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SILICON CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc.(Hons.) Technical Editor Peter Smith Technical Staff John Clarke, B.E.(Elec.) Ross Tester Jim Rowe, B.A., B.Sc, VK2ZLO Reader Services Ann Jenkinson Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG Kevin Poulter Mike Sheriff, B.Sc, VK2YFK Stan Swan SILICON CHIP is published 12 times a year by Silicon Chip Publications Pty Ltd. ACN 003 205 490. ABN 49 003 205 490 All material copyright ©. No part of this publication may be reproduced without the written consent of the publisher. Printing: Hannanprint, Noble Park, Victoria. Distribution: Network Distribution Company. Subscription rates: $89.50 per year in Australia. For overseas rates, see the subscription page in this issue. Editorial office: Unit 1, 234 Harbord Rd, Brookvale, NSW 2100. Postal address: PO Box 139, Collaroy Beach, NSW 2097. Phone (02) 9939 3295. Fax (02) 9939 2648. E-mail: silicon<at>siliconchip.com.au ISSN 1030-2662 * Recommended and maximum price only. 2  Silicon Chip Publisher’s Letter Earth Hour – a flawed concept On the evening of March 31st 2007, Sydneysiders have been invited to turn off their lights for one hour, to demonstrate the deleterious effects of outdoor lighting on the night sky and to draw attention to energy conservation and reduction of greenhouse gases. The idea was put forward by the World Wildlife Fund. On the face of it, this is a great idea. As with just about every major city in the world, Sydney unnecessarily radiates vast amounts of heat and light up into the stratosphere every night. Outdoor lighting is just the visible component of that waste and if we can do it on one night, even if only briefly, it might set a precedent which could be greatly extended. If building owners, businesses and ordinary residences can be persuaded to cut unnecessary outdoor lighting, we will cut energy wastage and also allow people to become a little more familiar with Sydney’s spectacular bight skies. After all, the vast majority of the population would not be able to identify the Southern Cross or any of the far more prominent constellations. However, while the idea of Earth Hour is good, the timing of it is just silly. Earth Hour is supposed to run from 7.30-8.30pm. But 7.30pm is not long after sunset on that evening so it will not be totally dark at that time. Worse still, the Moon rises at 5.41pm that evening and at that stage of the month, it is only two days away from full moon. So any effect of sky darkening by turning lights off that evening will be largely negated by a big bright moon. Perhaps the WWF and the other promoters of Earth Hour should have consulted with Sydney Observatory before putting the idea forward! The ideal time to have Earth Hour would have been to run from say 9.00-10.00pm (if indeed, it has to be confined to one hour) and to have it about time of New Moon. That way we could have a much better appreciation of the effect of cutting outdoor lighting. In the meantime, if you want to get the effect yourself, just take a trip some 100km away from major cities and towns anywhere in Australia and then you can see a real dark sky, with all the beauty of the firmament fully revealed. Longwall mining: an environmental disaster In writing last month’s editorial commenting on Ziggy Switkowski’s report on nuclear power, I was conscious that there was very little on the environmental hazards of coal mining in the report. I thought that these should have been emphasised if Switkowski was really trying to promote nuclear power. In fact, I went looking for reports on the environmental impacts of open-cut coal mining but could find little that was really controversial. However, just after I wrote that editorial, I was referred to the release of a new report on longwall coal mining in NSW, commissioned by the Total Environment Centre. Entitled, “Impacts of Longwall Coal Mining on the Environment in NSW”, it sets out the appalling damage to rivers, creeks and the water table in general which occurs when longwall mining is performed. Furthermore, it details the damage to Sydney’s water catchment at a time when the NSW government should have been doing everything possible to ensure Sydney’s water supply. But the blame cannot be all sheeted home to the mining companies. Their activities are permitted by the NSW government, at the same time as it has collected hundreds of millions of dollars in mining royalties. Frankly, it makes all the NSW government’s announcements and policies relating to the State’s water resources seem utterly hypocritical. You can download the complete report from www.tec.org.au For those opposed to the burning of fossil fuels in power stations, to coal mining and the export of coal, it is damning evidence and another factor which is favourable to the future generation of nuclear power in Australia. Leo Simpson siliconchip.com.au