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It is rocket science
OPINION LETTERS Big answers From Hugh Watson This year, at the age of 50 and having led a healthy life, I was diagnosed with signet ring cell cancer of the colon, which has spread. I have one to two years to live. Having been a New Scientist reader for 28 years, I turned to it for wisdom – and found it. When I die I will in all likelihood not go to heaven. The evidence is against God’s existence (17 March, p 46). Those of faith might say absence of evidence is not evidence of absence. For me, Occam’s razor prevails. Do I fear the reaper (20 October, p 42)? No, but I would like to live to see my three young children grow up. What about new therapies (13 October, p 38)? No one seems to be doing anything related to this cancer. I guess this one is at the back of the funding queue. So what hope? Well, I now cycle for over 75 minutes a week as recommended by the American College of Sports Medicine (25 August, p 38) and I have started fasting for two days a week as recommended by the Longevity Institute (17 November, p 46). Will this lengthen my life? Time will tell. I am not on chemotherapy at the moment, but I hope that as well as
The science can still be done; the voters just don’t want to pay for it. Secondly, I think that for much of human history, caution and group loyalty have been useful survival traits. If history really does repeat itself, those times may come again. Houston, Texas, US
poisoning rapidly dividing cells, the fact that chemo stops most people eating has a hidden benefit that fasting might provide. Maybe life is just an interesting simulation (29 September, p 47). Nevertheless, I want it to continue. Is there anyone out there with a cure for signet ring cell cancer of the colon? Cumbernauld, Glasgow, UK
Divisive biology From Rapier Dawson I agree with much of the article on political biology by Jesse Graham and Sarah Estes (3 November, p 40) but I take issue with them in two areas. First, it is quite proper in a democracy for the government to avoid funding science that voters do not like.
Enigma Number 1729
Xmas gifts SUSAN DENHAM I have given each letter of the alphabet a different whole-number value from 1 to 26. Therefore I can now work out the value of any word by adding up the values of its letters. For example, XMAS and GIFTS both make 34. It turns out that all the following words have the same value as each other: WE THREE KINGS OF ORIENT ARE. What are the values of A, N, S, W, E and R? WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 23 January. The Editor’s decision is final. Please send entries to Enigma 1729, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to [email protected] (please include your postal address). Answer to 1723 Four lots of dots: I drew 49 dots The winner Les Slow of Pocklington, East Yorkshire, UK
40 | NewScientist | 22/29 December 2012
From Dennis Altman, Institute for Human Security, La Trobe University As someone who in US terms would be a deep liberal, I was shocked to read Graham and Estes’ statement that: “As a rule, conservatives are more likely than liberals to prefer white people, straight people and high-status groups. Liberals are more comfortable… with members of ethnic and sexual minorities.” The implication is that all nonwhite, non-straight people are somehow outside the general population, which can be neatly divided into liberals and conservatives . Melbourne, Victoria, Australia
Pump it up From Chris Vivian, National Marine Adviser, Centre for Environment, Fisheries & Aquaculture Science In his letter on ocean thermal energy conversion (OTEC), Graham Cox suggests it could be used to fertilise surface waters with nutrient-rich deep water to promote plankton growth for carbon capture (1 December, p 31). However, there is a problem. Deep water often contains a lot of dissolved inorganic carbon from sinking organic matter which would be released by the process, and so would greatly reduce, if not eliminate, any benefits. This was indicated in research by Andrew Yool et al (Journal of Geophysical Research, vol 114, p C08009) and Andreas Oschlies et al (Geophysical Research Letters, vol 37, p L04701). Lowestoft, Suffolk, UK
Not so fruitful From Ed Manning In regard to your story on the impact of grapefruit on drugs (1 December, p 17), I was aware of its effect in connection with statins, but not more broadly. Given that it interferes with an enzyme that breaks down several drugs, would it not be desirable to combine grapefruit or its active component with some of these drugs in order to reduce the required dosages? New York, US The editor writes: n According to the researchers involved, this is not likely to improve drug therapeutics, and would likely complicate the clinical use of these medicines.
