Stephen Hawking gets some answers to save the world

Stephen Hawking, popularly considered as the most intellectual physicist of our time, asked a simple but profound question on Yahoo! Answers on July 5^th: “How can the human race survive the next hundred years?” (Yahoo! staff added: This is the real Stephen Hawking!) After 5 days, he gets more than 20,000 answers. However, not too many of the answers mean too much. He might be disappointed his opinion of colonizing the space is not widely mentioned. Sounds like we do have problem to survive.