Slashdot reader DevNull127 writes: Google marked what would've been Stephen Hawking's 80th birthday with a very special Doodlean animated video in which the voice of Stephen Hawking speaks again, generated and used with the approval of the Hawking estate. "My expectations were reduced to zero at 21. Everything since then has been a bonus," Hawking says in the video. "Although I cannot move and I have to speak through a computer, in my mind I am free. I have spent my life travelling across the universe, inside my mind." In the video tribute, Stephen Hawking passes through a black hole. "We are very very small," he says. "But we are profoundly capable of very very big things. "There should be no boundaries to human endeavor. However bad life may seem. While there is life, there is hope. Be brave, be curious, be determined, overcome the odds. It can be done." "From colliding black holes to the Big Bang, his theories on the origins and mechanics of the universe revolutionized modern physics," explains the Google Doodles page, "while his best-selling books made the field widely accessible to millions of readers worldwide." And Google's Arts and Culture blog shares a longer look at Stephen Hawking's life, including a 1979 photo of young Hawking at the Department of Applied Mathematics and Theoretical Physics at Cambridge University. "Because of Stephen Hawking's work, the radiation emitted by black holes is now called Hawking Radiation," the biography says at one point, also remembering Hawking's best-selling book A Brief History of Time: From the Big Bang to Black Holes. But they also share some more personal memories:In 1990, with lifelong friend, the physicist Kip Thorne, Stephen approached the controversial notion of whether time travel is allowed by the laws of physics. To explore this hypothesis Stephen planned a party for time travellers. He wrote invitations, set a date, time and venue and provided precise GPS coordinates. Stephen did not send out the invitations until after the party date was over. That way, only those who could genuinely travel back in time would know of it and be able to attend. On the due day Stephen sat politely and waited. But no-one came. And that was the point. "I have experimental evidence that time travel is not possible", he said afterwards. And the champagne went back on ice.... The biography closes with this quote from Stephen Hawking. "Remember to look up at the stars, and not down at your feet. Try to make sense of what you see and wonder about what makes the universe. "Be curious, and however difficult life may seem there is always something you can do and succeed at; it matters that you don't just give up."Read more of this story at Slashdot. Click here to read full news..