Most physicists foolhardy enough to write a paper claiming that "there are no black holes" -- at least not in the sense we usually imagine -- would probably be dismissed as cranks. But when the call to redefine these cosmic crunchers comes from Stephen Hawking, it's worth taking notice. In a paper posted online, the physicist, based at the University of Cambridge, UK, and one of the creators of modern black-hole theory, does away with the notion of an event horizon, the invisible boundary thought to shroud every black hole, beyond which nothing, not even light, can escape.
In its stead, Hawking's radical proposal is a much more benign "apparent horizon", which only temporarily holds matter and energy prisoner before eventually releasing them, albeit in a more garbled form.
Steven Hawking came up with a simple and clever way of seeing if time travel is possible. On June 28, 2009, he threw a party for time travellers from the future...but didn't advertise it until after the party was already over.
In an effort to improve the chances of the party invite being noticed by future generations, Peter Dean, working with approval from Hawking, has made this gorgeous hand-printed poster of the party invitation:
I have been fortunate in the director of the film, Errol Morris. He is a man of integrity, with a feeling for the issues. It would have been all too easy to have someone who would have concentrated on the more sensational aspects of my private life, and my medical condition, and who would have treated the science in a superficial way. A friend of mine, who has had several television programmes based on his work, was envious of how the scientific ideas came through on the film.
Claudia Dreifus of the NY Times scores a rare interview with Stephen Hawking. The ten questions were sent to him in advance and then he met with Dreifus in person to play his answers for her.
Q. Given all you've experienced, what words would you offer someone who has been diagnosed with a serious illness, perhaps A.L.S.?
A. My advice to other disabled people would be, concentrate on things your disability doesn't prevent you doing well, and don't regret the things it interferes with. Don't be disabled in spirit, as well as physically.
Audio clips of some of his answers are available in the article's sidebar. Interestingly, despite the advances in text-to-speech audio and upgrades to his writing hardware & software, Hawking's voice remains the same.
In The Grand Design we explain why, according to quantum theory, the cosmos does not have just a single existence, or history, but rather that every possible history of the universe exists simultaneously. We question the conventional concept of reality, posing instead a "model-dependent" theory of reality. We discuss how the laws of our particular universe are extraordinarily finely tuned so as to allow for our existence, and show why quantum theory predicts the multiverse--the idea that ours is just one of many universes that appeared spontaneously out of nothing, each with different laws of nature. And we assess M-Theory, an explanation of the laws governing the multiverse, and the only viable candidate for a complete "theory of everything."
If we want to travel into the future, we just need to go fast. Really fast. And I think the only way we're ever likely to do that is by going into space. The fastest manned vehicle in history was Apollo 10. It reached 25,000mph. But to travel in time we'll have to go more than 2,000 times faster. And to do that we'd need a much bigger ship, a truly enormous machine. The ship would have to be big enough to carry a huge amount of fuel, enough to accelerate it to nearly the speed of light. Getting to just beneath the cosmic speed limit would require six whole years at full power.
Description of attending an amazing talk by Stephen Hawking. "In the beginning there's a long pause. Really long. The applause dies down and then... crickets. For thirty seconds... a minute... two minutes. Then suddenly, Hawking's synthesized voice: 'Can you hear me?' The climactic scenes of blockbuster movies are not as thrilling."