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Heavy metal
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THE LAST WORD Heavy metal Does a new MP3 player weigh less when it has no music on it? (Continued)
similar but there was no foam. What caused it and what changed overnight so that it disappeared?
n Sea foam or spume is created n An earlier reply in the 5 July as seawater is churned when issue regarding the weight of waves break on the shore. It is an MP3 player is misleading, more likely to happen when the although I agree with the water contains dissolved organic conclusion. matter, such as when algal blooms It implies that data bits are decompose. Compounds like stored by adding or removing these act as foaming agents, or electrons from a memory cell, surfactants, which trap air, and that these electrons are leading to the formation of longsupplied by a battery. In fact, bits lasting bubbles when the water is are stored by moving electrons whisked by wave action. from one part of the memory cell Wind blowing across the oceans to another, so there is no net gain can create foam-tipped waves, or or loss of electrons in the memory whitecaps, in a similar fashion. chip. The chip contains the same Assuming average sea-level wind number of electrons, and thus speeds, whitecaps should cover weighs the same, whether it’s all between 2 and 3 per cent of the 0s, all 1s or full of data. oceans at any one time – about the Likewise, when a battery same area as the US. supplies an electron from one According to climate scientists, pole it consumes one at the other. a warmer world should also be When the battery is flat it contains just as many electrons as when it “Assuming average wind speeds, whitecaps should was fully charged. No electronic cover up to 3 per cent of devices accumulate electrons; the oceans at any time” the flow in to the device is always balanced by flow out. windier, increasing the Doug Fenna percentage cover of whitecaps. Ryde, Isle of Wight, UK As white surfaces increase the amount of sunlight reflected back into space, this could provide a Foam home brake on warming. Indeed, an In winter I visited Tywyn in west increase in wind speed from 7 to Wales. Both the beach and the 9 metres per second is thought to promenade were covered in a mass of triple the percentage of sea foam blowing in from the sea. The sea surface covered by foam. was rough with waves driven by a Mike Follows strong wind and the foam covered the Sutton Coldfield, surface. The next day conditions were West Midlands, UK
The writers of answers that are published in the magazine will receive a cheque for £25 (or US$ equivalent). Answers should be concise. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and an email address if you have one. New Scientist retains total editorial control over the published content. Reed Business Information Ltd reserves all rights to reuse all question and answer material that has been
submitted by readers in any medium or in any format and at any time in the future. Send questions and answers to The Last Word, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, UK, by email to lastword@newscientist. com or visit www.newscientist.com/topic/ lastword (please include a postal address in order to receive payment for answers). Unanswered questions can also be found at this URL.
n Look at the ingredients on your bubble-bath or shampoo and you will see sodium lauryl sulphate or some other surfactant. These are foam stabilisers, which lower surface tension in water, allowing bubbles to last longer. When added to water and agitated, you get froth. The same is true in nature. Phytoplankton and algae produce chemicals that can act as surfactants and when algal blooms decay, these natural foaming agents are released into the sea. Stormy conditions add the agitation needed for sea foam to form and onshore gales bring it onto the beach. Foams are inherently unstable and only persist when they form faster than they dissipate. When the wind lessens and the waves diminish, or the concentration of the natural surfactant drops, the foam disappears.
David Muir Science Department Portobello High School, Edinburgh, UK
This week’s questions Beach balls
What could have caused these soft little balls of beach sand (see photo) to form? There were huge numbers of them stretched along about 700 metres of this beach about 100 kilometres north of Auckland. David Goldkorn Auckland, New Zealand Leather and steel
As a boy I watched my grandfather sharpen his cut-throat razor on a leather strap. How did this work? Phill Wells Windsor, Berkshire, UK
Will we ever speak dolphin? The latest book: packed full of wit, knowledge and extraordinary discovery Available from booksellers and at newscientist.com/dolphins
THE LAST WORD Heavy metal Does a new MP3 player weigh less when it has no music on it? (Continued)
similar but there was no foam. What caused it and what changed overnight so that it disappeared?
n Sea foam or spume is created n An earlier reply in the 5 July as seawater is churned when issue regarding the weight of waves break on the shore. It is an MP3 player is misleading, more likely to happen when the although I agree with the water contains dissolved organic conclusion. matter, such as when algal blooms It implies that data bits are decompose. Compounds like stored by adding or removing these act as foaming agents, or electrons from a memory cell, surfactants, which trap air, and that these electrons are leading to the formation of longsupplied by a battery. In fact, bits lasting bubbles when the water is are stored by moving electrons whisked by wave action. from one part of the memory cell Wind blowing across the oceans to another, so there is no net gain can create foam-tipped waves, or or loss of electrons in the memory whitecaps, in a similar fashion. chip. The chip contains the same Assuming average sea-level wind number of electrons, and thus speeds, whitecaps should cover weighs the same, whether it’s all between 2 and 3 per cent of the 0s, all 1s or full of data. oceans at any one time – about the Likewise, when a battery same area as the US. supplies an electron from one According to climate scientists, pole it consumes one at the other. a warmer world should also be When the battery is flat it contains just as many electrons as when it “Assuming average wind speeds, whitecaps should was fully charged. No electronic cover up to 3 per cent of devices accumulate electrons; the oceans at any time” the flow in to the device is always balanced by flow out. windier, increasing the Doug Fenna percentage cover of whitecaps. Ryde, Isle of Wight, UK As white surfaces increase the amount of sunlight reflected back into space, this could provide a Foam home brake on warming. Indeed, an In winter I visited Tywyn in west increase in wind speed from 7 to Wales. Both the beach and the 9 metres per second is thought to promenade were covered in a mass of triple the percentage of sea foam blowing in from the sea. The sea surface covered by foam. was rough with waves driven by a Mike Follows strong wind and the foam covered the Sutton Coldfield, surface. The next day conditions were West Midlands, UK
The writers of answers that are published in the magazine will receive a cheque for £25 (or US$ equivalent). Answers should be concise. We reserve the right to edit items for clarity and style. Please include a daytime telephone number and an email address if you have one. New Scientist retains total editorial control over the published content. Reed Business Information Ltd reserves all rights to reuse all question and answer material that has been
submitted by readers in any medium or in any format and at any time in the future. Send questions and answers to The Last Word, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, UK, by email to lastword@newscientist. com or visit www.newscientist.com/topic/ lastword (please include a postal address in order to receive payment for answers). Unanswered questions can also be found at this URL.
n Look at the ingredients on your bubble-bath or shampoo and you will see sodium lauryl sulphate or some other surfactant. These are foam stabilisers, which lower surface tension in water, allowing bubbles to last longer. When added to water and agitated, you get froth. The same is true in nature. Phytoplankton and algae produce chemicals that can act as surfactants and when algal blooms decay, these natural foaming agents are released into the sea. Stormy conditions add the agitation needed for sea foam to form and onshore gales bring it onto the beach. Foams are inherently unstable and only persist when they form faster than they dissipate. When the wind lessens and the waves diminish, or the concentration of the natural surfactant drops, the foam disappears.
David Muir Science Department Portobello High School, Edinburgh, UK
This week’s questions Beach balls
What could have caused these soft little balls of beach sand (see photo) to form? There were huge numbers of them stretched along about 700 metres of this beach about 100 kilometres north of Auckland. David Goldkorn Auckland, New Zealand Leather and steel
As a boy I watched my grandfather sharpen his cut-throat razor on a leather strap. How did this work? Phill Wells Windsor, Berkshire, UK
Will we ever speak dolphin? The latest book: packed full of wit, knowledge and extraordinary discovery Available from booksellers and at newscientist.com/dolphins