The Large Hadron Collider, the largest and most expensive scientific instrument ever built in peacetime, begins operations on September 10 when a beam of high-speed protons begins shooting around the machine's 16 mile (27 -kilometer) circular tunnel beneath Geneva, Switzerland. When the protons collide with each other inside the machine, one thing that scientists are certain won't happen is the production of miniature black holes that gobble up nearby matter. A new study shows that the continuing existence of old stars in the sky is evidence that small black holes can't swallow the Earth.That is not to say that the new collider might not actually create mini-black holes as no one knows for sure what will emerge from the debris of the LHC collisions.
Black holes are thought to represent the ultimate state of compressed matter, with gravity so powerful that any bit of matter, and even light, would be sucked inexorably inwards with no chance for escape if it gets too close to the black hole's boundary.
That was the thinking about black holes before Stephen Hawking, the Cambridge University scientist, came forth with the idea that even black holes can lose energy. The density of energy inside a black hole is so huge that some of it can be converted into creating new particles, he said. If this conversion happens right at the edge of the black hole, Hawking argued, some of those new particles could escape, taking energy with them. In this way black holes can lose energy. They can "evaporate."
There is a rule in physics that says that the smaller the black hole, the quicker the evaporation. For an LHC-style black hole, estimated to be only a billionth of a billionth of a meter across (an atto-meter) the black hole would exist for a bit more than a few billion-billion-billionths of a second. It wouldn't be around long enough to swallow any nearby matter and would pose no danger to ordinary matter.
But what if Hawking is wrong? What if some black holes don't evaporate, but go on eating matter? What if scientists create some small, long-lasting black holes in Geneva, and they get loose? This possibility is addressed in a new report in the journal Physical Review D. (Journalists can obtain the text at www.aip.org/physnews/select ).
I am glad that Hawkings was right because if he was wrong we would not have had to worry about weather or not the Bible is right.
