- Email: [email protected]
Holy herd
For more letters visit www.NewScientist.com/topic/letters ■ Double-cross helix? ■ Truth or pare ■ Thou shalt not be popular ■ Day after day ■ Cosmic numerology ■ Science play time
elements inside nor those on the surface create each other. This concept still leaves the universe with graininess at a scale of around 10-16 metres – compared with the Planck length of 10-35 metres on the surface – but it does raise questions about the change in graininess as the universe has expanded, assuming the Planck length has always been the same. Wasaga Beach, Ontario, Canada
since paid particular attention to the hundred or so cattle and sheep visible from my kitchen window. Overwhelmingly, these animals align east-west. Frequently, this appears to be a response to strong winds, driving rain or fierce sun. Even in tranquil times, there is a clear east-west preference. It seems animals in Australia march to a different drum. Grazing kangaroos show no alignment preference at all. Foster, Victoria, Australia
28 units, sharply reducing the amount of time left to complete the primary task. For n people, this overhead is equivalent to (n × (n-1))/2 which is the number of unique pairs that can be chosen from the people communicating with each other. Try it. I would recommend reading Parkinson’s Law: Or the pursuit of progress. It’s must for scientists, engineers and managers. Stoke Gabriel, Devon, UK
Debit risk From Tim McCormack Mark Buchanan’s discussion of “unknown unknowns” (24 January, p 32) could usefully be applied to banks’ assumptions of credit risk exposure. Some use Monte Carlo simulations to calculate an acceptable level of value at risk. These use tables of probability of loans defaulting, provided by the rating agencies. One problem with this method is that the probability of any event occurring during the Monte Carlo simulation depends on the number of iterations of the simulation performed. In 1000 iterations there may be a 10 per cent chance of an “AAA”rated bond failure being included in the results. If by chance an AAA failure shows up in such a simulation run, it will produce a spike in the tail of the results graph and is likely to be dismissed as an improbable event. Why, then, include the possibility of an AAA default in the first place? Foyers, Invernessshire, UK
Magnetic cattle From Michael Kellock You reported on research, based on a large number of satellite photos, showing that cattle and some wild grazing animals align themselves predominantly along north-south lines, suggesting an awareness of the Earth’s magnetic field (30 August 2008, p 10). I have
Lead balloon
Talk isn’t cheap From Ted Lovesey Mark Buchanan refers to humourist C. Northcote Parkinson’s ideas about committees (10 January, p 38). Parkinson’s suggestions have more far-reaching applications than just committee size. When working on a project to reduce the crew workload in a large anti-submarine aircraft, I was continually being pressured to increase the crew size. In fact, such an increase would have added to the problem. This is because there is a “communications overhead” created by people interacting with each other. Say there were 1 unit of communication overhead for two people. With three people, the overhead for all three communicating together increases to 3 units – one for each two-way conversation available. By the time eight crew members are communicating, the overload has risen exponentially to
From James Sandemans I enjoyed Paul Collins’s article on metal balloons down the ages (10 January, p 44). I am not sure, however, about his remark that, since 1941, “no more metal-clads have taken to the skies”. I seem to recall reading, 30 or 40 years ago, of a successful project at the Massachusetts Institute of Technology to design, build and fly a balloon constructed entirely of lead. Glasgow, UK The editor writes: ■ MIT’s neighbours at the consultancy Arthur D. Little flew both a lead balloon and a dirigible in May 1977: see photos at www. leadballoon.notlong.com. The US TV programme Mythbusters also managed to loft a balloon made of lead foil in January 2008.
Holy herd From Zoe Hudson David Robson discussed the herd mentality in humans (7 February, p 13). On the rare occasions that I have been to church, I witnessed the power of singing as part of a congregation and the connection you feel with those standing next to you. I found myself caught up in the moment with emotions of unity, purpose, elatedness and (unusually for me) spirituality.
From such experiences I can appreciate how contagious the belief in a god could be, especially when one is feeling particularly lost in life. Reinforcing faith through mass worship is evident in religious holidays, pilgrimages and ritualistic behaviour. I believe the herd mentality is fundamental to the persistence of organised religion. Oxford, UK
For the record ■ We wrongly stated that the World Health Organization recommended in September 2008 that the electronic cigarette be banned (14 February, p 33). The WHO in fact stated that it did not consider the electronic cigarette to be a legitimate therapy for smokers trying to quit. ■ We said that in 1709 “from Czechoslovakia in the east… everything turned to ice” (7 February, p 46). No such country existed in 1709. It was founded in 1918 and split into the Czech Republic and Slovakia in 1993. ■ Our picture of the starfish Luidia sarsi was upside down (24 January, p 36).
