May 16 is the International Day of Light, established by UNESCO in November 2017. It focuses on the role of light in science, culture and the arts, education and sustainable development, as well as in areas as diverse as medicine, communications and energy.
The holiday was preceded by the idea of holding the International Year of Light and Light-based Technologies, IYL2015, implemented at the initiative of UNESCO in 2015. The success of the action prompted a number of representatives of this organization to consider a resolution on the establishment of an annually celebrated holiday dedicated to the role of light in human life. That year, 147 countries held over 13,000 events dedicated to the role of light in science, culture, art, medicine, and everyday life.
Light plays a central role in human activities. At the most fundamental level, through photosynthesis, light is the source of life itself. The study of light has led to promising alternative energy sources, significant medical advances in technologies for diagnosing and treating diseases, the creation of high-speed Internet, and many other discoveries that have revolutionized society and shaped our understanding of the universe. These technologies have been developed over centuries of fundamental research into the properties of light, from Ibn al-Haytham's Kitab al-Manazir (The Book of Optics), published in 1015, to Einstein's work in the early 20th century that changed our perception of time and light.