Letters archive

Laurence Steinberg presents some very interesting results on voting age and decision-making (11 October, p 30) . But they are fatally compromised because, far from "thinking outside the box", as the headline says, he has defined an arbitrary box called adolescence to dwell inside. Adolescence is a modern construct, less than 100 years old. A …

Steinberg says that because the "cold cognition" of adolescents is, by 16, likely to be as mature as that of adults, they should be allowed to vote. I would argue, though, that democracy has less to do with sampling the collective wisdom of the populace and more to do with ensuring the continued diversification of …

Considerations around setting appropriate voting ages need to include the role of voting in creating democratic societies, as well as young people's decision-making faculties. Voting may increase young people's stake in the system, stimulating their further involvement, as well as encouraging politicians to prioritise young people's views and needs in policy-making. Edinburgh, UK

I read Hal Hodson's article on e-citizenship (18 October, p 24) and your editorial (p 5) with a chill running down my spine. I am aware of the growing movement away from physical nations and geographical citizenship, but one of the most important functions of a nation state is to ensure that the poorest and …

How the marine protected area (MPA) in the British Indian Ocean Territory came about reads like the makings of a thriller, as described by Fred Pearce (27 September, p 26) . The significance and future value of protecting such vast areas of coral reef and associated marine habitat cannot be overstated. But the rights of …

The "pro-surveillance mantra" you mention – "if you have nothing to hide, you've got nothing to worry about" – is indeed stupid (11 October, p 5) . Governments can redefine what constitutes a crime, and may say this includes holding a certain opinion or belonging to a certain minority. Where I live, 70 years ago …

Laura Spinney writes about perception changes while wearing various types of inverting goggles (11 October, p 42) . I wonder how experiments in this area will change as high-definition virtual-reality headsets like the Oculus Rift become more widely available. For example, "perception" could be switched in an instant, without framing cues; or one eye could …

What the article did not mention is that our single-lens ocular system normally and always inverts the image on our retinas. If our sense of up and down depended only on the physical orientation of the retinal image, we would think we were walking on the ceiling. This surely is the most potent reason to …

The article calls to mind my daily experience. On first trying on spectacles with progressive lenses, which have a gradient of lens strength, it is difficult to make sense of the tumbling, tilting view of the world, with stairs appearing to move as you look down at them. For most, this soon settles down: the …

I approve of Michael Le Page's "Turbocharge our plants" plan to introduce improved photosynthesis genes not only into our food crops, but into wild plants as well (4 October, p 26) . Of course such manipulation will leave chaos in its wake, but that's a given. This is the Anthropocene age; we might as well …

There is one group of people who can do a lot to help stop Ebola (18 October, p 10) . They are the survivors. About 50 per cent of those who get the disease survive, and they are then, as far as is known, immune. They should be recruited to take care of those who …

For the last 45 years I have regularly read astrophysics articles, rarely understanding more than 10 per cent, but always fascinated. Now I read that in any game of quantum Russian roulette I would continue to breathe in one universe (27 September, p 32) . Surely this would apply to other potentially fatal situations – …

• Max Tegmark, who popularised quantum Russian roulette a couple of decades ago, says the thought experiment wouldn't confer immortality on any versions of you, because people don't die as the result of a quantum fluctuation. A gradual death does not, he says, prompt universes to fork. Sorry.

New Scientist has acclaimed the idea of pilotless planes (9 August, p 30) . Thoughtful attention to the issue of cosmic rays (4 October, p 12) should ground these proposals. What would be the fate of a pilotless plane that experienced data errors due to cosmic rays, as Quantas flight QF72 did in 2008 when …

Discussing waffle-like grids of matter in neutron stars (11 October, p 11) , Hal Hodson mentions that they occurred when a simulated star was "a million times hotter than the sun". Our star has a complex structure with many different temperatures. Do you mean the photosphere, the coronasphere or the core? Slough, Berkshire, UK

• The researchers report a temperature of 1.16 × 10 10 kelvin: two million times our sun's surface temperature of 5778 kelvin. For the purposes of the story, "a million times" conveyed "really very hot".

You report that the Sunflower solar collector "should be able to provide 12 kilowatts of electricity and 20 kilowatts of heat from 10 hours of sun" (4 October, p 19) . Is that 12 and 20 kilowatt-hours of energy in a 10-hour sunny day, or 12 and 20 kilowatts of power for 10 sunny hours, …

• The latter. The Sunflower will generate this power while the sun shines. In the regions of the world in which Airlight hopes to sell the device, it expects 10 hours of sufficient sunshine each day.

Your article on kids coding is the most exciting thing I have read in a long time (6 September, p 38) . At 79, I suggest that such initiatives would benefit the elderly too. I am currently a volunteer in a programme at the Glasgow University Memory Clinic looking at the effect of age on …

While my unschooled self secretly thinks that the many-worlds interpretation of quantum physics (27 September, p 32) is patently ridiculous, I'm happy that the piece of toast that my doppelgänger just dropped on the floor in another universe landed buttered side up. Seattle, Washington, US

• We should have located Alan Fridlund, who worked on finding research subject "Little Albert", at the University of California, Santa Barbara (4 October, p 10) . • In our account of topological insulators, on one occasion we called them topical insulators (11 October, p 38) . Doh.