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Friday, Mar. 7, 2014
The Sky is fallingPosted Saturday, September 13, 2008, at 9:50 AM
Because of the popularity of late night radio, a lawsuit filed in Hawaii, and some rather prolific blogging, cutting edge physics has again made the headlines:
CNN September 12, 2008
A hopeful crush on the LHC
Posted: 12:15 PM ET
"It's not every week we power up a machine and wonder about the speculations, however unwarranted, that a black hole will swallow the planet. On Wednesday morning, everyone was either utterly fascinated or fearful as the Large Hadron Collider, a $10 billion machine more expensive and powerful than any of its predecessors, started up for the first time."
The world didn't end, but just to make sure we weren't playing with the proverbial fire, I contacted a physicist friend of mine to get his take on the matter (no pun intended). Here is what he said:
"As a physics teacher, I suppose I ought to be glad. I am. But it does remind me how those of us in the business of science education need to do a better job of reaching the public.
In any case, here is one opportunity. This week, at the European Organization for Nuclear research, an experiment began in the Large Hadron Collider (LHC). The LHC is
"a particle accelerator used by physicists to study the smallest known particles -- the fundamental building blocks of all things. It will revolutionize our understanding, from the minuscule world deep within atoms to the vastness of the Universe."
So says the LHC website. That is, the goal of the experiment is twofold. Researchers will test the so-called 'standard model' of the nature of matter while also testing differing versions of the 'Big Bang' theory which most physicists believe accurately describes the origin of the present universe. The experiment is really rather simple: two beams of protons or electrically charged lead atoms are fired at one another at a speed closer to that of light than in any previous such experiment. At these speeds and the corresponding high energy of the particles, current theory predicts black holes may be produced. A black hole is formed when matter is squeezed into so tight a space that even light can't escape the resulting gravity. These particular black holes would be tiny-really tiny. The largest theoretical BH that the collider could produce would be many powers of ten smaller than a proton… a particle which is itself about one hundred thousand times smaller than an atom. The best theory available predicts that such exotic objects would be unstable… so unstable that they would decay in less than a one hundred millionth of a billionth of a billionth of one second by shedding so-called 'Hawking radiation" named after Stephen Hawking, who first predicted it in the 1970's. Concern evidently started in the media when a German chemist published a non peer-reviewed paper (scientifically vetted) that suggested that such BH's might be stable after all. If so, such a tiny object could pass back and forth through the earth acquiring more and more matter, thus expanding to consume the earth. The paper was reviewed by well placed particle physics who found numerous inconsistencies and inaccuracies. In a nutshell: its baloney.
But ah, you say, suppose those things really are stable after all! What assurance can you give me that one or more produced by the LHC won't eat the earth and bring doomsday!
It turns out that the best reason not to worry is that if the LHC makes mini black holes, so do cosmic rays in the earth's atmosphere! In other words, they occur naturally. In fact, there are at least two observatories tasked on detecting black holes through their decay signatures in the earth's atmosphere. Expected observation rates could top more than 20 per year according to information from one of these observatories. So, either the LHC can't make little black holes to begin with, or else they are so common that doomsday would already have occurred even if they are dangerous. If they're real, the happen all the time. If not, there is no concern at all. We should however excited about the experimental results because of what they will tell us about our amazing cosmos and its origin."
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