2015 was designated the International Year of Light and Light-based Technologies (IYL 2015) by the United Nations General Assembly. Various activities took place world-wide throughout the year to meet the U.N.’s proclamation toward recognizing the importance of “raising global awareness of how light-based technologies promote sustainable development and provide solutions to global challenges in energy, education, agriculture, and health.”

Opening ceremonies for the program and a two-day symposium with presentations by leading policy makers, scientists, and lighting designers took place on Jan. 19–20 at UNESCO’s Paris headquarters. Closing ceremonies commence today, Feb. 4, and run through Sat. Feb. 6 in Merida, Mexico. The presentations can be watched via live streaming on the IYL website.

Additionally, an interactive 3D globe projection at the closing ceremony will display all Twitter messages that use the hashtag #IYL2015. The location of the Tweet sender will be highlighted on the 3D globe as a virtual token of participation. To view the globe go to: http://projection.mi.hs-offenburg.de/view.php.

For an overview of IYL 2015 activities go to light2015.org.