In its 68th Session, the United Nations General Assembly declared 2015 as International Year of Light and Light Related Techniques (IYL 2015). IYL 2015 is the culmination of years of negotiation by various stakeholders like the scientific community, educational institutes, non-profit organisations and of course Unesco. IYL 2015 will be administered by an international steering committee in collaboration with the International Basic Science Program of Unesco and the Abdus Salam International Center for Theoretical Physics, Trieste, Italy. The aim of IYL 2015 is to create awareness of Light Sciences and their Application, and to bring into attention light based techniques so essential to meet the global challenges of energy, education, agricultural, health and medicine as well as communication.
Many scientists believe the 21st century will depend on photonics as much as the 20th century depended on electronics. So what is photonics? Simply put, photonics is the science of generating, detecting and manipulating photons or light particles. Photon technology supports smart phones, laptops and internet. No departmental store can do without it now. CDs require very precise light known as Laser. Light is a key ingredient in many large facilities, including the Synchrotron and Free Electron Lasers (FEL). It is indispensible for both pure and applied research.
Photon technologies provide tools for doctors and surgeons in optometry and other vision related sciences. They are also used in varied medical diagnostic purposes in ways that were unthinkable a few years back. The interplay of light in nature manifests most beautifully in sunrise, sunset, rainbow, the blue of ocean and sky, and in plants and animals. Satellites and telescopes high in orbit have brought us incredible pictures of the cosmos from the nearest planets to the most distant galaxies, and all of these because of light technology. Light is of course at the origin of life -- through photosynthesis.
Growth in the photonics industry has been phenomenal over the past decade. With current global market of more than $300 billion it is expected to grow to $600 billion by 2020. A single significant use of sunlight is its conversion to solar electricity. Like geothermal, wind and tidal energy sources the solar power plant is an environment friendly, non-pollutant, clean energy source. Solar energy is also not prone to international fuel price fluctuations and is practically inexhaustible. With decreasing cost to generate solar electricity it is increasingly becoming competitive with other forms of electricity generation.
Driving through the Mojave Desert (Nevada-California) on the way to Las Vegas on July 6, 2014, we were struck by the barren, sun scorched, hilly and rugged terrain of the desert. This area receives almost twice the solar radiation than any other state in the USA -- a fact that has been fully exploited by the US Department of Energy. There are nine solar power plants in the Mojave Desert with a combined capacity of 354 megawatts (MW). However, the most impressive and by far the largest solar thermal power facility is the newly built 392 MW Ivanpah Solar Power Facility located 64 km southwest of Las Vegas. It became operational in February 2014 and deploys 347,000 heliostat (sun tracking) mirrors focusing solar energy on boiler located on centralised solar power towers. The Ivanpah Solar Power Facility is just off interstate highway 15 on the Nevada-California border in the Mojave Desert.
According to Asian Development Bank Report 2013, more than half of Bangladesh's population has no access to electricity. To provide clean energy to more people the government of Bangladesh signed a deal with the World Bank to help install 480,000 solar home systems. The International Renewable Energy Agency (IRENA), in its 2014 report, shows that Bangladesh is currently installing 70,000 solar panels a month. The quantum jump from 25,000 to 2.8 million installed solar systems in ten years is a great success story in itself.
The year 2015 also marks the 1,000th anniversary of the publication of the seven volume treatise on optics by the Arab scientist Ibn Al-Haytam. Born in present day Iraq, Al-Hasan Ibn Al-Haytam was a brilliant scientist who made important contributions in the field of vision and light. To acknowledge the contributions made by Muslim scholars, Unesco plans on holding exhibitions and seminars entitled “The Islamic Golden Age of Science for the Knowledge Based Society” on September 14, 2015.
Planned anniversaries to be highlighted also include: (i) 1015: Work on Optics by Al-Haytam (ii) 1815: The notion of light as a wave propounded by Fresnel (iii) 1865: The electromagnetic theory of light propagation proposed by Maxwell (iv) 1915: Einstein's Theory of Photo Electric Effect in 1905 and the General Theory of Relativity that shows how light was at the centre of the structure of space and time (v) 1965: Discovery of the Cosmic Microwave Background by Penzias and Wilson that paved the path of the origin of the universe, and Charles Kao's successful transmission of light through fibers for optical communication.
To celebrate IYL 2015, countries around the world have arranged seminars, discussions, photo exhibitions etc. Some of these are: Discovering Light, in Portugal; Light and Shadows, in Germany; Hikari -- the World of Light, in Japan; Photo Selfie, in USA; Light and Architecture, in China; Light Beyond the Bulb, in UK; Nano Days, in Egypt; Shoobh Art Competition -- 2015, Theme Light, in India; Light on Art Work, in Canada; Visual Art Work, in Mexico, etc.
In announcing IYL 2015 the United Nations has recognised the importance of Light Sciences and its Application. For over 1.5 billion people around the globe night time is either complete or partial darkness; the IYL will also promote ways to mitigate such sufferings.
The writer is Professor of Physics, Jahangirnagar University, Fellow of the Royal Astronomical Society (UK) and Fellow of the Bangladesh Physical Society.