- Email: [email protected]
Timber treatment
The last word– GROWTH POTENTIAL My new shower gel proclaims: “New! Stimulates skin flora.” Is there any benefit in this?
It sounds like advertising hype to me. Your “normal” flora don’t need any extra nutrition if your skin is in a generally healthy condition. Each distinct zone of healthy skin has its own stable, dominant flora and meddling with it is risky. The ideal flora for each zone form an even, adherent coating of a particular combination of strains that perform all sorts of different functions, such as tuning your personal and family varieties of body odour. It also crowds out or repels rival strains that might threaten your health. Over large areas of skin your normal beneficial flora form what amounts to a protective nonstick coating. Growing too vigorously does no good because overcrowding might cause them either to harm your skin or flake off, leaving footholds for alien pathogens. Furthermore, in microbial ecology one of the most important competitive weapons is the denial of
excess nutrients to your skin, that surplus might fuel an alien invasion. Jon Richfield Somerset West, South Africa
TIMBER TREATMENT It’s well known in wood-turning circles that a piece of wood which is a little soft or rotten can be brought back to a useful state by an overnight soaking in a 50:50 solution of water and washing-up liquid. It hardens the wood, enabling it to be gripped successfully in a lathe. What’s going on and why does it work?
The washing-up liquid is a surfactant, or wetting agent, which lowers the surface tension of the water, allowing it to spread through the wood more easily. The wood fibres swell as they become engorged with water, which makes the wood hard again. However, this is only a short-term solution for wood suffering from
Last Words past and present, plus a full list of unanswered questions, are available at www.newscientist.com/lastword
incipient (or surface-level) decay. It may harden the wood temporarily, but it will soon become soft again when it dries out. Further damage and softening is likely, because excessive moisture encourages the fungal organism Coniophora puteana – often referred to as cellar fungus – which leads to further decay. Jenny Brown Corpus Christi College Cambridge, UK
THIS WEEK’S QUESTIONS No use crying While making a cup of coffee, I spilt some milk and it made an interesting pattern. There were approximately 18 small droplets surrounding a larger central droplet (see Photo, below left). It reminded me of a photograph I saw in a textbook during my childhood, where a drop had just fallen into a glass of milk, resulting in a splash like a king’s
crown. Why did my pattern and the one from the book form? Presumably they are related. Do other liquids make similar patterns? Stephen Broderick Toowoomba, Queensland, Australia The best bits In a worst-case scenario, if one had to eat parts of oneself, which nonorgans would be the most nutritious? Nails? Hair? Earwax? David Klein Palmerston North, New Zealand Sand islands When walking along a beach in Mallorca in late April, I noticed some unusual patterns being cast on the seabed by small floating patches of sand (see Photo, below right). What causes the patches to form and why do their shadows on the seabed have bright fringes around the edges and around the gaps in the middle? Tim Pickles Brough, East Yorkshire, UK
“If your shower gel supplies excess nutrients to your skin, that surplus might fuel an alien invasion” food to rivals. Leukocytes in pus, for example, inhibit germs partly by absorbing iron, and therefore denying it to invasive bacteria and fungi. If your shower gel supplies Questions and answers should be kept as concise as possible. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and email address if you have one. Questions should be restricted to scientific enquiries about everyday phenomena. The writers of all published answers will receive a cheque for £25 (or the US$ equivalent). Reed Business Information Ltd reserves all rights to reuse question and answer material submitted by
readers in any medium or format. Send questions and answers to The Last Word, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, UK (fax +44 (0) 20 7611 1280), by email to [email protected] or visit www. newscientist.com/lastword.ns (please include a postal address in order to receive payment for answers). If you would like a list of all unanswered questions please send an SAE to LWQlist at the above address.
Memorable answer? The Last Word and New Scientist have teamed up with Crucial Technology (www.crucial.com/uk) and will be awarding each successful author a 512MB Gizmo! overdrive.
