Letters archive

Along with the downsides of climate variation for ancient civilisations (4 August, p 32) , could there have been some upsides? Bigger monuments and new gods for new odds could well be one, as could the demise of shamans too reliant on the previously predictable march of the seasons. Although not evident in the research …

Your look at those who use technology to closely monitor key aspects of their lives, such as health and activity (4 August, p 40) , was of interest to me, as my partner is an obsessive self-tracker. He reasons, quite rightly, that it enables him to identify patterns and thereby deal with problems such as …

In his recent look at the Schrödinger wave function, Marcus Chown states that "most physicists... believe the wave function to be merely a probability distribution" (28 July, p 28) , as if this purely mathematical entity were removed from any correspondence to physical reality. But the equations it underpins seem to work brilliantly, so it …

Copyright concerns over digital doppelgängers are one thing (11 August, p 38) , but who will people choose to sue when your electronic double issues something defamatory? You, or the company that enabled the creation of the avatar? Or will it be such a saintly avatar that it avoids this eventuality, and so will never …

Further to Feedback's look at Higgs boson humour (21 July) , in which you stated: "We preserve this joke for posterity, since as far as we know no national libraries have Twitter on the shelves." You might be interested to know that the US Library of Congress has digitally stored Twitter's archive material.

In the history of extreme parachuting (21 July, p 36) , Charles Bruce is worth a footnote. His book Freefall (Little, Brown, 1998) written under the pseudonym Tom Read, covers his abandoned attempt to be the first to free-fall more than 37 kilometres and to break the sound barrier unassisted. Sadly, he died in January …

Having just returned from a holiday where I had no cellphone or email access, and feeling very relaxed as a result, I read your article on a smartphone that feels your strain (11 August, p 20). If the constant access to work emails through my phone is stressing me out, maybe this app could let …

Your editorial on research that examines whether we have free will understates the paradox (11 August, p 3) . It is impossible to live as an automaton even if you believe that free will is an illusion. The last sentence: "We may not have the ability to choose, but we choose to think we do", …

Your discussion of the use of venoms as drug candidates ( 5 May, p 34 ) reminds me of the time I spent in the early 1950s detoxifying cobra venom for a project at the University of Miami that was having some success using it to treat polio. The development of the Salk vaccine for …

Having had aggressive prostate cancer picked up by yearly screening for prostate specific antigen (PSA), I can speak for the usefulness of this blood test (4 August, p 12) . My prostate was small and had no irregularities. At 59 years of age, I did occasionally have to get up in the night to urinate, …

We should not be surprised at the global jubilation and interest surrounding the touchdown of NASA's Mars rover, Curiosity, mentioned in your editorial (11 August, p 3) . Could anyone familiar with the incredible sequence of automated manoeuvres programmed into this craft to ensure a safe landing fail to be impressed? Our anthropomorphic treatment of …

Feedback's ongoing discussion of alternative systems of units (4 August) rekindled a memory from the 1950s. While working with physicists at Harwell in Oxfordshire, UK, we decided that both the metre-kilogram-second and centimetre-gram-second systems were rather sterile, lacking both culture and history. So we searched for something more suitable. The result was the furlong-pennyweight-fortnight system, …

You reported research showing an excess of left-handed amino acids in meteorites found in Canada (4 August, p 17) . Surely this could be used as evidence for panspermia, the theory that life on Earth was seeded from space, as proposed by astronomers Fred Hoyle and Chandra Wickramasinghe. If some process in space produces an …

Interesting as her analysis of the origins of inequality might be, do the comments by anthropologist Deborah Rogers (28 July, p 38) amount to anything more than an endorsement of 17th-century English political activist Gerrard Winstanley? He stated that: "The power of enclosing land and owning property was brought into creation by the sword."