Assessment of Producing Mini Black Holes

The construction of a machine for the physics experiment was completed at Brookhaven National Laboratory (BNL) at the beginning of November 1999. The machine is called the Relativistic Heavy Ion Collider (RHIC, pronounced "Rick"), and its purpose is to create the stuff that has not existed since the early universe (quark-gluon plasmas). An article on this machine and related physics has been published in the March 1999 issue of Scientific American [1]. Sending letters to the editors of this journal, some readers expressed worries about the possibility of catastrophic results by the production of unknown matter and miniature black holes. Two of the letters were printed in the July 1999 issue together with the reply from the physicist Frank Wilczek of the Institute for Advanced Study in Princeton, N. J. His conclusion was that a doomsday scenario was not plausible [2].

A committee of distinguished physicists convened by BNL Director John Marburger gave a more complete answer to this Sci-Fi like problem recently. The speculative disaster scenarios considered were:

• Creation of a black hole that would "eat" ordinary matter.
• Initiation of a transition to a new, more stable universe.
• Formation of a "strangelet" that would convert ordinary matter to a new form.

The committee concluded that there were no credible mechanisms for catastrophic scenarios at RHIC. A summary of the committee report can be viewed at a website [3]. BNL Director Marburger said [4], "Nature has been creating collisions of energies comparable to those at RHIC for billions of years, and there is no evidence of any kind of disaster related to those collisions. RHIC does not take us beyond the limits of natural phenomena. It brings a rare phenomenon into the view of our instruments so we can puzzle out its inner workings."

The fact that a comprehensive assessment has been made of the very speculative "disaster" is to be welcomed. However, we should worry about that the assessment of more probable danger is sometimes incomplete in a certain country.

1. M. Mukerjee, Sci. Amer. 280 (3), 42 (1999).
2. F. Wilczek, Sci. Amer. 281 (1), 5 (1999).
3. Brookhaven Natl. Lab., Committee Report on Speculative "Disaster Scenarios" at RHIC (1999).
4. Brookhaven Natl. Lab. News Release (Oct. 6, 1999).