| Observatory: On Birds of Many Colors, Lice Dress the Part Researchers have found that light-colored lice live on light-colored birds, whereas dark-colored lice live on dark-colored birds. feeds.nytimes.com |
Letters: Lovely but Lethal (1 Letter) A letter to the editor. feeds.nytimes.com |
A Nobel prize - but not for levitating frogs | Jon Butterworth Congratulations to Andre Geim and Konstantin Novoselov on winning the Nobel prize in physics – not for their frog-levitating work, but for groundbreaking studies of grapheneI'd heard about graphene before, but as a particle physicist it's not something I'm an expert on. Although I have reservations about prizes in general, it is always good to see great physics and outstanding physicists in the news, and it's a good excuse to educate myself about neighbouring subfields. So here you go ...Graphene is a material made of a single layer of carbon atoms. Actually, graphite is made of many such layers stacked on top of each other, very tightly bound within the layer, but with the layers loosely bound to each other. This is why graphite has such a curious mixture of properties: it's hard and slippery, but good for drawing on pavements with.Geim and Novoselov successfully isolated single layers of graphite – graphene – large enough for its properties to be studied. Graphene is transparent, electrically conducting, flexible, stretchable and, weight for weight, much stronger than steel. According to the summary on the Nobel website a hypothetical graphene hammock would be strong enough to hold a cat, but would weigh about the same as one of its whiskers. It's not too hard to imagine a lot of more lucrative applications.Understanding the physics of a real two-dimensional crystal solid both uses and potentially demonstrates some very interesting quantum mechanics and relativity. For example, there is an effect called the Klein paradox where fast-moving electrons can penetrate a super-high-energy barrier because they create matter-antimatter pairs. In some ways, electrons in graphene behave as though they are massless, and so pairs can be very easily produced and the relativistic effect can perhaps be demonstrated even with slow electrons and lower energy barriers.As a Mancunian by upbringing I'm very pleased that Geim and Novoselov work there. The fact that we have such brilliant scientists in UK universities is testament to the high quality of our research environment, and the long-term investment it has received. I can't resist the opportunity to yet again urge that we don't throw it all away in a series of misguided cuts.Geim is also well known (or as his web page puts it "notorious") for levitating frogs. This is a demonstration of the peculiar fact that all materials have some magnetism, albeit very weak in most cases, and that if you put them in a high enough magnetic field you can see the effects – and make them fly. Why frogs? Well, no frogs were harmed in the experiments. But also, magnetism is a hugely important topic in physics that can seem a little dry to students, and as the physicists put it:... the frog picture will probably help students studying magnetism to get less easily bored. Anyway, it's an unrelated example of how cool condensed matter physics can be. The serious business is graphene. Well deserved congratulations to them both.Jon Butterworthguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Iranian FM: Ready to resume nuclear talks soon By SLOBODAN LEKIC 2010-10-15T12:46:58ZBRUSSELS (AP) -- Iranian Foreign Minister Manouchehr Mottaki said on Friday that Tehran was ready to resume talks about its nuclear program with the international community within a matter of weeks.... hosted.ap.org |
British barn owls rely on humans Three quarters of British barn owls now live in man-made nest boxes, according to conservationists. news.bbc.co.uk |