It is rocket science From Clive K. Semmens Elon Musk says that “with a nuclear thermal rocket, you could definitely reach a tenth of the speed of light” (1 December, p 27). Nonsense. The speed of light is 300,000 kilometres per second. The most heat-resistant material known (for the combustion chamber of such an engine) has a melting temperature of about 4300 kelvin. The mean velocity of hydrogen ions at about 4300 K is about 10 km/s – so that’s the highest possible exhaust velocity for a thermal rocket, whatever its energy source. This implies that the initial mass of a thermal rocket must be at least 2(v/10) where v is the final velocity in km/s. This is an inescapable lower bound, and in practice it would be much higher. To reach one-tenth of the speed of light (30,000 km/s), the initial mass of a thermal rocket is therefore at least 23000 times its final mass, or 10900 if you prefer. You could do a lot better, in theory, with a rocket with an ion drive, with its much higher
To join the debate, visit newscientist.com/letters
exhaust velocity – but one-tenth of the speed of light would still be cloud cuckoo land. Ely, Cambridgeshire, UK
The buyer pays From Peter Ryan If we wish to use the tax system to reduce greenhouse gas emissions, we need to avoid targeting industry, as happens in California and elsewhere (24 November, p 14). Instead, we should tax consumers based on the carbon footprint of the goods or services they are buying. This would reduce the opportunity for companies to avoid a carbon tax by moving their production facilities overseas. A carbon-added tax could work in a similar way to VAT, based on the final carbon footprint of goods or services. Ayr, UK
Money for Mars From Vincenzo Liguori Just in case there remain any doubts about NASA’s bias towards the Red Planet at the expense of everything else, another Mars rover is announced at a cost of $1.5 billion (15 December, p 8). This is after $2.5 billion for Curiosity, $500 million for the yet-to-be-
launched Mars Atmosphere and Volatile Evolution (MAVEN) mission and $425 million for the yet-to-be-launched Interior Exploration using Seismic
Investigations, Geodesy and Heat Transport probe (InSight). So, around $5 billion for Mars alone at a time when $2 billion for an orbiter for Neptune, or Jupiter’s moon Europa, or Saturn’s moon Titan could not be found. Even when someone came up with a mission to Titan’s lakes for $425 million, NASA chose InSight. Even though Mars seems ever less likely to be capable of sustaining life, I am not against its exploration. I like it. I would just like a more equitable distribution of scarce funds. I am also surprised that interested groups such as the Planetary Society don’t seem to have reacted; not a peep out of them as NASA announces more and more money on Mars while cutting the rest. Dee Why, New South Wales, Australia
Electric universe From Greg Shanahan When physicist Timothy Horbury says “everything we’ve seen [from the Voyager probe] is not what we expected to see”, he appears to be referring to standard cosmological models and their predictions for what the transit from our solar system to interstellar space should be like (newscientist.com, 4 December). Those influential in the nonstandard plasma cosmology field, such as physicists Anthony Peratt and Donald Scott, would be more surprised if the electromagnetism that Voyager has detected, and which has been described as a “magnetic highway”, was missing. If the measured electromagnetic fields are factored into the forces that govern galaxies, perhaps we can end the fruitless 20-year search for dark matter to explain how galaxies are held together, and let gravity take a back seat to electromagnetic effects. Rosebank, New South Wales, Australia
All aboard From Phil Bly The Japanese passenger train that is based on a roller-coaster is interesting. Since no motor is needed, it can be light and efficient, though it was noted that motorised vehicles can use
animal husbandry, and we started to “modify” food by selective breeding. Then we discovered how to alter genes in the lab. This suggests three label codes would suffice. GN (Genes Natural), SG (Selected Genes) and GM (Modified Genes). I believe that the proof of the pudding is in the eating, and I wish the GN-only fanatics the very best of luck. Donvale, Victoria, Australia.
Going forward
regenerative braking and may be just as energy efficient (8 December, p 22). However, it still operates as mass transport to many different destinations, so it must keep stopping, which wastes energy and time. There are ways of avoiding this, as exemplified by the Personal Rapid Transit system at Heathrow Airport in London. It uses small, automatic energyefficient driverless vehicles to carry people non-stop from origin to destination. It is strange that designers are still fixated on the traditional model of public transport, when automation can provide not only a higher level of personal service, but also greater energy efficiency. Monmouth, UK
Good taste gene From Derek Williams Even though Californians voted against mandatory labelling of genetically modified foods (17 November, p 28), it is worth considering the details of a suitable system. For a long time everything humans ate was “natural” food. Then came agriculture and
From Robert Dooman Roger Penrose and Stephen Hawking concluded that the big bang must truly be the beginning. As you discussed, we are left to figure out how the big bang occurred ex nihilo, without prior substance (1 December, p 34). The ancients wisely advised us to leave this line of inquiry to the Muses. Maybe we’d be better served investing our time in finding new vaccines instead of searching for where the beginning began. Chicago, Illinois, US
Time for change From Paddy Shannon In your editorial on North Korea you said that “the regime may be atrocious, but what its people need above all else is humanitarian aid” (24 November, p 5). At the risk of jeopardising my future invitation to Pyongyang to lecture on plain speaking, what they need above all else is drastic regime change. Lancaster, UK
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.
