Stardate: Friday 10th March 2006 Issue 173

Why bother with heads or tails, says top science telly producer Jonathan Sanderson,  when you can have heads AND tails spinning in a blur in front of your eyes?

Empty your purse, here comes a penny-tastic demonstration.

You will need:

• Some 1p coins
• A drinking straw
• A magnet (even a fridge magnet may do the job)

What to do:

1. Hold the magnet out in front of your face, and hang a penny from it by its edge. If the penny doesn't stick, you've either got the worst magnet in the world, or a non-magnetic penny. Try another one of whichever seems more likely.
2. Now take another penny, and hang that from the first one. Join them by their edges, so you're making a chain of pennies dangling from the magnet. Depending on the strength of your magnet, you might be able to make a longer chain; keep going until the last penny only just clings on.
3. This is where your straw comes in. Very gently, blow through it at the last penny in the chain. Blow to one side, and you should be able to make the coin spin. As it spins faster and faster, you can blow harder and harder, and you should be able to make it whizz around at speeds that must be absolutely terrifying to all penny-kind.

What's going on:

The very last coin in the chain is barely held by the previous one, and they touch only at the tiny spot where their rims meet. As a result, there's only a very small amount of friction acting on the penny when it spins - the most important forces acting on it are you blowing at it, and it having to push the air out of the way so it can spin.

If you think about spinning a coin on a table, there's the same air resistance acting to slow it down, but also lots of friction as it slips and rolls over the tabletop. So the magnetically-suspended coin spins far, far faster, and for much, much longer.

I've no idea how much faster it spins. Three times? Six times? Eighteen times? If your school has a strobe lamp, you might be able to work it out - let me know if you manage it!

			Whole School Activity for National Science Week Bird flu appears to be approaching Britain, and fears are rising. How dangerous is the situation? Could millions be killed? To help students understand how viral diseases spread, the ASE (Association for Science Education) have developed a 5-day simulation activity that can involve large numbers of students – and without a doubt get their full attention. Find it here

			In Search of the next Bill Bryson? Know any budding young science communicators? If so, here’s an opportunity for them to show off their talents … Part funded by royalties from Bill Bryson’s hit book, ‘A Brief History of Nearly Everything’, The Royal Society for Chemistry has just launched a competition for UK / Ireland school pupils aged 5-18. Entrants can submit work in any format, on any scientific topic, and there are two age groups, primary and secondary school. The prize is a heady combination of prestige and CASH, for both schools and students. So check the details at www.rsc.org/billbrysonprize and get your students on the case!

			Click for Climate Change What better week to make a pledge that’ll help the environment? The British Association and the ESRC. have just launched a new campaign, Click for the Climate. To get involved, all you have to do is make one or more changes to your lifestyle that will help cut carbon emissions. It could be a small change, like not leaving the tv on standby, but you’ll be part of an army of pledges who can achieve valuable results if everyone does their bit …

			Climate Change Champions And finally, here’s another idea for encouraging people to help combat global warming. It’s a competition being hosted by DEFRA for 10-18 years olds, to find nine ‘champions’ to spread the environmental word throughout their local community. The prize includes a trip to Switzerland … Full details can be found at: http://www.defra.gov.uk/news/latest/2006/climate-0126.htm

			Democs CPD Events We’ve featured Democs before. They’re curriculum tools developed by the New Economics Foundation  to help clue young people up on a range of current scientific issues and facilitate discussion sessions. The kits are free to download, and to maximise their value, a number of CPD events have now been organised. Here are the dates/places: London - Monday 20th March, 4.30-7.30pm Derby  - Thursday 16th March, 10-4.30pm contact philip.brown@the-ba.net for more information. Glasgow - 30th of March, 10-4.30pm in Glasgow – contact elsa.ekevall@bes8t.co.uk for more information. For more info on Democs visit www.neweconomics.org/gen/democs.aspx and to find out how to get hold of a copy visit www.neweconomics.org/gen/howtogetholdofdemocs.aspx Freebie alert! There are free CDs for the first ten people to email with the correct number of Democs kits that have been developed. Know the answer? Email elsa.ekevall@bes8t.co.uk. Don’t know the answer? Have a look at the website, then email her!

			Glasgow first. Alice Through The Looking Glass is a huge and mind-bending new exhibition on the science of illusion at the Glasgow Science Centre. It’s set in the weird world of Lewis Carroll’s imagination where things are never quite as they seem … but as visitors discover, in the ‘real’ world, such illusions can often be explained by a bit of brain science. Featuring, amongst other things, the work of perceptual psychologists Professor Richard Gregory* and Dr R.Beau Lotto, the exhibition will have you laughing while you scratch your head, rub your eyes and mutter, “Eh?”, It’s a highly recommended day out, and we have four family passes to give away. To get into the draw, send an email entitled THROUGH THE LOOKING GLASS to planet-science.news@nesta.org.uk. Please include your name and address. * for more illusional treats from Professor Gregory, have a look at RWW below.

