Letters archive

Where does everyone get the idea that the universe is fine-tuned for life (for example: 6 December 2008, p 12) ? If it were that finely tuned, it would be teeming with life. But it's not. As far as we know, the only place in the universe with any life able to cling to it …

Anil Ananthaswamy passes on the assumption that all parts of the universe must once have been in causal contact in order for the temperature of the universe to be as uniform as we find it today (13 December 2008, p 32) . Surely it is possible that the temperature of the universe is uniform because …

An Exxon-funded study has once again given the enormous Exxon Valdez crude oil spill site "a clean bill of health" (20/27 December 2008, p 6) . We need to remember that Exxon fouled not only the uniquely productive waters in Alaska's Prince William Sound, but also more than 1000 miles of shoreline, out to Cook …

Mikhail Shchepinov advocates heavy water and other isotope-labelled molecules to combat ageing (29 November 2008, p 36) . You caution that the idea of using heavy isotopes to increase longevity hinges on free radicals being at the root of ageing. While that might be strongly debated, there are a number of diseases in which reactive …

In speculating about the mechanism which causes homosexuality, you write that "perhaps our brains get too much or too little of a crucial hormone in the womb," (20/27 December 2008, p 33) . That implies that just the right amount of hormone is the amount that produces heterosexuality. This normative claim is not supported by …

Richard Hammond ponders why kids get turned off science so successfully these days (3 January, p 14) . The answer is that kids are interested in the world they see and feel around them – while science has largely abandoned this world for the unseen world. What evidence do I see around me of relativity, …

Joerg Heber notes that the price for abandoning silicon-based technology is "huge" (6 December 2008, p 35) . That is the core reason why silicon will not be abandoned. It has cost trillions of dollars to bring silicon to its dominant position. A new silicon fabrication plant costs up to $5 billion. A universal conversion …

I worked out the areas of the wrapping of the two-dimensional parcels containing up to seven thin mince pies, in both sausage and cluster formats (20/27 December 2008, p 67) . In your article Ian Stewart states that the sausage arrangement should have the lowest area, but by my calculations, in every case, the cluster …

Peter White suspects our universe is a cosmic engineering undergraduate's final-year project (10 January, p 16) . I thought I had explained that it's the mice... the hyper-intelligent pan-dimensional mice... He might be willing to award it more than a second-class degree if he lived somewhere other than Wales. Somewhere with more fjords, perhaps?

• We said "in the UK... the National Institute for Clinical Excellence is charged with undertaking cost-benefit analyses of treatments for the NHS" (10 January, p 29) . NICE has no role in Scotland.

Mathematician Ian Stewart's thoughts on wrapping mince pies in string (20/27 December 2008, p 67) looked like a simple way to encourage an interest in maths in my 9-year-old son. We put string around 6 AA batteries – even more plentiful than mince pies at our Christmas – and found that 20 centimetres of string …

Michael Brooks (20/27 December 2008, p 16) and Richard Hammond (3 January, p 14) each ask a question that has occupied the scientific community in the UK for a long time: how can we effectively popularise science and reduce the reported decline of interest in science subjects at school? We must not, however, forget science …

The analysis of the optimum number of members of a committee (10 January, p 38) reminded me of a simple relationship that I speculated on for expressing the potential value of meetings in organisations. My initial thoughts were that the effectiveness of a meeting is inversely proportional to the number of people attending the meeting. …

Responding to Lawrence Krauss's proposal that physics has largely answered the question "why is there something rather than nothing?" (22 November 2008, p 53) , John Turner (10 January, p 16) suggests that Krauss thereby strays into metaphysics by substituting "how" for "why". I suggest the opposite is the case. The word "why" contains the …

Terence Kealey's arguments about the economic laws of research and the pros and cons of funding it privately or publicly would be easier to follow if he clearly distinguished science from technology (3 January, p 42) . Obviously scientists, finding out how the natural world works, use much technology in their work and sometimes invent …

If a supernatural theory is an "unfounded leap of logic" (6 December 2008, p 48) , so is an assumption that science is the only true path to truth. Values, conscience, purpose, history, art, the justification for the scientific method itself – all are beyond the scope of the scientific method. Science opens up a …