A child touches a static electricity ball at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)

Visitors read information on the big bang and red shift of the universe at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)

A staff member gives a brief introduction of magnetic levitation train to visitors at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)

Visitors view a wind-power generation system at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)

People experience static electricity at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)

Parents play a game with their child at Guangdong Science Center during the opening of the 2016 Guangzhou Science and Technology Week in Guangzhou, capital of south China's Guangdong Province, May 15, 2016. A series of science activities will be held on the week-long event in Guangzhou. (Xinhua/Wang Dongzhen)