Concern Over Creating Black Holes
Maria Williams writes to tell us about worry surrounding the impending startup of CERN's Large Hadron Collider. Some fear that the device, in creating mini black holes, could jeopardize Life As We Know It. While the tiny black holes should evaporate quickly — throwing off so-called Hawking radiation that can be detected — CERN software developer Ran Livneh reminds us that "Any physicist will tell you that there is no way to prove that generated black holes will decay." The LHC site assures us there's nothing to worry about. The flap is reminiscent of the time the Relativistic Heavy Ion Collider went live. The worry then was that "negative strangelets" could gobble up the world.
Primary cosmic rays impact the earth all the time, and these often have far higher energies than even our largest particle accelerators are capable of producing. For any experiment we attempt, we can be reasonably sure that colliding cosmic rays have already produced the same results, sometime within the past few billions years. If we could create massively destructive black holes through our particle accelerators, one would expect that stray cosmic rays would have already done so.
This type of fear occurred many times during the nuclear physics history, when higher and higher energies were explored. The answer against fears of unknown catastrophic effect has been that some cosmic rays are much more energetic than any artificially accelerated particles (10^21 eV for some cosmic rays in comparison to the feeble 10^12 eV in today accelerators such as LHC). For sure the Earth and the Sun did already receive zillons of cosmic rays without disappearing...