observations, including SETI, are confined to tiny parts of the radio spectrum. These astronomical bands were chosen largely because they are rich in natural sources; moreover it would be daft to choose for communication those channels that maximise noise – and these are the same throughout the universe.

Rational aliens would minimise power demands and maximise bandwidth by communicating using the highest easily generated and detected frequencies compatible with low noise and signal loss in the interstellar medium – that is, at frequencies away from natural sources, precisely those on which we are not listening for them.

And they wouldn’t expensively broadcast to the universe at large the implicit message “here I am, come and get me”.Northbridge, New South Wales, Australia

From Malcolm OliverIt really has to be time for SETI to change its name to ensure success. The present name suggests Set, the ancient Egyptian god of disorder and chaos. I suggest Mapping Astral Alien Territories, which would give us MAAT – the goddess of order, justice and truth.Old Bar, New South Wales, Australia

Steam-boosted carsFrom Rob MannionMichael Brooks’s report on more efficient cars was interesting

( 2 February, p 32 ). But another idea for reducing fuel costs on petroleum-powered vehicles – water injection – seems to have died a death.

Over 35 years ago I noticed that one of my Morris Minor cars, which was getting water in the cylinders through a leaking head gasket, ran beautifully once started, producing noticeably more power and using less fuel.

I fitted a metered water spray into the inlet manifold of another beloved “Moggy”. It achieved 4.7 litres per 100 kilometres (60 miles to a measured imperial gallon), while an identical non-equipped vehicle rarely achieved 6 litres per 100 kilometres.

The best results were achieved after several miles, when the cylinder block reached a good working temperature. Turning off the water spray two miles before the end of the journey reduced problems with emulsification of lubricating oil and fuel. I had as many things to remember as a steam locomotive driver – but otherwise it was most successful. Why has it disappeared? Bournemouth, Dorset, UK

Yo! Yo’ ‘yo’…From Stephan GyoryMark Peters states that linguists have been looking for a gender-neutral personal pronoun for 200 years ( 5 January, p 7 ) and quotes Elaine Stotko suggesting that while none of the top-down suggestions have taken, “yo” might be emerging naturally. One of the examples given is “Yo put his foot up”. Is this a mistake, because the word “his” appears in the sentence? A much more common gender-neutral term is “they” – so common that Microsoft Word recognises it.Sydney, Australia

Mark Peters writes:● The “foot” sentence might not have been a great example in retrospect… Stephan Gyory is correct that “they” is the real solution to all of this, but many

people vehemently hate this use because they want the word to stay plural. I cut a mention of it from the first draft of my article.

An errata From Jon ArchI have always been impressed by the standard of grammar and punctuation in New Scientist, but my heart sank when I read “Name that bacteria in one” ( 16 February, p 28 ). The singular of bacteria is bacterium. I can cope with “this data” since we rarely use “datum” (unless we’re surveyors) and data has a spreadable feel, like butter.

But why use “bacteria” as both singular and plural? It helps understanding to distinguish singular and plural. Will we have “bacterias” one day?

And while I am having my little rant, I find it amusing that I referee papers in which cells are bathed in “media”, though the only medium used is “Dulbecco’s Modified Eagle’s Medium”.

Can we please preserve the mitochondrion as well? I look to you to help control my blood pressure and give me a long life.Buckingham, UK

Smoking gunFrom Jean Marston From 1955, I was a doctoral student and later a researcher working under the guidance of professor Ronald Fisher, whose scepticism over the link between smoking and cancer Ray Johnstone mentions ( 2 February,

p 19 ). I used mice to study the inheritance of susceptibility to lung tumours induced by chemicals in tobacco smoke and Fisher encouraged me throughout.

Fisher was interested in Richard Doll and Austin Bradford Hill’s papers on the subject and was keen to question them. He prepared a very elegant proof, using the same methods as Doll and Hill, to show that there was a direct correlation between the import of apples and the increased divorce rate. However, this work was funded by the British Tobacco Research Council, which meant that Fisher was considered to be biased and his work suspect.Penrith, Cumbria, UK

For the record

● Discussing whether animals think like autistic savants ( 23 February, p 8 ) we said that using the right hemisphere allowed birds to process only categorical features of a scene, and using the left meant they could attend only to the details of a stimulus. In fact the right hemisphere processes details and the left processes categorical features.● The reference to the paper by Josh McDermott and Marc Hauser on monkeys’ musical motivation ( 23 February, p 29 ) should have been Cognition, vol 104, p 654 .● The reference to the paper “Discovery of a Jupiter/Saturn analog with gravitational microlensing” by Scott Gaudi and colleagues ( 23 February, p 17 ) should have been Science, vol 319, p 927 .● We described Leonore Tiefer, at the New York University School of Medicine, as a psychiatrist ( 23 February, p 6 ); she is a psychologist.

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