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See newscientist.com for letters on: ● Deciduous delight ● Oil prudence ● Strange inheritance ● Nu-food redux ● Flash failure Spottings staus From Ch...

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See newscientist.com for letters on: ● Deciduous delight ● Oil prudence ● Strange inheritance ● Nu-food redux ● Flash failure

Spottings staus From Chris Heron Maxim Pospelov of the Perimeter Institute in Waterloo, Ontario, invokes negatively charged supersymmetric particles – “staus” – to explain anomalies in the abundances of primordial lithium isotopes (5 July, p 28). You also say that staus had their main effects 3 hours after the big bang, so the half-life of the stau must be of the order of hours, or at least minutes. If such a relatively long-lived and heavy particle existed, surely we would have found one produced in our atmosphere by the reactions of very energetic cosmic rays. Cambridge, UK

repetitive. Some parts – mainly the middle and ends of chromosomes – are so repetitive that it’s impossible to reassemble the jigsaw. Nanopore sequencing, in which a DNA sequence is read off as a strand passes through a pore, might overcome this problem but this technology is still at a very early stage.

Survival of the nastiest From Darcia Narvaez, University of Notre Dame I was surprised to read Mason Inman’s article reporting that “bad is good as a mating strategy” (21 June, p 12). The study seemed

Secret DNA From Rod Tranchant About a tenth of the human genome “remains impossible to sequence with existing methods”, Anna Gosline writes (5 July, p 36). I thought the whole thing had been sequenced; this is the first I’ve heard of this. Surely DNA is DNA, so if some can be done all can be done. What’s the problem? East Wittering, West Sussex, UK The editor writes: ● All existing methods work by breaking genomes into tiny pieces, sequencing those pieces and reassembling the resulting “jigsaw”. The trouble is that the human genome is highly

to be entirely based on self reports. Those who displayed narcissistic characteristics reported more sexual exploits. So? The conjunction between personality and reported exploits may be part of the personality complex. Schizophrenics report hearing more voices and religious fanatics report more sightings of devils and saints; but it doesn’t

mean their impressions are empirically verifiable. The data certainly doesn’t convince me. Notre Dame, Indiana, US

Miraculous moo From Dan Griscom You report a research finding that giving cows a genetically engineered hormone called recombinant bovine somatotropin (rBST) “cuts their emissions of the potent greenhouse gas methane by 7 per cent per litre of milk” (5 July, p 6). I understand that the average Holstein cow produces 21 litres of milk and 280 litres of methane each day. Such a cow, when given rBST, would appear to start absorbing methane at tea-time on the first day of milk production. After only a year it would be absorbing more than 150,000 litres of methane per day, though the barns would get windy. Fewer than 8 million such cows could absorb the total global production of methane from all sources. Melrose, Massachusetts, US The editor writes: ● Yes, it would have been more precise to say “by 7 per cent for a given daily milk production”. But it didn’t fit.

Nu-food redux From Chris Collins Your article about vat-grown meat (5 July, p 18) prompted a thought: “How about a milk machine?” Put

Enigma Brief N-counter No. 1505 Susan Denham

I DREW a grid of squares with N rows and N columns and I wrote the numbers 1, 2, …, N² in the squares in the natural order (left to right; 1 to N in the top row, N+1 to 2N in the next, and so on). I then cut up the grid into N pieces of www.newscientist.com

various shapes, with each piece consisting of N squares. On each piece the total of the N numbers is less than 200 and is not divisible by 2, 3 or 5. What is N? £15 will be awarded to the sender of the first correct answer opened on Wednesday 3 September. The Editor’s decision is final.

Please send entries to Enigma 1505, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to enigma@ newscientist.com (please include your postal address). The winner of Enigma 1499 is Simon Haines of Edinburgh, UK. Answer to 1499 Not quite right QUITE is 49270

grass and water in at one end and get milk – guaranteed free of tuberculosis – out of the other. The problems of making an acceptable product would appear, to an ignoramus like me, to be far less than those of animal-free meat production. Llandrindod Wells, Powys, UK

Diamond whisky From Paul Champion The Grimbledon Down cartoon by Bill Tidy that used to appear in New Scientist answered Rudolf Pfeiffer’s question over whether anyone has previously tried making diamonds out of drinks (21 June, p 29). In 1986 it was found that ethanol vapour would form a thin layer of diamond under certain conditions. Shortly thereafter Treem, director of the Grimbledon Down research complex, confronted a member of staff for requisitioning a bottle of the best malt from the social club (20 March 1986, p 65). Southall, Middlesex, UK

For the record ● Feedback said that Darren Wright, of the project to beam biscuit adverts to aliens, is an astronomer (5 July). He is a lecturer in radio and space plasma physics who lists his research interests as “Things”. ● We said that Australian companies “forecast spending $800 between 2002 and 2013 on geothermal exploration” (19 July, p 24). That should have been $800 million. ● The food business may well be “bad for the plant and your health”, but the subtitle of the book Eat Your Heart Out, by Felicity Lawrence (reviewed 5 July, p 47) refers to the planet. Letters should be sent to: Letters to the Editor, New Scientist, 84 Theobald’s Road, London WC1X 8NS Fax: +44 (0) 20 7611 1280 Email: [email protected] Include your full postal address and telephone number, and a reference (issue, page number, title) to articles. We reserve the right to edit letters. Reed Business Information reserves the right to use any submissions sent to the letters column of New Scientist magazine, in any other format.

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