beijing british theoretical physicist stephen hawk chinese microblog weibo account praise lead singer china popular boy band ask life beyond earth wang junkai leader singer wildly popular tfboys post video weibo account friday ask author brief history time humanity prepare interstellar migration years come hawk recently warn human race must evacuate earth 600 years soar energy consumption turn planet ball fire early month hawk make video appearance science summit organize tencent hold plead investors support idea travel close star outside solar system hope find inhabitable planet 75-year old physicist say video post weibo account wang ask excellent question give insight chinese millennnials curiosities regard future wang two band mat 30 million followers twitter-like weibo microblog account own weibo corp weibo china big social media platform 200 million active users hawk open weibo account last year 4.3 million followers british prime minister theresa may 900,000 inherit account david cameron stephen hawk laud chinese pop star space migration question