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.
28 February 2009 | NewScientist | 25
elements inside nor those on the surface create each other. This concept still leaves the universe with graininess at a scale of around 10-16 metres – compared with the Planck length of 10-35 metres on the surface – but it does raise questions about the change in graininess as the universe has expanded, assuming the Planck length has always been the same. Wasaga Beach, Ontario, Canada
since paid particular attention to the hundred or so cattle and sheep visible from my kitchen window. Overwhelmingly, these animals align east-west. Frequently, this appears to be a response to strong winds, driving rain or fierce sun. Even in tranquil times, there is a clear east-west preference. It seems animals in Australia march to a different drum. Grazing kangaroos show no alignment preference at all. Foster, Victoria, Australia
28 units, sharply reducing the amount of time left to complete the primary task. For n people, this overhead is equivalent to (n × (n-1))/2 which is the number of unique pairs that can be chosen from the people communicating with each other. Try it. I would recommend reading Parkinson’s Law: Or the pursuit of progress. It’s must for scientists, engineers and managers. Stoke Gabriel, Devon, UK
Debit risk From Tim McCormack Mark Buchanan’s discussion of “unknown unknowns” (24 January, p 32) could usefully be applied to banks’ assumptions of credit risk exposure. Some use Monte Carlo simulations to calculate an acceptable level of value at risk. These use tables of probability of loans defaulting, provided by the rating agencies. One problem with this method is that the probability of any event occurring during the Monte Carlo simulation depends on the number of iterations of the simulation performed. In 1000 iterations there may be a 10 per cent chance of an “AAA”rated bond failure being included in the results. If by chance an AAA failure shows up in such a simulation run, it will produce a spike in the tail of the results graph and is likely to be dismissed as an improbable event. Why, then, include the possibility of an AAA default in the first place? Foyers, Invernessshire, UK
Magnetic cattle From Michael Kellock You reported on research, based on a large number of satellite photos, showing that cattle and some wild grazing animals align themselves predominantly along north-south lines, suggesting an awareness of the Earth’s magnetic field (30 August 2008, p 10). I have
Lead balloon
Talk isn’t cheap From Ted Lovesey Mark Buchanan refers to humourist C. Northcote Parkinson’s ideas about committees (10 January, p 38). Parkinson’s suggestions have more far-reaching applications than just committee size. When working on a project to reduce the crew workload in a large anti-submarine aircraft, I was continually being pressured to increase the crew size. In fact, such an increase would have added to the problem. This is because there is a “communications overhead” created by people interacting with each other. Say there were 1 unit of communication overhead for two people. With three people, the overhead for all three communicating together increases to 3 units – one for each two-way conversation available. By the time eight crew members are communicating, the overload has risen exponentially to
From James Sandemans I enjoyed Paul Collins’s article on metal balloons down the ages (10 January, p 44). I am not sure, however, about his remark that, since 1941, “no more metal-clads have taken to the skies”. I seem to recall reading, 30 or 40 years ago, of a successful project at the Massachusetts Institute of Technology to design, build and fly a balloon constructed entirely of lead. Glasgow, UK The editor writes: ■ MIT’s neighbours at the consultancy Arthur D. Little flew both a lead balloon and a dirigible in May 1977: see photos at www. leadballoon.notlong.com. The US TV programme Mythbusters also managed to loft a balloon made of lead foil in January 2008.
Holy herd From Zoe Hudson David Robson discussed the herd mentality in humans (7 February, p 13). On the rare occasions that I have been to church, I witnessed the power of singing as part of a congregation and the connection you feel with those standing next to you. I found myself caught up in the moment with emotions of unity, purpose, elatedness and (unusually for me) spirituality.
From such experiences I can appreciate how contagious the belief in a god could be, especially when one is feeling particularly lost in life. Reinforcing faith through mass worship is evident in religious holidays, pilgrimages and ritualistic behaviour. I believe the herd mentality is fundamental to the persistence of organised religion. Oxford, UK
For the record ■ We wrongly stated that the World Health Organization recommended in September 2008 that the electronic cigarette be banned (14 February, p 33). The WHO in fact stated that it did not consider the electronic cigarette to be a legitimate therapy for smokers trying to quit. ■ We said that in 1709 “from Czechoslovakia in the east… everything turned to ice” (7 February, p 46). No such country existed in 1709. It was founded in 1918 and split into the Czech Republic and Slovakia in 1993. ■ Our picture of the starfish Luidia sarsi was upside down (24 January, p 36).
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.
28 February 2009 | NewScientist | 25