Today the students undertook their first competitive task of the week – the experimental examination that was ratified in Monday’s international board meeting. The practical examination was based around two applications of diffraction.
|"Photo 51" (Source 1)|
The first application was inspired by the work of noted British scientist Rosalind Franklin. Franklin oversaw the use of X-ray diffraction to investigate the structural properties of DNA and the findings, shown here through the famous image “Photo 51”, were the basis that led Crick and Watson to discover its characteristic double helix shape. In the examination the students modelled this approach by determining parameters of two helical samples (a small, thin spring and a double helix cross-section), using diffraction of visible light from a laser source.
|Diffraction of visible light (Source 2)|
The second application used a phenomenon where a diffraction pattern can be obtained from waves on the surface of a liquid. In the second experiment students used a loudspeaker attached to a plastic plate to set up regular waves on sample of water and then, by again diffracting visible light from a laser source, were able to determine the surface tension and viscosity of the water in the sample.
|Monsoon season in Mumbai|
Whilst the students were sitting their experimental examination, the team leaders, observers and visitors were treated to a tour of South Mumbai, which included notable sights including the Gateway of India and the University of Mumbai, and also included a monsoon season downpour. It felt quite like being back in the UK with the torrential rain, although admittedly with considerably higher humidity. Following this, we the visited the Chhatrapati Shivaji Maharaj Vastu Museum, which contains over 50,000 exhibits on art, archaeology and natural history relevant to the region, such as artefacts from the Indus Valley civilisation.
Source 1: www.wikipedia.com (Photo 51)
Source 2: www.flickr.com (Dragonlasers)