David Shillington is Associate Professor Applied Health Sciences, and Senior lecturer in Chemistry at UCOL. He knows a lot about Science. Here’s what he has to say about Sunlight…
2015 is the UN international year of light and light based technologies. It is a joint initiative between the United Nations Educational and Scientific and Cultural Organisation (UNESCO) and many scientific organisations around the world. It aims to raise global awareness of the social, economic and developmental role of light and optical technologies. Light is vital as a source of life and also is essential for many technologies which have revolutionised medicine and daily communications. These industries create jobs, generate economic growth and help us to address global issues such as sustainability and the energy challenges ahead. Our first experiences of light and colour occur through what we see in the natural world. Rainbows, sunsets, the blue sky, the Northern and Southern lights, the varied colours of flora and fauna are all ways we see how light manifests itself in nature.
Palmerston North is very fortunate, as it is soon to be the home of a newly developing exhibition called “Sunlight” This will open at the science museum at Te Manawa. One may wonder where such an exhibition could begin regarding the history of light? Well, very soon after the Big Bang, an important stage of the evolution of the universe occurred when the temperature was cool enough (about 4000 degrees Centigrade) for neutral atoms to form. Up until this time the numerous charged particles in existence prevented light from travelling very far. After the formation of atoms, light could travel immense distances and we can now observe microwave background radiation (a form of “light” that has been travelling for over 13 billion years).
Important to us, was the more recent formation (about 4.5 billion years ago) of a particular star we call the Sun and the material around it we call the Solar System. The Sun has shone over Earth ever since, initially allowing photosynthetic cynanobacteria to use sunlight to convert carbon dioxide and water into carbohydrates and oxygen. After producing vast quantities of oxygen, they then provided for oxygen-breathing life to evolve. Now the world depends on plants which use chlorophyll to achieve similar results and which help sustain the various life forms found on Earth.
When humans evolved very much more recently, they discovered many more sources of light starting with fire (camp fire light) and fuel burning lamps, advancing through to using electricity to “light up” incandescent lights, then progressing through to inventing fluorescent lighting and light emitting diode technologies. Branching out further, using wavelengths of radiation which are on either side of the visible radiation spectrum (shorter and longer in wavelength than visible light), society now uses electromagnetic radiation usefully in many forms. We are familiar with communication and entertainment through radio waves. Microwave technology not only allows us to cook food efficiently, the development and use of cellphones allows us to communicate and use the internet from fairly remote locations. X-rays, ultrasound and magnetic resonance imaging have allowed us to see inside ourselves and to make enormous medical advances in cancer treatment.
What an exciting field to develop an exhibition around! Te Manawa’s CEO Andy Lowe and his staff, with the support of its Science Society members, contracting personel and some generous sponsorships, have been hard at work to provide the citizens of Palmerston North with a thought provoking, scientific exhibition that will be worthy of sharing with other institutions nationally and internationally. That’s not bad for something home grown in our lovely Palmerston North.