International Day of Light 2023

16 May marks the International Day of Light, proclaimed by UNESCO in 2015 for 16 May, the anniversary of the creation of the world's first laser, short for Light Amplification by Stimulated Emission of Radiation, by physicist T.H. Maiman in 1960.

Light plays a central role in our lives. Like water or food, light is a basic necessity. Without light, there would be no life as we know it; in fact, through photosynthesis, light is at the origin of life itself. The whole world benefits from advances in light science and its applications. Light-based technology has a wide-ranging impact in many areas, from medicine to food, communications and energy, and therefore it has an undeniable capacity to improve and revolutionise the quality of our lives.

These technologies have been developed by centuries of research into the properties of light, from Ibn Al-Haytham's seminal work, the Kitab al-Manazir (Book of Optics), published in 1015, to Einstein's studies in the early 20th century, which changed the way we think about time and light.

This day was established to commemorate the importance of light in the development of the human species, since we rely on light to see the world around us and, a little more broadly, the universe. By studying light, we have also succeeded in developing instruments such as microscopes, X-ray machines, telescopes, cameras, television screens, light bulbs and lasers.