Fret ye not
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THE LAST WORD Temporal teaser The clock on an inexpensive radio in my bedroom ran so fast that I had to reset it at least monthly. In the end, I moved it to a less-used spare bedroom and bought a replacement. The first one now seems to keep time just as well as the new clock. Why? How? Thanks to Jeremy Greenway of Bacup, Lancashire, UK, for his suggestion that we should have looked across the page to Feedback for the answer to this. He wonders if our correspondent has recently “bought a set of Pyramidal Memories Transmutation tubes, or something similar, to fully hydrate your waters and optimise your tachyonic flow?” Nice try Jeremy, but no cigar – Ed n Cheap clock radios plugged into the mains electricity supply tend to count the number of cycles in the supply and use this to keep time. However, any interference to these cycles or to the clock can make them speed up. In our bedroom we have two identical clock radios. The one on my side of the bed gains 20 minutes a month, the other doesn’t. If we swap them, the one on my side still gains and the other doesn’t. The reason for this is that my side is less than a metre from a dimmer switch that produces enough electrical noise to cause a problem. I’d hazard a guess that your correspondent has a dimmer switch near the radio in the bedroom but not the spare room. If there is no dimmer or other obvious source of noise, such as an automatic tea-maker, you should get the wiring checked. Tom Potts Holsworthy Beacon, Devon, UK n If it has a digital display, the aberrant clock probably uses the 50-hertz mains frequency as its timing reference, detecting the number of times the sine wave of the frequency passes through zero volts. It may be connected to a supply that has something else on the same branch circuit, which introduces an electrical disturbance that generates multiple extra “zero crossings”, causing the clock to run fast. If the clock has an analogue display, the cause may be similar but the electrical disturbance distorts the sine wave, causing harmonic frequencies that confuse the motor. The supply to the spare room is probably on a separate branch that suffers no disturbance. The new clock either has better immunity to disturbance or uses a crystal oscillator for its timing reference, independent of the mains supply. John Woodgate Rayleigh, Essex, UK n This question came from Australia, a country with a hot climate. It is possible that one room is air-conditioned, but the air-conditioning is switched off in the spare room, so it’s hotter there. Battery-powered clock radios are regulated by vibrating quartz crystals. These expand and contract depending on the temperature and can cause clocks to run faster or slower. Ralph Hancock London, UK Sharpen up Why is the smell of pencil shavings so distinctive? I really like it, especially when they heat up as the sun comes through my classroom window. n An important property of a good-quality pencil is that it doesn’t splinter when sharpened. Red cedar wood has this property and was the wood of choice for pencil manufactures during the 19th and early 20th centuries. Dwindling supplies of this tree forced manufacturers to turn to incense cedar in the 1940s and this is what many pencils are still made of today. Incense cedar has excellent “sharpenability” and, as the name suggests, has a wonderful aroma. Cedar trees have evolved to produce a cocktail of chemical compounds that includes cedrol and cedrene. This concoction can act as a protection against pests, bacteria and fungi. When a pencil is sharpened, this mix is released from the wood and the sun’s heat increases the evaporation of the aromatics, enhancing the odour. The limbic system of your brain is involved in aspects of olfaction, emotion and long-term memory. This helps to explain how, decades later, the evocative smell of pencil sharpenings can stimulate memories of your class and frame of mind when you first breathed in cedar’s heady bouquet. A poor man’s potpourri of pencil shavings and spices sitting on a radiator can elevate the spirit during winter’s dark days. David Muir Science department Portobello High School Edinburgh, UK This week’s questions STAR QUALITY Stars appear as dots of bright light in the night sky. As with our sun, every star represents an immense light source that is dazzling close up. So given the brightness of stars, why are the intervening spaces, viewed from Earth, black? Graham Mays By email, no address supplied FRET YE NOT Living by the south coast of England, sea mists or frets are a common weather phenomenon. As the cold mist rolls off the sea and inland, it is accompanied by a notably intense marine, seashore smell. How does this smell get into the mist? The conditions are almost always calm, so there are no waves to form spray droplets. Ian Cairns Seaford, East Sussex, UK “Any interference to the mains-electricity supply cycles can make a cheap clock radio speed up” Last words past and present at newscientist.com/topic/lastword Win £100 by answering our monthly question about energy issues. How much electricity could be generated if you attached a turbine to the pressurised water supply coming into your home? Would this affect the water supplier or your neighbours? Answers should reach us by 2359 GMT on 12 November 2013 to [email protected] or visit www.newscientist.com/topic/ energy, where you will also find our terms and conditions. THE LAST WORD ON ENERGY sponsored by The writers of answers 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. Include a daytime telephone number and email address if you have one. We are pleased to acknowledge financial support from Statoil in producing The Last Word. New Scientist retains total editorial control over the content. Reed Business Information Ltd reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format. 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.
