Light-based technologies: sustainable solutions for the future

Over a thousand participants came to UNESCO on 19-20 January 2015 to learn about the many ways in which light is making a difference in our daily lives and exchange ideas on the solutions light-based technologies can provide to current global challenges. The 2-day opening ceremony of the International Year of Light (IYL2015) gathered leading scientists, including 5 Nobel Prize winners, as well as decision makers, NGO representatives and industry representatives to discuss all aspects of light, from the quantum to improved street lighting or affordable glasses.

The study of light has led to applications that have shaped our current information society. Fiber-optic communications enable the internet we use today. Lasers can encode hundreds of terabytes of data to store an ever growing knowledge base. Light-based technologies are helping us explore space with telescopes equipped with sensors that collect data from the ultraviolet to the infrared range of the spectrum, and even map our Universe in its infancy by capturing the cosmic microwave background – the relic radiation from the Big Bang. Remote sensing from satellites is also helping us to better understand our planet, predict the weather, and monitor and manage pollution.

Closer to home, the great strides made in medical imagery save lives: today diagnoses are made using non-intrusive, below the skin 3D imagery, and light-based therapies can target cancer cells selectively.

The retina of your eye consists of many interconnected layers of nerve cells, some of which are sensitive to light. © Wei Li, National Eye Institute, National Institutes of Health

Practical applications that are available today can make the most difference in remote areas and developing countries, where millions live with no access to electricity. Something as simple as a source of light after dark can help a family out of poverty: children can study longer and learn more, parents can also remain active after dark. Sub-Saharan Africa, were 65% of the population is off the grid, also has the greatest exposure to sunlight in the world. Solar lighting (lamps that recharge during the day with solar energy) has proved to be a good alternative to kerosene lamps. Not only is kerosene more expensive in the long run and less efficient, as such lamps are too dim to read by, but it is also hazardous and the fumes are toxic. On a slightly larger scale, solar panels are providing power for community refrigerators to preserve medicine, for cellphones and other appliances, thus improving living conditions in villages.

Light provides efficient, renewable alternatives that can help us mitigate climate change and meet energy demands, by both providing energy and diminishing energy consumption. According to the United Nations Environment Programme (UNEP), improved, efficient lighting could cut energy consumption for lighting by 50% and CO2 emissions equivalent to that of Germany could be avoided each year. Should we fail the transition to efficient lighting, energy consumption would grow by one third.

Installation "Light is Here" by Finnish artist Kari Kola, intstalled by Valoparta Ltd.© UNESCO/Nora Houguenade

Light has always powered us, by turning CO2 and water into sugar and oxygen through photosynthesis, thus creating the fuel and oxygen we need. Now, engineers are making progress on artificial photosynthesis to generate fuel from sunlight. New materials are being developed to harness solar energy on urban surfaces. Such innovations could change the energy game completely.

Only a century ago, we could not imagine how far light would take us: what applications could be developed by studying its properties. The 21st century will depend as much on photonics as the 20th century depended on electronics. Phototonics, the science of generating and controlling particles of light (photons) underpins technologies of daily life, from smartphones to the Internet, to medical instruments, to lighting technology. These technologies were developed through centuries of fundamental research on the properties of light – starting with Ibn Al-Haytham’s seminal work, Kitab al-Manazir (Book of Optics), published in 1015 and including Einstein’s work at the beginning of the 20th century, which changed the way we think about time and light.

Today the search continues, and new facilities are being built to expand our knowledge, such as the Synchrotron-light for Experimental Science and Applications in the Middle East (SESAME). Modelled institutionally on CERN – with different scientific goals – and set up under the auspices of UNESCO, SESAME is an intergovernmental facility built in Jordan. When it starts operations in 2016, SESAME will provide a vast scientific potential for scientists from the Middle East and neighbouring countries, enabling them to determine the structure of complex biologically active molecules and viruses in order to improve medical remedies; to get insight into the interior and the three-dimensional micro-structure of objects such as materials of primary importance for high technologies, cultural heritage and archaeology; or to investigate magnetisation processes, which are highly relevant for magnetic data storage, to cite just a few examples. Those we can imagine today.

One of the five Nobel Plenary Lecture that took place during the opening of the IYL2015.© UNESCO/Nora Houguenade

About the Year    
The International Year of Light and Light-based Technologies (IYL2015) has been the initiative of a consortium of scientific bodies together with UNESCO’s International Basic Sciences Programme. The Consortium brings together many different stakeholders including scientific societies and unions, educational institutions, technology platforms, non-profit organizations and partners form the private sector. The main objective of the Year, which is led by UNESCO, is to raise global awareness of how light-based technologies can provide solutions to the global challenges of sustainable development.

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American violinist Joshua Bell performs "Einstein's Light" during the opening of the International Year of Light 2015. © UNESCO/Nora Houguenade