Day of Light
The International Day of Light celebrates the role light plays in science, culture and art, education and sustainable development. Light continues to propel a range of diverse fields, such as medicine, communications and energy. The celebration aims to allow many different sectors of society, worldwide, to participate in activities that demonstrates how science, technology, art and culture can help achieve the goal of building foundations for a peaceful society.
The International Year of Light and Light-based Technologies 2015 (IYL 2015) was a United Nations observance that raised global awareness of the achievements of light science and its applications, and their importance to humankind. Under the leadership of UNESCO, more than 13,000 activities took place in 147 countries to reach an audience estimated at over 100 million.
After the success of the International Year of Light, it was clear that the proclamation of an International Day of Light will provide an enduring follow-up to the International Year of Light in raising the profile of science and technology, stimulating education and improving the quality of life worldwide.
Why 16th May?
Theodore H. Maiman was an American engineer, physicist and inventor born in Los Angeles, California in 1927; the son of electrical engineer and inventor Abraham “Abe” Maiman. From an early age he helped his father with experimentation in a home electronics laboratory and soon began to earn money repairing electrical devices and radios. Maiman’s academic career naturally flourished; with a degree in Engineering Physics, PhD in Physics and doctoral thesis on Experimental Physics. On this day (16th May) in 1960, Maiman successfully demonstrated a solid-state pink ruby laser. The world’s first laser device able to emit coherent light, with rays all the same wavelength and fully in phase.
On June 22 of that year, Maiman sent a paper to the Physical Review Letters about his achievement, but received a letter of rejection stating that the publisher was no longer interested in maser related papers. Next, he sent a short version of his paper to the British journal “Nature”. Consequently, the first scientific report about this historic invention appeared on August 6, 1960 not in the USA but in Great Britain. The paper was titled “Stimulated Optical Radiation in Ruby” (Nature, 1960, v.187, P.493).
Science & Technology
Light is key to our understanding of science and the development of technology. For thousands of years, the study of light and its properties has revolutionised every aspect of science and has involved all the major figureheads of scientific discovery. From Ibn Al Haytham, a medieval mathematician, astronomer, and physicist who lived in, what is now present-day Iraq and commonly referred to as “the father of modern optics”; to Galileo, Newton and Einstein. Inspiration often directly cited in papers, or as anecdotal influences from the individual themselves, spans scientific works throughout history.
The electromagnetic spectrum is vast; ranging from radio waves at one end, to gamma rays at the other and all wavelengths in-between; they have provided insights equally as wide, including the origin of the Universe and technologies that have shaped our society. For instance, advanced research in areas such as nanophotonics, quantum optics and ultrafast science are inspiring new fundamental discoveries and opening new scientific frontiers. Light-based technologies and photonics directly respond to the needs of humankind by providing access to information, promoting sustainable development and increasing well-being.
Photonics-enabled industries are also major economic drivers, and the many applications of photonics have transformed society through improved medicine, communications, and energy production. Photonics is ubiquitous in our daily lives. You do not have to look very far to reveal how these technologies have influenced and greatly improved our way of living. The smartphones in our pockets and fibre optic communications via the Internet are evidence of this. Photonics, coupled with other burgeoning developments, such as Quantum Computing is poised to become the key enabling technology of the future.
Call for visuals: Share your vision of light and quantum science
To celebrate the International Year of Quantum Science and Technology (IYQ) and the International Day of Light, UNESCO and partners are launching Quantum light: A visual odyssey, a global call for visual works inspired by the intersection of light and quantum science. Selected submissions will be showcased on UNESCO’s website.
Deadline for submission: 16 July 2025
- Call opens: 16 May 2025 (International Day of Light)
- Submission deadline: 16 July 2025
- Public voting: August 2025
- Publication of winners: October 2025
See UNESCO website for terms and entry requirements.