Transcript of Fret ye not
THE LAST WORD
Temporal teaserThe clock on an inexpensive radio in my bedroom ran so fast that I had to reset it at least monthly. In the end, I moved it to a less-used spare bedroom and bought a replacement. The first one now seems to keep time just as well as the new clock. Why? How?
Thanks to Jeremy Greenway of Bacup, Lancashire, UK, for his suggestion that we should have looked across the page to Feedback for the answer to this. He wonders if our correspondent has recently “bought a set of Pyramidal Memories Transmutation tubes, or something similar, to fully hydrate your waters and optimise your tachyonic flow?” Nice try Jeremy, but no cigar – Ed
n Cheap clock radios plugged into the mains electricity supply tend to count the number of cycles in the supply and use this to keep
time. However, any interference to these cycles or to the clock can make them speed up. In our bedroom we have two identical clock radios. The one on my side of the bed gains 20 minutes a month, the other doesn’t. If we swap them, the one on my side still gains and the other doesn’t.
The reason for this is that my side is less than a metre from a
dimmer switch that produces enough electrical noise to cause a problem. I’d hazard a guess that your correspondent has a dimmer switch near the radio in the bedroom but not the spare room. If there is no dimmer or other obvious source of noise, such as an automatic tea-maker, you should get the wiring checked.Tom PottsHolsworthy Beacon, Devon, UK
n If it has a digital display, the aberrant clock probably uses the 50-hertz mains frequency as its timing reference, detecting the number of times the sine wave of the frequency passes through zero volts. It may be connected to a supply that has something else on the same branch circuit, which introduces an electrical disturbance that generates multiple extra “zero crossings”, causing the clock to run fast.
If the clock has an analogue display, the cause may be similar but the electrical disturbance distorts the sine wave, causing harmonic frequencies that confuse the motor. The supply to the spare room is probably on a separate branch that suffers no disturbance. The new clock either has better immunity to disturbance or uses a crystal oscillator for its timing reference, independent of the mains supply.John WoodgateRayleigh, Essex, UK
n This question came from Australia, a country with a hot climate. It is possible that one
room is air-conditioned, but the air-conditioning is switched off in the spare room, so it’s hotter there. Battery-powered clock radios are regulated by vibrating quartz crystals. These expand and contract depending on the temperature and can cause clocks to run faster or slower. Ralph HancockLondon, UK
Sharpen upWhy is the smell of pencil shavings so distinctive? I really like it, especially when they heat up as the sun comes through my classroom window.
n An important property of a good-quality pencil is that it doesn’t splinter when sharpened. Red cedar wood has this property and was the wood of choice for pencil manufactures during the 19th and early 20th centuries. Dwindling supplies of this tree forced manufacturers to turn to incense cedar in the 1940s and this is what many pencils are still made of today. Incense cedar has excellent “sharpenability” and, as the name suggests, has a wonderful aroma.
Cedar trees have evolved to produce a cocktail of chemical compounds that includes cedrol and cedrene. This concoction can act as a protection against pests, bacteria and fungi. When a pencil is sharpened, this mix is released from the wood and the sun’s heat increases the evaporation of the aromatics, enhancing the odour.
The limbic system of your brain is involved in aspects of olfaction, emotion and long-term memory. This helps to explain how, decades later, the evocative smell of pencil sharpenings can stimulate memories of your class and frame of mind when you first breathed in cedar’s heady bouquet. A poor man’s potpourri of pencil shavings and spices sitting on a radiator can elevate the spirit during winter’s dark days.David MuirScience departmentPortobello High SchoolEdinburgh, UK
This week’s questionsSTar qualiTyStars appear as dots of bright light in the night sky. As with our sun, every star represents an immense light source that is dazzling close up. So given the brightness of stars, why are the intervening spaces, viewed from Earth, black?Graham MaysBy email, no address supplied
FreT ye noTLiving by the south coast of England, sea mists or frets are a common weather phenomenon. As the cold mist rolls off the sea and inland, it is accompanied by a notably intense marine, seashore smell. How does this smell get into the mist? The conditions are almost always calm, so there are no waves to form spray droplets.Ian CairnsSeaford, East Sussex, UK
“any interference to the mains-electricity supply cycles can make a cheap clock radio speed up”
last words past and present at newscientist.com/topic/lastword
Win £100 by answering our monthly question about energy issues.
How much electricity could be generated if you attached a turbine to the pressurised water supply coming into your home?Would this affect the water supplier or your neighbours?Answers should reach us by 2359 GMT on 12 November 2013 to [email protected] or visit www.newscientist.com/topic/energy, where you will also find our terms and conditions.
The lasT Word on energy
sponsored by
The writers of answers 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. Include a daytime telephone number and email address if you have one. We are pleased to acknowledge financial support from Statoil in producing The Last Word. New Scientist retains total editorial control over the content.
Reed Business Information Ltd reserves all rights to reuse question
and answer material that has been submitted by readers in any medium or in any format.
Send questions and answers to The Last Word, New Scientist, Lacon House, 84 Theobald’s Road, London WC1X 8NS, UK, by email to [email protected] 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.
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