Big Bang in a Test Tube?Mar/00
Physicists at the CERN 33 TeV ion beam accelerator say that they have created temperatures corresponding to conditions that existed microseconds after the big bang. In so doing they have generated the long sought quark-gluon plasma in which quarks are "free". What often strikes me about announcements like this is that I spend a lot of time telling people what wasn't announced or calming fears about what it means. In this case there is no claim to have made a mini big bang, rather that temperatures were reached corresponding to 10 microseconds after the big bang. This is somewhat like the difference between making a "black hole" and making something which is black. Having one property in common doesn't mean they are the same thing. Fears that such experiments will spark something uncontainable which will destroy us... are unfounded. And speaking of black holes, this is another source of fears concerning particle accelerators. Stories in the press often make comparisons between a particular experiment and the density of a black hole. This leads some to fear that we will accidently create a small black hole which would then devour the earth in minutes. Similarly, a piece of stable strange matter that we might create has been theorized to convert regular matter it touches into strange matter and bring the world to a sudden inglorious end. In these latter scenarios particle physicists play modern Dr. Frankenstein's whose experiments will have consequences beyond their control. What is worth remembering is that for billions of years the earth has been getting bombarded with cosmic rays known to have energies up to 3*1020 eV. This is 100 billion times more powerful than the strongest accerators on earth, so history shows that we will be safe for quite some time to come. You might still be worried that though much higher energy particles have been bombarding the earth, they have not been hitting under the very particular conditions generated in high energy physics laboratories. To see that possible disaster scenarios have taken serious consideration and haven't just been brushed aside, you can read through the Committee Report on Speculative "Disaster Scenarios" at RHIC (RHIC = "Relativistic Heavy Ion Collider"). |