22/29 December 2012 | NewScientist | 41
The science can still be done; the voters just don’t want to pay for it. Secondly, I think that for much of human history, caution and group loyalty have been useful survival traits. If history really does repeat itself, those times may come again. Houston, Texas, US
poisoning rapidly dividing cells, the fact that chemo stops most people eating has a hidden benefit that fasting might provide. Maybe life is just an interesting simulation (29 September, p 47). Nevertheless, I want it to continue. Is there anyone out there with a cure for signet ring cell cancer of the colon? Cumbernauld, Glasgow, UK
Divisive biology From Rapier Dawson I agree with much of the article on political biology by Jesse Graham and Sarah Estes (3 November, p 40) but I take issue with them in two areas. First, it is quite proper in a democracy for the government to avoid funding science that voters do not like.
Enigma Number 1729
Xmas gifts SUSAN DENHAM I have given each letter of the alphabet a different whole-number value from 1 to 26. Therefore I can now work out the value of any word by adding up the values of its letters. For example, XMAS and GIFTS both make 34. It turns out that all the following words have the same value as each other: WE THREE KINGS OF ORIENT ARE. What are the values of A, N, S, W, E and R? WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 23 January. The Editor’s decision is final. Please send entries to Enigma 1729, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to [email protected] (please include your postal address). Answer to 1723 Four lots of dots: I drew 49 dots The winner Les Slow of Pocklington, East Yorkshire, UK
40 | NewScientist | 22/29 December 2012
From Dennis Altman, Institute for Human Security, La Trobe University As someone who in US terms would be a deep liberal, I was shocked to read Graham and Estes’ statement that: “As a rule, conservatives are more likely than liberals to prefer white people, straight people and high-status groups. Liberals are more comfortable… with members of ethnic and sexual minorities.” The implication is that all nonwhite, non-straight people are somehow outside the general population, which can be neatly divided into liberals and conservatives . Melbourne, Victoria, Australia
Pump it up From Chris Vivian, National Marine Adviser, Centre for Environment, Fisheries & Aquaculture Science In his letter on ocean thermal energy conversion (OTEC), Graham Cox suggests it could be used to fertilise surface waters with nutrient-rich deep water to promote plankton growth for carbon capture (1 December, p 31). However, there is a problem. Deep water often contains a lot of dissolved inorganic carbon from sinking organic matter which would be released by the process, and so would greatly reduce, if not eliminate, any benefits. This was indicated in research by Andrew Yool et al (Journal of Geophysical Research, vol 114, p C08009) and Andreas Oschlies et al (Geophysical Research Letters, vol 37, p L04701). Lowestoft, Suffolk, UK
Not so fruitful From Ed Manning In regard to your story on the impact of grapefruit on drugs (1 December, p 17), I was aware of its effect in connection with statins, but not more broadly. Given that it interferes with an enzyme that breaks down several drugs, would it not be desirable to combine grapefruit or its active component with some of these drugs in order to reduce the required dosages? New York, US The editor writes: n According to the researchers involved, this is not likely to improve drug therapeutics, and would likely complicate the clinical use of these medicines.
