The Cambridge Science Festival will host Borealis — a free light-and-sound installation simulating the magic of the Northern Lights — at the Kendall/MIT Open Space in Kendall Square in Cambridge 8PM-11PM on the nights of October 6-9. The public is invited to come and go, move around, and enjoy its constantly changing aurora. The works’ creator, Dan Acher, is an international artivist based in Switzerland, an Ashoka Fellow and the founder of Happy City Lab.