After having pioneered the theory behind the existence of black holes nearly forty years ago, renowned physicist Stephen Hawking now says NASA can stop looking for the cosmic phenomenon. The concept of black holes has fascinated both traditional scientists and science-fiction writers and fans alike. They have been imagined as everything from an inescapable force that would eventually consume the universe, to potential gateways through time and space itself. For scientists such as Hawking, the key principle behind a black hole is that of the “event horizon,” a phenomenon Hawking says he no longer believes exists.
This is not to say that Hawking has discarded the concept of black holes entirely. He says, however, that the event horizon, as he originally conceived of it, does not exist. In his classic lecture Into a Black Hole, Hawking likens the event horizon to approaching a waterfall in a boat. The closer the boat gets to the edge, the more difficult it becomes to escape. Escape is still possible, though, until the edge is reached. Once the boat goes over the edge, there is no going back. That is the event horizon of a black hole, according to Hawking’s original theory.
It is this phenomenon that Hawking says no longer exists and space agencies such as NASA can cease their search for. Instead, he says something called an “apparent horizon” may exist. This new theory holds that instead of an inescapable threshold past which not even light can emerge from, black holes may instead simply hold light, matter, and information for a given period of time, after which it could escape and continue travelling through space. So while Stephen Hawking says NASA can end its search for black holes, it can look instead for these new “gray holes.”
Just as Hawking’s original theory was not definitive, so too is his new theory currently unprovable. He says to prove the apparent horizon would require a new conception of gravity that merges it with other forces of nature. A full understanding of the phenomenon he says “remains a mystery.” It is precisely these kind of mysteries that space agencies such as NASA were created to address, however.
There is much debate about the current status and importance of space exploration. In this age of government deficits and expanding budgets, funding for agencies such as NASA and their efforts to investigate phenomenon such as black holes, has become somewhat controversial. At the height of the Cold War, NASA composed nearly 4.5 percent of the entire federal budget. Currently, spending for NASA is less than one-half of one percent of the budget. This has forced NASA to rely on private companies for space related services and forced cuts to programs like those that would identify and explore phenomenon like black holes.
This concern has even emerged in popular culture. The upcoming film Interstellar will involve this struggling and downsized NASA attempting to mount an exploration of newly discovered space phenomenon in a near future scenario with the Earth facing a crisis. While few details of the plot are known, there is a similarity between black holes and the phenomenon that will be explored in the film.
Black holes are a phenomenon that has fascinated scientists and science-fiction fans alike for many years. Just as Stephen Hawking’s original work regarding them became the focus of much discussion and debate, his new theory will likely generate similarly enthusiastic discussion. According to Stephen Hawking, NASA can stop looking for black holes.
By Christopher V. Spencer