Thought leaders from industry, academia, government, and beyond will come together for the fourth annual International Day of Light (IDL) on May 16. A robust global itinerary is planned, as is a dedicated campaign — “Trust Science” — to promote societal awareness in the need to trust science. The campaign will begin May 16. After IDL fostered celebrations in 69 countries and reached an audience of more 750,000 last year, IDL 2021 will again feature celebrations from around the world aimed at the promotion of education, dialogue on research developments, and profiles of “Light Alumni” — volunteers who have contributed to the growth of the IDL. Worldwide Participation Events in 50 countries, representing six continents (as well as multiple coordinated worldwide events), will spotlight outreach and education opportunities. Digital programs such as the Australasian Dark Sky Alliances’ presentation of the “Your Light Rights” webinar and “The Future of Light” webinar series will engage citizens on responsible stewardship of light, and research into light-based technologies that will change the way people live, respectively. In a correspondence with Photonics Media, IDL 2021 co-chair Joe Niemela said campaigns such as these that emanate from light-based technologies align with U.N. sustainable development goals. “The UNESCO IDL helps to raise awareness of the many ways in which light sciences and associated technologies can help improve the quality of life in communities around the world, from the basic sciences to areas of concern in low-income countries in line with the U.N. sustainable development goals,” Niemela said. Energy-efficient lighting technologies for communities off the grid, photodynamic therapy for cancer treatments, and remote sensing applications for agriculture, food safety, and security are among the technologies Niemela identified. “In urban environments, tunable digital lighting systems offer a more productive environment in offices and classrooms, lidar or other optical techniques contribute to self-driving cars, and much more,” Niemela said. Transformative technologies and applications, such as quantum devices, nanofabrication, and lasers for medicine will also be featured. ChemFusion, a nonprofit organization of young undergraduate chemists of Bangladesh, will celebrate the IDL with an open lecture titled “Building Custom Quantum Machines Using Light Matter Interactions” delivered by Sambit Banerjee, a graduate student in Purdue University’s Department of Physics and Astronomy. Nanofabrication of Photonics Online Meetup (nanofabPOM) of Belgium will kick off a three-day conference on May 16 to facilitate the exchange of experience and know-how for the nanofabrication community. The conference will also include a career development panel discussion. The IDL will also mark the conclusion of currently ongoing events. The Lithuanian Laser Association is sharing an informational online event that explores the abilities of laser-based technology to diagnose diseases at the earliest stage and contribute to other biophotonics and medical applications. From Algeria to Vietnam, more than 100 nations will also come together as “National Nodes” to organize localized campaigns, activities, and events. Industry-acclaimed researchers, from institutions that include the Center for Optical Fibre Technology (Singapore), the Optical Society of India, the Brazilian Society for the Advancement of Science, and global organizations SPIE and OSA, are among those participating. The IDL will also highlight the “LIGHT WINDOWS” initiative that began in December 2020, which has connected artists and closed venues into public space in nearly 20 countries (and Antarctica) with over 90 distinct projects. In an event from May 14-16, people are invited to create installations to light up their windows in a celebration of creativity and connection. Featured Speakers More than 15 volunteer speakers from all reaches of the optics and photonics communities are supporting IDL 2021. As dates and times are not assigned to speakers, each is available to present at events throughout the year, on topics that range from the history of optics to scientific publishing, to ultrafast science and technology. Speakers include Roberta Ramponi, former president of the European Optical Society; Andrew Forbes, 2015 National Science and Technology Forum Photonics award winner; and Rachel Won, international editor of Nature Photonics. IDL 2021 Steering Committee chairs John Dudley and Niemela are also available to speak. Dudley, 2020 winner of the R.W. Wood Prize of The Optical Society and a professor of physics at the University Bourgogne Franche-Comté, and Niemela, 2016 recipient of the American Physical Society’s Dwight Nicholson Medal for Outreach recipient from the Abdus Salam International Centre for Theoretical Physics (ICTP), will lecture on topics that include societal implications of science, science education, advocacy, and science in developing countries. Trust Science The “Trust Science” campaign is set to kick off on May 16, with support from Nobel laureates, science and industry leaders, and educators worldwide. IDL participants and members of the public are encouraged to pledge their support and help spread the message that science is vital for the future of society. “As we raise awareness about the benefits of light-based technologies, we get a good sense of the vast and impressive breadth of applications that truly can affect people’s lives, from myriad applications of the laser to new technologies resulting from the blue LED,” Niemela told Photonics Media. “More than that, we also see entrepreneurs around the world who assess local needs and find or create new markets. Much of that is based on trust in the science of light.” This year, Niemela said, support for the Trust Science campaign has helped spread that type of awareness to an increasingly global audience. The Trust Science pledge states, “Trust in evidence-based, scientific facts is essential for providing sustainable solutions to today’s challenges. By adding my name to this declaration and pledge, I recognize the key role that scientific research and discovery plays in improving quality of life for all.” Together with the International Day of Light Steering Committee, organizers of the Trust Science pledge are the IEEE Photonics Society; SPIE, the international society for optics and photonics; and The Optical Society (OSA). How to Participate The International Day of Light on Sunday, May 16, is open to all, with registered events planned around the world. Complete information on this year’s program, information on volunteer speakers, initiatives, and the Trust Science campaign can be found at www.lightday.org, with additional information on Photonic Media’s website.