UCL Mathematical & Physical Sciences


UCL celebrates UNESCO's International Day of Light

23 May 2018

UNESCO Day of Light 2


On 15th May, UCL Mullard Space Science Laboratory organised a secondary schools event to celebrate UNESCO's International Day of Light. The event was sponsored by Nature Communications as well as Nature, the international journal of science, and was attended by 240 year 7 and 8 students.

During the day students were able to listen to talks that discussed the chemistry of how light is made, the importance of light in the development of modern humans and how light is generated and used by animals. A series of hands-on activities were also run during the day by scientists, engineers and archaeologists from across UCL.

Professor Lucie Green (UCL Mullard Space Science Laboratory), one of the organisers, said, "We are passionate about working with our schools both locally and nationally. Everyone benefits from an open discussion about the latest research."

The International Day of Light aims to provide a continued appreciation of light and the role it plays in science, culture and art, education, and sustainable development, in fields as diverse as medicine, communications, and energy. The broad theme of light will allow many different sectors of society worldwide to participate in activities that demonstrates how science, technology, art and culture can help achieve the goals of UNESCO - education, equality, and peace.

UNESCO Day of Light 1

Professor Andrea Sella (UCL Chemistry) demonstrated how light from a candle can be split into its component parts using a diffraction grating, he compared that spectrum with one from a helium lamp to illustrate how spectroscopy has connected the world of the laboratory to the immensity of space; a discovery that transformed chemistry from a local to a universal science.

With ultraviolet lights Professor Sella illustrated the universality of fluorescence showing how chlorophyll fluoresces red (allowing for monitoring by satellites), tonic water fluoresces blue, and how one can write secret messages using that most reviled of inks, Marmite.

Emma, a year 7 school student said, "I really enjoyed going to UCL and I loved learning so much about light. One of my favourite parts of the day was during the first lecture when Andrea Sella showed us how ultraviolet light works by shining a UV light on tonic water, olive oil and even Marmite!"

Dr. Will Dunn (UCL Physics & Astronomy) led the hands-on demonstrations and said, "We wanted to show just how diverse our scientists and engineers are. Giving school students the opportunity to really interact with the people carrying out the research, and giving them the chance to have a go themselves, is a great way to have a lasting positive impact."

The event was supported by Dr. Mark Fuller (UCL Physics & Astronomy) who works to promote outreach activities that are committed to enhancing physics teaching and learning.



  • UCL Mullard Space Science Laboratory
  • UCL Physics & Astronomy
  • Professor Lucie Green's academic profile
  • Dr Will Dunn's academic profile
  • Professor Andrea Sella's academic profile
  • Nature Communications
  • Nature
  • UNESCO International Day of Light


Credit: Dr Mark Fuller (UCL Physics & Astronomy)