Science AMA Series: Stephen Hawking AMA Answers!

On July 27, reddit, WIRED, and Nokia brought us the first-ever AMA with Stephen Hawking with this note: At the time, we, the mods of /r/science, noted this: “This AMA will be run differently due to the constraints of Professor Hawking. The AMA will be in two parts, today we with gather questions. Please post your questions and vote on your favorite questions, from these questions Professor Hawking will select which ones he feels he can give answers to. Once the answers have been written, we, the mods, will cut and paste the answers into this AMA and post a link to the AMA in /r/science so that people can re-visit the AMA and read his answers in the proper context. The date for this is undecided, as it depends on several factors.” It’s now October, and many of you have been asking about the answers. We have them! This AMA has been a bit of an experiment, and the response from reddit was tremendous. Professor Hawking was overwhelmed by the interest, but has answered as many as he could with the important work he has been up to. If you’ve been paying attention, you will have seen what else Prof. Hawking has been working on for the last few months: In July, Musk, Wozniak and Hawking urge ban on warfare AI and autonomous weapons “The letter, presented at the International Joint Conference on Artificial Intelligence in Buenos Aires, Argentina, was signed by Tesla’s Elon Musk, Apple co-founder Steve Wozniak, Google DeepMind chief executive Demis Hassabis and professor Stephen Hawking along with 1,000 AI and robotics researchers.” And also in July: Stephen Hawking announces $100 million hunt for alien life “On Monday, famed physicist Stephen Hawking and Russian tycoon Yuri Milner held a news conference in London to announce their new project:injecting $100 million and a whole lot of brain power into the search for intelligent extraterrestrial life, an endeavor they’re calling Breakthrough Listen.” August 2015: Stephen Hawking says he has a way to escape from a black hole “he told an audience at a public lecture in Stockholm, Sweden, yesterday. He was speaking in advance of a scientific talk today at the Hawking Radiation Conference being held at the KTH Royal Institute of Technology in Stockholm.” Professor Hawking found the time to answer what he could, and we have those answers. With AMAs this popular there are never enough answers to go around, and in this particular case I expect users to understand the reasons. For simplicity and organizational purposes each questions and answer will be posted as top level comments to this post. Follow up questions and comment may be posted in response to each of these comments. (Other top level comments will be removed.)