1. World Science Festival
World Science Festival is held in New York and it first took place from may 22 to June 1 in 2008. The festival was founded by Brian Greene, a professor at Columbian university and author of several science books, and Tracy Day, an award-winning journalist. He is now a Chairman of the World Science Festival, while she is the CEO. The first World Science Festival was comprised of 46 events and a street fair. There was also a World Science Summit on the first day of the festival. Many speakers were Nobel Prize winners and there were more than 120,000 people in the audience. According to their website, the festival now has over 1.5 million visitors collectively, which makes it the first on our list of 6 biggest science festivals around the world. The World Science Festival includes events such as discussions, interactive explorations, debates as well as musical performances and many other. Among past participants are some amazing names such as Stephen Hawking.