Click Here to Return to Risk Evaluation Forum Home Page


New prediction of black hole production at new LHC energy (DESPITE THE TITLE!!)

Ahmed Farag Alia, Mir Faizald, and Mohammed M. Khalile, Absence of black holes at LHC due to gravity's rainbow, Physics Letters B, Volume 743, 4/9/2015, Pages 295–300. See web version

The above is presented in more accessible fashion, and with less sleight of hand, in the following article, which is based on an interview with the authors of the above paper.

Lisa Zyga, Detection of mini black holes at the LHC could indicate parallel universes in extra dimensions,, 3/18/2015. See web version Accessed 3/22/15.

The first paper predicts black holes at the energy level of the rebuild LHC, if certain constraints and theories are true. It is amusing that the paper's title seems to be about absence of black holes, and its conclusion says that black holes are a prospect for potential future colliders, not for the LHC. We guess that they needed this misdirection to achieve publication. To be fair, part of their point is an absence of black holes in the earlier runs before the LHC was enhanced, frustrating to string theorists who were looking forward to black hole production because black holes (if they dissipated via Hawking radiation) would prove their theory. The paper rescues string theory by explaining why black holes have not yet been seen via new calculations that predict black hole production at 11.9 TeV given ten dimensions, a number of dimensions sometimes predicted by string theory. The design energy of the enhanced LHC is 14 TeV. The second article cited above, based on an interview with the authors of the first, clearly states: "Since the LHC is designed to reach 14 TeV in future runs, these predicted energy requirements for black hole production should be accessible."

Recent statements that there is a problem:

Eric E. Johnson, "The Black Hole Case: The Injunction Against the End of the World," Tennessee Law Review, Vol 76, pp.819-908.
This paper provides an excellent analysis of the philosophical and legal factors, and a good review of the physics. This paper has been reviewed in several scientific and policy publications. A brief version appeared in New Scientist. See web version

Rainer Plaga, "On the potential catastrophic risk from metastable quantum black holes produced at particle colliders," arXiv 08081415v1, Aug 10, 2008. See web version

Otto. E. Rössler, "Abraham-Solution to Schwarzschild Metric Implies That CERN Miniblack Holes Pose a Planetary Risk" Get PDF version

Toby Ord, Rafaela Hillerbrand, Anders Sandberg, "Probing the Improbable: Methodological Challenges for Risks with Low Probabilities and High Stakes," Journal of Risk Research 13(2) (2010) pp. 191–205.
Asserts that the probability that collider advocates are wrong about collider safety is higher than the very low probabilities supposedly computed by some of them. See web version

Papers assuring the public that nothing could possibly go wrong:

These are in time order. The last are the latest and most important. The first two are outmoded, the first because it said that black hole production was beyond reach of any collider, the second because it relied on Hawking radiation to dissipate black holes. Papers listed below dispute both points. It is a serious problem that safety studies supposed to be adequate to protect Earth should become outmoded, raising the question of whether physics in this area is mature enough to provide adequate safety considerations.

W. Busza, R.L. Jaffe, J. Sandweiss, and F. Wilczek; "Review of Speculative ‘Disaster Scenarios' Brookhaven, 2000
There was concern, and even a lawsuit, before implementation of the RHIC (Relativistic Heavy Ion Collider) at Brookhaven National Laboratory, (in Upton, New York, USA) now on line and apparently safe. (It is not completely sure that it is safe. In some scenarios, a low-probability effect takes a while to appear.) "Review of Speculative ‘Disaster Scenarios'" was posted by a Brookhaven group in response to these concerns. It is ironic that they rated mini black hole production as highly improbable since shortly afterward, many papers appeared predicting black hole production. They spent more time addressing the issue of strangelets. Get PDF version

J.-P. Blaizot, J. Iliopoulos, J. Madsen, G.G. Ross, P. Sonderegger, and H.-J. Specht, "Study Of Potentially Dangerous Events During Heavy-Ion Collisions At The LHC: Report Of The LHC Safety Study Group" CERN, 2003
This is CERN's web posting similar to the posting above. It considers many scenarios, and concludes that there is no risk. However, it assumes that mini black holes will decay by thermal processes (Hawking radiation), and concludes that there is no danger. (See page 12, equation 19.) The idea that Hawking radiation might not work, as is suggested by several papers listed below, is not explored. Strangelet risk is dismissed based on Madsen's work in the paper listed below, which is now questioned by the paper below that. While discussing cosmic rays the report concludes that "the worst-case scenario cannot be excluded based on these data alone." (Page 5) Get PDF version
CERN is the European Organization for Nuclear Research. Here is a link to the CERN website Go to CERN website

John Ellis, Gian Giudice, Michelangelo Mangano, Igor Tkachev, and Urs Wiedemann, (Large Hadron Collider Safety Assessment Group(LSAG)) "Review of the Safety of LHC Collisions," CERN June 2008.
This is a recent report, produced, we think, due to the inadequacies of the previous versions. Most of the considerations of black hole risk are incorporated by reference from the paper below. Get PDF version

Steven B. Giddings and Michelangelo L. Mangano, "Astrophysical implications of hypothetical stable TeV-scale black holes
This is a supplementary paper by one of the participants in the LSAG report, and referenced in that report. We appreciate that they tentatively agreed with many of the points made by collider critics, and went beyond them to find new safety factors. For example, an analogy between colliders and cosmic rays was presented by collider advocates to demonstrate safety. If collider collisions could cause trouble, cosmic ray collisions should already have done so. However, critics said that this was a false analogy. Cosmic-ray-created black holes would be moving rapidly and could be modeled to consistently zip through earth like neutrinos without stopping, whereas collider-created black holes would be slower and should occasionally stop and cause trouble. Giddings and Mangano tentatively agreed with critics on this point, but presented an equation that purported to show that cosmic-ray-created black holes would stop in white dwarf stars and in neutron stars if they could cause trouble in earth, making white dwarf and neutron star lifetimes shorter than observed. Therefore, they contend, colliders should not cause trouble. Get Web version
For important challenges to this paper, see the Plaga and Rössler papers referenced above, and the working paper on our forum page.

