingua franca of science (3 January, p 22) . In Thailand, where I live, very few academics and almost no students can read English, and this isolates them from developments in science outside their …

I enjoyed Brian Wansink's article describing how environmental tweaks can influence what is eaten, and in what amounts (10 January, p 36) . So I was disappointed that he did not cite the work of Stanley Schachter and his colleagues, who reached similar conclusions in their 1960s research. Schachter remains a hero of mine because …

Should I go rock climbing on the 6 kilometre peak of Saturn's moon Mimas (20/27 December 2014, p 58) , I think I'll avoid the temptation to "simply leap off the top and float down to the surface", as Rebecca Boyle suggests. Even though Mimas has only about half a per cent of Earth's gravity, …

I have a game I like to play with those who believe in conspiracy theories (20/27 December 2014, p 36) . The basic idea is that believers in one conspiracy tend to believe in others as well. You can point out the contradictions simply by running two conspiracies together, and asking them how they make …

In considering the possible health hazards of radioactive isotopes, it may be critically important to take into account the chemistry of the molecule in which the isotope is incorporated. John Evans (3 January, p 55) reminds us that tritium is as explosive as hydrogen, and Harvey Rutt (20/27 December 2014, p 43) may have been …

From Keith Bremner , Tecumseh Fitch states that the brains of domesticated animals become smaller than those of their wild cousins (3 January, p 24) . In your Christmas quiz, you wrote that "Humans 10,000 years ago had brains that were 15 per cent larger than ours" (20/27 December 2014, p 89) . Does this …

We may have. Anthropologists convened last year to discuss the idea that many features of modern humans can be attributed to a process of self-domestication, see: bit.ly/self-domestic .

Christopher Kemp's article on Maxim Makukov and Vladmir sh Cherbak's theories suggested that there are patterns in DNA's genetic code that could not have arisen randomly and so must have been planted there by alien life designers (20/27 December 2014, p 61) . But DNA didn't just arise by random processes. Although we don't know …

I have, on occasion, accused friends, family and colleagues of having "selective hearing", but never to the degree attributed to Neanderthals in your Christmas quiz (20/27 December 2014, p 89) . You write that "there's no evidence they could hear sounds that no known animal can make." How sad that they never heard the roar …

We've docked 10 points from ourselves; we should have said "the ability to hear sounds of a pitch higher than any known animal can make", which is a quality of the greater wax moth, but not Neanderthals.

• We had our wires crossed in the article on self-heating fabrics (3 January, p 15) . It is a current – not a voltage – that is run through the cloth.