A micro black hole, also called a quantum mechanical black hole and inevitably a mini black hole is simply a tiny black hole around which quantum mechanical effects play an important role.

The existence of micro black holes is purely hypothetical but they may eventually be produced on Earth in particle accelerators such as the Large Hadron Collider or detected in cosmic ray collisions in our atmosphere. Such empirical data could greatly aid the development of a theory of quantum gravity.

Micro black holes would be interesting to observe because of their short lifespan. Black holes evaporate over time (see Hawking radiation) and the less the mass, the faster one does. Scientists hope to observe the "death" of a very small black hole.

Physicist Brian Greene has suggested that the electron may be a micro black hole. Small black holes would look like elementary particles because they would be completely defined by their mass, charge and spin. Since the electron is not observed to evaporate, an explanation for the electron's stability is needed. An explanation is also needed for the extreme time dilation required at the micro black hole photon capture circumference (approximately 1.025×10^-22 seconds per second). A ring singularity at the photon capture region could explain this, but the question of stability remains.

The Planck mass

The maximum mass of a micro black hole in which quantum mechanical effects play a dominant role is the Planck mass. This mass is also the value where the black hole's Schwarzschild radius and its Compton length are equal. This distance is also equal to the Planck length.

If two aggregates of fermions with mass-energy equal to Planck mass (or energy) collided in a particle accelerator within a distance of a Planck length, they would form a micro black hole. However, such a reaction would require energy levels orders of magnitude larger than we can currently produce.

Current predictions for the behaviour of a black hole with a mass less than Planck mass are inconsistent and incomplete.

See also

• black hole, a general survey

Classification by type:

• Schwarzschild or static black hole
• rotating or Kerr black hole
• charged black hole or Newman black hole and Kerr-Newman black hole

A classification by mass:

• micro black hole and extra-dimensional black hole
• primordial black hole, a hypothetical leftover of the Big Bang
• stellar black hole, which could either be a static black hole or a rotating black hole
• intermediate-mass black hole
• supermassive black hole, which could also either be a static black hole or a rotating black hole

Sources

• Quantum Mechanical Black Holes: Towards a Unification of Quantum Mechanics and General Relativity -- http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:quant-ph/9808020

External links

• BBC "Horatiu Nastase says his calculations show that the core of the (particle accelerator) fireball has a striking similarity to a black hole. His work has been published on the pre-print web site" arxiv.org.