Science Rendezvous event held at campus of University of British Columbia in Vancouver

Children watch an experiment of a test tube disappearing inside a jar of liquid because of the light refraction during the Science Rendezvous event at the campus of University of British Columbia in Vancouver, Canada, May 11, 2019. With over 300 events across 30 cities, the Science Rendezvous is an annual festival held across Canada showcasing the art in science. (Xinhua/Liang Sen)