Letters archive

According to Michael Brooks, we don't know what gravity is ( 13 June, p 28 ). However, in 1992 I proposed a theory to explain its origin ( Europhysics Letters , vol 17, p 1 ). Gravity is the result of the quantum interaction of matter with the surrounding vacuum, which in turn interacts with …

I found Richard Wiseman's Twitter experiment to determine whether remote viewing – the psychic ability to "see" distant locations – was real (13 June, p 23) and its attendant findings (13 June, p 6) very interesting. "Blind guesswork" screamed the header showing pie charts of the findings. Yet the roughly chance findings are pretty much …

It amuses me that in Mark Buchanan's article "Can science fix economics?" it is suggested that "it should be possible within a decade to have functioning models of the global economy to which policy-makers could look for sound insights" ( 6 June, p 35 ). For those of us with long memories, this is just …

Your article "Trains recast as climate baddies" discusses the relative emissions of different modes of transport (13 June, p 7) . I note with interest that, per kilometre, train travel has a similar carbon dioxide output per passenger to air travel, when manufacture, infrastructure and maintenance are considered. However, while the study is presented as …

You state in your article "Trial inequality" that women are under-represented in clinical trials of cancer drugs, yet do not give any explanation as to why (13 June, p 7) . Rather than being due to sexism, this under-representation arises because it is imperative that women don't become pregnant when testing new drugs and risk …

Perry Bebbington's idea of an antimatter universe, receding in time from the big bang (6 June, p 27) goes back at least to J. Richard Gott's 1974 paper in The Astrophysical Journal ( vol 187, p 1 ). More recently, John Gribbin ascribed the idea to Victor Stenger while reviewing his book The Comprehensible Cosmos …

In his report on animal species that appear to have numeracy skills (20 June, p 37) , Ewen Calloway says: "The ability to count may date back to even more primitive organisms than fish," citing bees as an example. Bees more primitive than fish? Not at all. Bees evolved more recently than fish by about …

Not only patients whose fingerprints have been degraded by the cancer drug capecitabine are embarrassed by US immigration procedures (30 May, p 5) . Playing jazz bass degrades one's fingerprints to the point of unreadability, in my experience. Despite Anil Jain's assertion in the same article, the nuisance of border delays is not "the price …

• Our article on the role of science in the verification of nuclear weapons failed to make it clear that North Korea left the 1968 Nuclear Non-Proliferation Treaty in 2006 and tested a bomb at that time, as well as in May this year (27 June, p 8) . • Far from suggesting that mathematics …