A staff member of auctioneer Christie's holds a book titled "A Brief History of Time" written by Stephen Hawking during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)

A staff member of auctioneer Christie's shows Stephen Hawking's wheelchair during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)

A staff member of auctioneer Christie's shows a bomber jacket worn by Stephen Hawking during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)

A staff member of auctioneer Christie's shows a book titled "A Brief History of Time" written by Stephen Hawking during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)

A staff member of auctioneer Christie's shows Stephen Hawking's wheelchair during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)

A copy of Stephen Hawking's Cambridge University Ph.D. thesis is seen during a photocall for an online auction in London, Britain, on Oct. 30, 2018. An online sale of 22 items from the late physicist Stephen Hawking by auctioneer Christie's will open for bids on Oct. 31. The auction will include some of Hawking's complex scientific papers, one of his iconic wheelchairs and a script from the famous TV comedy show "The Simpsons." (Xinhua/Ray Tang)