The Potential for Danger in Particle Collider Experiments>
Available at: Risk Evaluation Forum, February 2008---------------- Return to Risk Evaluation Forum Home Page

This is an abstract of a longer paper that you can find on the risk evaluation forum: "Black holes produced on Earth could destroy planet"
February 2008 LHC Risk 2008-02

In a few words: Black holes could be produced on Earth in a few month in the beginning of the year 2008 in the LHC accelerator, using "collisions with opposite speed particle". This way of experiments means that black holes could be captured by Earth gravity. Evaporation of black holes has never been tested. In case of evaporation-failure we could have a risk of complete destruction of the whole planet. If we count also others accelerator incertitude, this risk could be estimated to more than 4%

The LHC particle accelerator will be the most powerful in the world. It will smash fundamental particles into one another at energies like those of the first trillionth of a second after the Big Bang, when the temperature of the Universe was about ten thousand trillion degrees Centigrade [from Ref.11].

1/ Micro black holes (MBH) could be produced in the LHC [Ref.1].
CERN [Ref.4 & Ref.5] indicates a possible rhythm of producing "one micro black hole every second".
The probability of MBH production depends of validity of physical theories with more than 4 space-time dimensions (String theory needs 10 dimensions, M theory and branes theories need 11dimensions, etc..).
The probability of validity of these theories could be estimated at 50%.
That means that black holes could have a 50 % probability to be produced in LHC.

2/ CERN study 2003-001 [Ref.1] and also [Ref.2] are risk-evaluation studies from "LHC Safety Study Group". These evaluations are very important because a risk could exist of a possible complete destruction of planet Earth.
CERN study [Ref.1] indicates "Black hole production does not present a conceivable risk at the LHC due to the rapid decay of the black hole through thermal process".
The problem is that the thermal process (that means evaporation of the black holes described by Stephen Hawking) is totally theoretical and no experiment has proved its truth.

This evaporation is contested et could only be valid in case of specials and atypical black holes [Ref.8].

In several surveys, physicists have estimated a non-trivial probability that Hawking evaporation will not work. [Ref.6]

Every good physical theory could be wrong until it has been tested!
A minimal estimation of Hawking evaporation failure could be of 20%.

3/ Accelerator experiences of shooting high-energy particles with opposite speeds create on Earth conditions different from natural collisions due to cosmic rays because the speed of the particles resulting of the collision in this case is close to zero.
This means that the particles created could more easily be captured by Earth gravity.

4/ LHC physicists agree that in case of non-evaporation black holes could be captured by Earth gravity [Ref.3] and [Ref.7].
Using LHC during ten years calculus from [Ref.3] indicate that 3.160 (US notation 3,160) MBH could be captured by Earth and from [Ref.7] that only 10 MBH would basically get trapped, orbiting around the centre of Earth.
LHC physicist indicate that even in these case there will be non-danger because these black holes will need a very long time to capture atoms.
From [Ref.3] we see that are needed "3 hours to gobble a single atom" and from [Ref.7] "100 hours would be needed to gobble a single proton". With this last evaluation, LHC physicists indicate that "it would take much more than the age of universe to destroy even one milligram of Earth material".

This calculation has also never been tested and could have to be modified using others calculus factors as we will indicate in this study (see very important discussion about processes for absorption of Earth matter).

We have to consider that in any case, as for all the calculus and the theories non tested, the minimal estimation of failing of such calculation could be of 20 %. We can then calculate the global risk:
Using a probability of black holes production of 50%, non evaporation 20% and 20% for failure in evaluation of absorption of matter, we will have 50% x 20% x 20% which means risk of 2%

If we count also others accelerator incertitude, this risk could be estimated more than 4% (See important discussion in the study and the complement).

In any case, even a risk of 2% is an important risk for the global planet and cannot be accepted.

In this times when is proposed lasting development for the planet, the precaution principle indicates strongly not to experiment, with opposites speed particles collisions.

References:

1.. Study of potentially dangerous events during heavy-ion collisions at the LHC : Report of the LHC Safety Study Group. CERN 2003-001 28 February 2003.
Avalaibable at : http://www.risk-evaluation-forum.org/links.htm

2.. Study of potentially dangerous events during heavy-ion collisions at the LHC :
LHC Safety Study Group. J.P. Blaizot, J. Iliopoulos, J. Madsen, GG. Ross, P. Sonderegger, H-J. Specht * No date for this study, available Internet May 2004 +.

3..E-mail exchange between Greg Landsberg and James Blodgett March 2003.
James Blodgett Internet Forum. http://www.risk-evaluation-forum.org/links.htm
Avalaibable at : Risk Evaluation Forum PO BOX 2371 Albany, NY 12220 B 0371 USA f

4.. High energy colliders as black hole factories: the end of short distance physics Steven B. Giddings, Scott Thomas. Phys Rev D65 (2002) 056010

5.. CERN to spew black holes Nature 02 October 2001

6.. Results of several Delphi groups and physicist questionnaires, James Blodgett, Risk Evaluation Forum, forthcoming.

7.. http//www.freerepublic.com/focus/f-news/1705282/posts "Despite Rumors, Black Hole Factory will Not Destroy Earth" 19 September 2006 Charles Q.Choi .

8.. La Recherche NE411 Septembre 2007. théorie des cordes p33.