Papers and books about collider risk:

Francesco Calogero, "Might a laboratory experiment destroy planet Earth?" Interdisciplinary Science Reviews 25, 191-202 (Autumn 2000).
This paper does not discuss the physics about which we are especially concerned, and so ranks black hole formation as improbable. It considers mainly strangelet production.

Mark Leggett, "Affidavit Of Mark Leggett In Support Of Tro And Preliminary Injunction," 2008 Details several departures from risk assessment best practices by collider advocates. Get PDF version

Harry V. Lehmann, No Canary in the Quanta: Who Gets to Decide if the Large Hadron Collider is Worth Gambling Our Planet? Green Swan, 2009. Also available in a Kindle edition.

Safety of particle collisions at the Large Hadron Collider, Wikipedia, accessed 3/6/10.
Somewhat biased in tone, as collider advocates outvote critics. However, contain extensive references and coverage of most issues. Go there

Papers and books about global risk that consider collider risk:

Adrian Kent, "A critical look at risk assessments for global catastrophes," Risk Analysis, Vol. 24, No. 1, 2004
This paper discusses the mathematics of expected value (probability times cost) as applied to this type of problem. It considers the high expected loss resulting from low probability risks when the loss is very large. See web version

Mark Leggett, "An Indicative Costed Plan for the Mitigation of Global Risks," Futures, (2006) Vol. 38, p. 778-809.
Considers the range of global risks and the costs of mitigation. The risk from colliders is considered the easiest to mitigate and the most pressing, and is ranked first. See abstract

Richard A. Posner, Catastrophe: Risk and Response, (Oxford University Press, 2004).
Posner is a judge and a law professor. He attempts to apply the legal system and legal concepts to issues of ultimate risk.

Martin Rees, Our Final Hour, (Basic Books, 2003).
Sir Martin Rees is England's Astronomer Royal and president of the Royal Society. The book is a good read; Sir Martin is a good writer. His warning about colliders (pp. 119-129) parallels that of this website. He mentions the new multidimensional string theories, and points out how cosmic rays collisions are not exactly equivalent to collider collisions. He is very good on the philosophical implications. He does miss one point. He assumes Hawking radiation will work, and therefore estimates the probability of trouble from mini black holes as lower than we might. He focuses concern on other potential collider products. The book is an excellent review of humanity's hazards and opportunities on a universal scale.

Papers predicting black hole production at colliders:

Steven Giddings and Scott Thomas, "High energy colliders as black hole factories: the end of short-distance physics," Physical Review D 65(5) (2002) 056010. See abstract

Savas Dimopoulos and Greg Landsberg, "Black holes at the Large Hadron Collider," Physical Review Letters, 87(16) 161602, (2001). See abstract

Greg Landsberg, "Discovering New Physics in the Decays of Black Holes," Physical Review Letters, 88(18) 181801 (5/6/2002) See abstract

Nima Arkani-Hamed, Savas Dimopoulos, and Georgi Dvall; "The Universe's Unseen Dimensions," Scientific American, Aug 2000. Pages 62-69.
This paper develops a theory that the multiple dimensions which string theory postulates to be visible on very small scales, may be visible on somewhat larger scales. The motivation is to unify gravity with other forces that are much stronger. The authors state (on page 62) "If the theory is correct, upcoming high-energy particle experiments in Europe could see unusual processes involving quantum gravity, such as the creation of transitory micro black holes." Our concern is that they might not be transitory. This paper is not available on the Internet.

Panagiota Kanti, "Black Holes in Theories with Large Extra Dimensions: a Review," International Journal of Modern Physics A 19 (2004) pp. 4899-4951
Reviews many papers that assert that black holes can be created in high energy particle collisions. (Also shows that the radius of a black hole is many orders of magnitude larger given multiple dimensions, an important result for accretion.)
See web version

Also note the new paper predicting black hole production discussed at the top of this list.

Papers that question Hawking radiation:

Adam D. Helfer, "Do black holes radiate?" Reports on Progress in Physics. Vol. 66 No. 6 (2003) pp. 943-1008.
Questions the existence of Hawking radiation. See web version

William G. Unruh and Ralf Schützhold, "On the Universality of the Hawking Effect," Physics Review D 71(2005) 024028. Considers plausible quantum gravity scenarios in which black holes radiate at rates very different from those proposed by Hawking, or do not radiate at all. See web version

V.A. Belinski, "On the existence of quantum evaporation of a black hole," Physics Letters A 209(1) (1995) pp. 13-20.
Asserts that Hawking radiation does not exist.

Papers regarding strangelets at colliders:

Jes Madsen, "Intermediate mass strangelets are positively charged," Physics Review Letters 85 (2000), 4687-4690
Claims that, since negative charge is required for growth, strangelets are safe. See web version

G. X. Peng, X. J. Wen, Y. D. Chen, New solutions for the color-Favor locked strangelets Physics Letters B 633 (2006) 314-318. Says that strangelets may have negative charge after all. See web version

Richard J. Wagner, The Strange Matter of Planetary Destruction.
Discusses the potential for production of strangelets at colliders, and whether they could destroy earth. See web version

Click Here to Return to Risk Evaluation Forum home page