It is rocket science From Clive K. Semmens Elon Musk says that “with a nuclear thermal rocket, you could definitely reach a tenth of the speed of light” (1 December, p 27). Nonsense. The speed of light is 300,000 kilometres per second. The most heat-resistant material known (for the combustion chamber of such an engine) has a melting temperature of about 4300 kelvin. The mean velocity of hydrogen ions at about 4300 K is about 10 km/s – so that’s the highest possible exhaust velocity for a thermal rocket, whatever its energy source. This implies that the initial mass of a thermal rocket must be at least 2(v/10) where v is the final velocity in km/s. This is an inescapable lower bound, and in practice it would be much higher. To reach one-tenth of the speed of light (30,000 km/s), the initial mass of a thermal rocket is therefore at least 23000 times its final mass, or 10900 if you prefer. You could do a lot better, in theory, with a rocket with an ion drive, with its much higher
To join the debate, visit newscientist.com/letters
exhaust velocity – but one-tenth of the speed of light would still be cloud cuckoo land. Ely, Cambridgeshire, UK
The buyer pays From Peter Ryan If we wish to use the tax system to reduce greenhouse gas emissions, we need to avoid targeting industry, as happens in California and elsewhere (24 November, p 14). Instead, we should tax consumers based on the carbon footprint of the goods or services they are buying. This would reduce the opportunity for companies to avoid a carbon tax by moving their production facilities overseas. A carbon-added tax could work in a similar way to VAT, based on the final carbon footprint of goods or services. Ayr, UK
Money for Mars From Vincenzo Liguori Just in case there remain any doubts about NASA’s bias towards the Red Planet at the expense of everything else, another Mars rover is announced at a cost of $1.5 billion (15 December, p 8). This is after $2.5 billion for Curiosity, $500 million for the yet-to-be-
launched Mars Atmosphere and Volatile Evolution (MAVEN) mission and $425 million for the yet-to-be-launched Interior Exploration using Seismic
Investigations, Geodesy and Heat Transport probe (InSight). So, around $5 billion for Mars alone at a time when $2 billion for an orbiter for Neptune, or Jupiter’s moon Europa, or Saturn’s moon Titan could not be found. Even when someone came up with a mission to Titan’s lakes for $425 million, NASA chose InSight. Even though Mars seems ever less likely to be capable of sustaining life, I am not against its exploration. I like it. I would just like a more equitable distribution of scarce funds. I am also surprised that interested groups such as the Planetary Society don’t seem to have reacted; not a peep out of them as NASA announces more and more money on Mars while cutting the rest. Dee Why, New South Wales, Australia
Electric universe From Greg Shanahan When physicist Timothy Horbury says “everything we’ve seen [from the Voyager probe] is not what we expected to see”, he appears to be referring to standard cosmological models and their predictions for what the transit from our solar system to interstellar space should be like (newscientist.com, 4 December). Those influential in the nonstandard plasma cosmology field, such as physicists Anthony Peratt and Donald Scott, would be more surprised if the electromagnetism that Voyager has detected, and which has been described as a “magnetic highway”, was missing. If the measured electromagnetic fields are factored into the forces that govern galaxies, perhaps we can end the fruitless 20-year search for dark matter to explain how galaxies are held together, and let gravity take a back seat to electromagnetic effects. Rosebank, New South Wales, Australia
All aboard From Phil Bly The Japanese passenger train that is based on a roller-coaster is interesting. Since no motor is needed, it can be light and efficient, though it was noted that motorised vehicles can use
animal husbandry, and we started to “modify” food by selective breeding. Then we discovered how to alter genes in the lab. This suggests three label codes would suffice. GN (Genes Natural), SG (Selected Genes) and GM (Modified Genes). I believe that the proof of the pudding is in the eating, and I wish the GN-only fanatics the very best of luck. Donvale, Victoria, Australia.
Going forward
regenerative braking and may be just as energy efficient (8 December, p 22). However, it still operates as mass transport to many different destinations, so it must keep stopping, which wastes energy and time. There are ways of avoiding this, as exemplified by the Personal Rapid Transit system at Heathrow Airport in London. It uses small, automatic energyefficient driverless vehicles to carry people non-stop from origin to destination. It is strange that designers are still fixated on the traditional model of public transport, when automation can provide not only a higher level of personal service, but also greater energy efficiency. Monmouth, UK
Good taste gene From Derek Williams Even though Californians voted against mandatory labelling of genetically modified foods (17 November, p 28), it is worth considering the details of a suitable system. For a long time everything humans ate was “natural” food. Then came agriculture and
From Robert Dooman Roger Penrose and Stephen Hawking concluded that the big bang must truly be the beginning. As you discussed, we are left to figure out how the big bang occurred ex nihilo, without prior substance (1 December, p 34). The ancients wisely advised us to leave this line of inquiry to the Muses. Maybe we’d be better served investing our time in finding new vaccines instead of searching for where the beginning began. Chicago, Illinois, US
Time for change From Paddy Shannon In your editorial on North Korea you said that “the regime may be atrocious, but what its people need above all else is humanitarian aid” (24 November, p 5). At the risk of jeopardising my future invitation to Pyongyang to lecture on plain speaking, what they need above all else is drastic regime change. Lancaster, UK
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.
22/29 December 2012 | NewScientist | 41