Letters archive

I am not sure that advocates of free will can rest easy following the reinterpretation of Benjamin Libet's findings on readiness potentials (11 August, p 10) . What was previously seen as a preconscious process of planning and preparation is now just random noise building up until a threshold is hit. In each case a …

All types of screening give rise to false positives – and, tragically, false negatives as well. Prostate specific antigen (PSA) testing for prostate cancer is by no means fully reliable (4 August, p 12) . It remains, however, the only non-invasive test that detects four out of five prostate cancers. The condition is incurable once …

The possibility of launching small, cheap satellites into orbit may be exciting (25 August, p 42) . But what will happen to them once they reach the end of their life? Will we end up with hundreds of untracked steel boxes adding to the junk orbiting the planet?

You report two teams seeking to forecast economic meltdowns (11 August, p 6) . Neither seems to have dwelt on what would happen if their tool were to be acquired by people whose aim was to encourage financial meltdown, to profit from the fallout. If these two tools can, indeed, identify where the pivotal point …

I read the claim that a visual development tool means "anyone can be a coder" with disbelief (25 August, p 22) . A career in software development and sorting out failing projects has taught me that the last thing you need is the introduction of a random programming element. I prevent programmers writing any code …

I have read a lot about high intensity training (HIT), and recently watched the BBC Horizon programme The Truth about Exercise . So I was disappointed that your article on the health benefits of physical activity continued to push the old idea of long, boring workouts that do not really do any good, while ignoring …

Understanding IQ and how it relates to intellectual ability is an important line of research. Using it to determine who lives and dies in a state with capital punishment is a gross abuse (18 August, p 6) . The decision on the use of the death penalty is a societal decision. It has no scientific …

Sally Adee highlights the fact that current law is failing to address the ownership and licensing issues associated with digital personality (11 August, p 38) . The government of Guernsey is about to introduce legislation designed to accommodate exactly this. The Image Rights (Bailiwick of Guernsey) Ordinance, 2012 will, once established, permit registration of a …

Your article on the decline of bumblebee species and their importance to pollination (11 August, p 42) reports that the pesticide neonicotinoid is found in pollen and nectar, and is ingested by bees, scrambling their navigation system. Is it in the honey I eat daily? If so, what is it doing to my navigation system? …

Brian J. Ford may well have an explanation for so-called spontaneous human combustion, the fierce burning reported when bodies catch fire (18 August, p 30) . But what ignites the fire? I have read of a reported instance involving a well-to-do lady walking elegantly down a street. The only explanation for combustion was that she …

• Trevor Paglen's book The Last Pictures , which we reviewed (1 September, p 46) , is published by University of California Press and Creative Time Books.