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SILICON SILIC CHIP www.siliconchip.com.au Publisher & Editor-in-Chief Leo Simpson, B.Bus., FAICD Production Manager Greg Swain, B.Sc. (Hons.) Technical Editor John Clarke, B.E.(Elec.) Technical Staff Ross Tester Jim Rowe, B.A., B.Sc Mauro Grassi, B.Sc. (Hons), Ph.D Photography Ross Tester Reader Services Ann Morris Advertising Enquiries Glyn Smith Phone (02) 9939 3295 Mobile 0431 792 293 glyn<at>siliconchip.com.au Regular Contributors Brendan Akhurst Rodney Champness, VK3UG 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 is 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: $94.50 per year in Australia. For overseas rates, see the order form 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 Low sunspot activity presages solar cooling Years ago, when I was at the helm of Electronics Australia magazine, we used to publish “Ionospheric Predictions” every month for the benefit of amateur radio operators. In essence, these predictions help users of shortwave radio make the best use of the radio spectrum. Whether or not certain bands are going to be “open” for use depends on ionospheric activity which is related to solar flares. Yes, yes, I can imagine that most of you are already nodding off. Which is why EA eventually stopped publishing the ionospheric predictions. But Australia’s Ionospheric Prediction Service (IPS – part of the Bureau of Meteorology) still provides this information (see www.ips.gov.au). So who cares? Well, maybe you should. Because even if you have no interest at all in shortwave communications, you do have a considerable vested interest in whether world communications are at risk. And they always are at risk from solar flares. Now that we are all so inextricably linked together via the internet, mobile phones, satellite comms and so on, the world has a truly enormous investment which is at the mercy of Old Sol. A big solar flare could literally wipe out much of this network. This may be hard to comprehend but the biggest ever observed solar flare, in 1859, shorted out telegraph wires, causing fires in North America and Europe, sent readings of Earth’s magnetic field soaring, and produced northern lights so bright that people could read newspapers by their light. As it happened, apart from telegraph wires, there were no communications services in 1859. Today, such a severe solar flare would do unimaginable damage to electricity grids, as well as most communications services, phones, all radio and TV – you name it. If it happened, you could forget Facebook, online banking and virtually every other activity which involves electronic communication – and it could take quite a while, maybe weeks or months, to restore everything! Is such a scenario likely? We don’t really know but we do know that we are heading into another peak of solar activity, in 2013 – just four years away. Let us hope that all those companies who have large direct investments in communications are doing all they can to “harden” their systems against solar flares. Solar flares can occur at any time and they are closely associated with sun spots – Earth-sized or larger blotches on the sun marking areas of heightened magnetic activity. As a matter of fact, in preparation for writing this editorial, initially on the topic of communications risk, I decided to check the number of visible sunspots (using binoculars and projection onto a white screen). I was astonished to find no sunspots at all! Checking on a number of websites confirmed this – sunspots are currently at a record low. Furthermore, the peak of the next cycle, Solar Cycle 24, in 2013, is predicted to be the lowest since Solar Cycle 16 in 1928 and ninth weakest since the 1750s, when numbered cycles began. All of which means that the probability of a big solar flare any time soon is fairly low and the risk to communications is also low. Good news, you might think but that could be utterly wrong. There is something far more serious to worry about. In fact, there is a strong correlation between sunspot activity and solar output. Old Sol could be heading into a long period of low activity and that could mean pronounced global cooling! Apparently, we have been through this many times before, the most recent being the Little Ice Age which came after the Middle Ages warming period. Two pronounced periods of global cooling have been noted in the Little Ice Age – the Maunder Minimum (1645 - 1715) and the Dalton Minimum (1790 - 1820). Both of these corresponded with long periods of low sunspot activity. Well boys and girls, I don’t know about you but I would much prefer to be anticipating global warming rather than cooling. We are going to be disappointed though. If past history is any guide, global warming is good for humans, with increased food production and economic activity. Global cooling, on the other hand, means increased misery. Polar bears should be OK though. Leo Simpson siliconchip.com.au