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By James Dacey
“In the beginning there was light – the Big Bang,” said Steve Chu, talking on Monday at the UNESCO headquarters in Paris during the opening ceremony of the International Year of Light and Light-based Technologies (IYL 2015). Chu – a Nobel-prize winner and former US energy secretary – was among a smorgasbord of speakers at the two-day event, which brought together scientists, artists, politicians and many others with a particular interest in light and its applications.
Being a journalist, I was at the event with my own light-based technology, the humble SLR camera. I was recording a series of interviews with people at the event, including Chu, to get their thoughts on what the year of light means to them. As I’ve mentioned in a previous article, the fact that “light” is such an all-encompassing theme can also make it difficult to get a handle on what IYL 2015 is all about. I hope that the resulting video – to be published on physicsworld.com next week – will bring clarity to some of the initiatives and projects in the spotlight this year.
One of the people I caught up with is John Dudley, head of the international steering committee for IYL 2015. I laid down an unenviable challenge for Dudley of explaining what IYL 2015 is all about in 20 seconds or less – see his response in the video clip above.
Other people I caught up with spoke about some of the specific opportunities created by modern light technologies. Chu, for instance, spoke of how solar-power technologies are becoming increasingly competitive with traditional sources of energy based on fossil fuels. “I see the harnessing of light’s energy to be something that would give us clean energy, but also energy in the developing world that can leapfrog past transmission light grids,” he told me.
In fact, the idea that light-based technologies can provide solutions to challenges in the developing world was one of the key themes on the second day of the event. One of the speakers I caught up with is Linda Wamune, Kenya’s country director for an organization called SunnyMoney, which is promoting and distributing LED-based solar lanterns. These devices are particularly useful in rural locations that are not currently connected to electricity grids. At present, many people in the developing world use kerosene lamps, which are expensive and dangerous because of the fumes they produce.
See what Wamune and many others have to say about the role of light in their professional lives in next week’s video. In the meantime, don’t forget to check out our free-to-read digital collection of 10 of the best Physics World features related to the science and technology of light, spanning everything from the physics of rainbows to a new type of glasses that could bring improved vision to millions.
Trackback: Physics Viewpoint | Personal views on the International Year of Light
Simplifying light in schools
India is a very densely populated country and hence frequently teachers have to use simple and low-cost methods for performing experiments in schools. In a sense, it is boon for innovating simple alternative methods. Let me give a brief description of two simple experiments, which I developed in 1978 and 1987. I hope following description will inspire teachers, – especially Indians, Asians and even Africans.
1) Determining the refractive index of a prism: In the conventional method, the angle of minimum deviation is determined graphically and so student has pay lot of time in drawing ray diagrams for getting the set of angles of incidence and deviation. So after the first year of teaching, I focused on determining the angle of minimum deviation, without graph and without spectrometer and develop a new method, requiring reduced time but without costing the accuracy. For that, I had to derive a new equation for the angle of deviation, using just school geometry. See: The Physics Teacher (of the American Association of Physics Teachers) November 1978, p. 560.
2) Determining the angle of minimum deviation, without graph and without spectrometer: The graphical determination of angle of minimum deviation has some uncertainty because one has to draw a tangent to the curve of graph. So I wanted to develop a new method, which does not require drawing graph and which does not require a spectrometer because it is a costly instrument. I could eventually modify my 1978 equation in 1987. It enables one to find out the angle of minimum deviation without graph and without spectrometer. It requires only one reading and an average student can determine the angle of minimum is just 5 minutes, by using paper, pins, protractor, pencil. See: Bulletin of the I.A.P.T. – August 1987.
3) Derivation of the Prism Formula: The conventional way of deriving this equation is not appealing from the point of view of physics because one mathematical step appears like a trick. Therefore I developed an alternative derivation of the prism formula. See: Bulletin of the I.A.P.T., April 1988.
Motivating students to take up challenges in basic research: Over the years, a strong tradition has grown in our society – that is training students using “21-Expected Question”. But I train my students (though I retired 10 years ago) by giving them “21-Unexpected Questions” because life is full of such questions. Above three contributions are really useful for motivating students.