WHY DON’T PENGUINS’ FEET FREEZE? The latest collection from The Last Word, answering some of the world’s most baffling questions Available in bookstores and online at www.newscientist.com/lastword3.ns
It sounds like advertising hype to me. Your “normal” flora don’t need any extra nutrition if your skin is in a generally healthy condition. Each distinct zone of healthy skin has its own stable, dominant flora and meddling with it is risky. The ideal flora for each zone form an even, adherent coating of a particular combination of strains that perform all sorts of different functions, such as tuning your personal and family varieties of body odour. It also crowds out or repels rival strains that might threaten your health. Over large areas of skin your normal beneficial flora form what amounts to a protective nonstick coating. Growing too vigorously does no good because overcrowding might cause them either to harm your skin or flake off, leaving footholds for alien pathogens. Furthermore, in microbial ecology one of the most important competitive weapons is the denial of
excess nutrients to your skin, that surplus might fuel an alien invasion. Jon Richfield Somerset West, South Africa
TIMBER TREATMENT It’s well known in wood-turning circles that a piece of wood which is a little soft or rotten can be brought back to a useful state by an overnight soaking in a 50:50 solution of water and washing-up liquid. It hardens the wood, enabling it to be gripped successfully in a lathe. What’s going on and why does it work?
The washing-up liquid is a surfactant, or wetting agent, which lowers the surface tension of the water, allowing it to spread through the wood more easily. The wood fibres swell as they become engorged with water, which makes the wood hard again. However, this is only a short-term solution for wood suffering from
Last Words past and present, plus a full list of unanswered questions, are available at www.newscientist.com/lastword
incipient (or surface-level) decay. It may harden the wood temporarily, but it will soon become soft again when it dries out. Further damage and softening is likely, because excessive moisture encourages the fungal organism Coniophora puteana – often referred to as cellar fungus – which leads to further decay. Jenny Brown Corpus Christi College Cambridge, UK
THIS WEEK’S QUESTIONS No use crying While making a cup of coffee, I spilt some milk and it made an interesting pattern. There were approximately 18 small droplets surrounding a larger central droplet (see Photo, below left). It reminded me of a photograph I saw in a textbook during my childhood, where a drop had just fallen into a glass of milk, resulting in a splash like a king’s
crown. Why did my pattern and the one from the book form? Presumably they are related. Do other liquids make similar patterns? Stephen Broderick Toowoomba, Queensland, Australia The best bits In a worst-case scenario, if one had to eat parts of oneself, which nonorgans would be the most nutritious? Nails? Hair? Earwax? David Klein Palmerston North, New Zealand Sand islands When walking along a beach in Mallorca in late April, I noticed some unusual patterns being cast on the seabed by small floating patches of sand (see Photo, below right). What causes the patches to form and why do their shadows on the seabed have bright fringes around the edges and around the gaps in the middle? Tim Pickles Brough, East Yorkshire, UK
“If your shower gel supplies excess nutrients to your skin, that surplus might fuel an alien invasion” food to rivals. Leukocytes in pus, for example, inhibit germs partly by absorbing iron, and therefore denying it to invasive bacteria and fungi. If your shower gel supplies Questions and answers should be kept as concise as possible. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and email address if you have one. Questions should be restricted to scientific enquiries about everyday phenomena. The writers of all published answers will receive a cheque for £25 (or the US$ equivalent). Reed Business Information Ltd reserves all rights to reuse question and answer material submitted by
readers in any medium or format. Send questions and answers to The Last Word, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, UK (fax +44 (0) 20 7611 1280), by email to [email protected] or visit www. newscientist.com/lastword.ns (please include a postal address in order to receive payment for answers). If you would like a list of all unanswered questions please send an SAE to LWQlist at the above address.
Memorable answer? The Last Word and New Scientist have teamed up with Crucial Technology (www.crucial.com/uk) and will be awarding each successful author a 512MB Gizmo! overdrive.
WHY DON’T PENGUINS’ FEET FREEZE? The latest collection from The Last Word, answering some of the world’s most baffling questions Available in bookstores and online at www.newscientist.com/lastword3.ns