			1001 Inventions – Books and Posters Meanwhile, at the Museum of Science and Industry in Manchester, there’s another brand new exhibition, this one exploring the huge influence that Muslim science, technology and innovation has had on every aspect of our world today.  Did you know, for example, that cheese, algebra, carpets, chess, cataract operations and do-re-mi-fa-sol-la-ti-do all originated in the Muslim world? Or that this powerhouse of scientific exploration also made a wealth of discoveries about the natural world and the mathematics that underpins it? The exhibition is free, and includes workshops, special events and shows. There’s also an info-packed website at www.1001inventions.com with a downloadable teachers’ pack. The only things that are not absolutely free are the accompanying ‘1001 Inventions’ book (worth £25) and the collection of beautiful posters, but we have three sets of these to give away to Planet Science readers. To get into the draw for a book and poster set, send an email entitled ‘1001 INVENTIONS’ to planet-science.news@nesta.org.uk with a note of your name and address.

‘Did you know that many of the foods you eat are laced with a highly toxic contaminant? Forget E-numbers, aflatoxins constitute a much more serious threat to food safety. These substances are mycotoxins produced by two types of fungus (moulds), called Aspergillus flavus and Aspergillus parasiticus, and they affect a multitude of food crops around the world, such as peanuts, tree nuts (e.g. almonds, brazil nuts), corn, wheat, oil seeds (e.g. cotton seed), and some spices.

Milk, dairy products, meat and eggs can also be affected, because this is where aflatoxins in contaminated animal feed end up. This can be a serious problem, especially in developing countries, where there may be a lack of control and in addition to environmental factors which help the aflatoxin to form.

There are two types of aflatoxin poisoning – acute aflatoxicosis and chronic aflatoxicosis. The acute form, which can cause death, particularly in young children, is caused by ingesting large doses of aflatoxin (in excess of 6000mg). This is thankfully very rare in developed countries, due to screening of crops and sophisticated storage facilities. Chronic aflatoxicosis, a result of frequent, low-level consumption of contaminated foodstuffs, may on the other hand be quite common, possibly even in developed countries, although it’s rarely diagnosed because there are no specific symptoms. Sufferers are afflicted by impaired nutrient absorption, slow growth and also cancer - aflatoxins are known to be carcinogenic.

You may be wondering why aflatoxins aren’t headline news every night on tv. The reason is that they’re considered unavoidable contaminants, and in developed countries such as the UK, testing procedures are routine and strict. Any products with excessive aflatoxin levels are detected and stopped.

The latest aflatoxin contamination alert was issued by the UK Food Standards Agency (FSA) on 3 February 2006, involving a kebab powder made in Ghana. Such alerts happen frequently, and the affected products are then recalled from shops. Large supermarkets react very quickly to withdraw such products from their shelves, but if you were to trail round several small corner shops with a list of recalled products, chances are, you’d find some of them still sitting on their shelves. Go check out the FSA’s food alert page and see what you can find! http://www.food.gov.uk/enforcement/alerts/

			Revision Decision Ian Francis, our in-house teaching guru, has been surfing the web again for quality revision sites, and this week it’s a biology site that gets his seal of approval: Biotopics http://www.biotopics.co.uk/conten.html Don’t be put off by the enormity of this page, says Ian. The sections of the exam specification are colour-coded and you can always search within the page using ‘ctrl - f’. Look out for interactive features throughout the site when your cursor hovers over certain places on the page and neat things happen. And if your attention starts to flag, check out the collection of ‘howlers’ (daft answers given by pupils) at http://www.biotopics.co.uk/howl/index.html, have a secret chuckle at their expense (and hopefully not make similar mistakes when you’re in the same position). Sample nice-but-dim answer: ‘Pine is an example of a carnivorous tree.’ While concentrating on key stage 4 biology, this site should be useful for students at key stage 3 and A level too. Bookmark it now before you forget! Just point your browser at http://www.biotopics.co.uk/

			Richard Gregory http://www.richardgregory.org He’s one of the UK’s most eminent psychologists, as well as a media star and fabbo raconteur … As a great populariser of science too, Richard Gregory naturally has his own website. A small selection of his publications on perception can be found there - but why linger in the world of prose when there are Quicktime movies of three classic visual illusions to be savoured? Try the do-my-eyes-deceive me Ames Window - and the wooooogly wonder of the inside out face … Then have a cup of tea while you let your eyes un-boggle.