Particle acceleration disasters cause galactic extinction- that outweighs

An example par excellence of a Q = 0 event is a vacuum phase transition or a comparable quantum field collapse. Such an event would not only extinguish humanity but also completely and permanently destroy the terrestrial biosphere. Coleman and De Luccia first mentioned the possibility that such a disaster might be caused by the operation of high-energy particle colliders used in physics research.(40) This possibility has since been widely discussed,(10,41−46) and has motivated objections to the operation of high-energy particle colliders, including most recently the Large Hadron Collider.(46,47) Three specific threats are relevant: (1) triggering vacuum phase transition through creation of an expanding bubble of “new” vacuum state, (2) accidental production of charged strangelets, which could transform all Earth’s mass into strange matter, and (3) accidental production of a mini black hole falling into Earth’s center and subsequently destroying our planet. Although smacking of science fiction, this idea has been seriously considered even by high-level 1504 Cirkovi ´ c, Sandberg, and Bostrom ´ administrators of modern particle-accelerator laboratories.(48) This is not only an eschatological issue for humanity: a vacuum phase transition would also destroy the habitability of the universe for any other observers in our future light cone. Even if the chance of such a disaster is remote, its catastrophic impact would be so enormous that it deserves close scrutiny. Hut and Rees, in an important pioneering study of the problem of high-energy physics risks, suggested that concerns about particle colliders can be reasonably dismissed because high-energy particle collisions occurring in nature, such as those between cosmic-rays and the Earth’s atmosphere or the solid mass of the Moon, are still orders of magnitude higher than those achievable in human laboratories in the near future.(10) With plausible general assumptions on the scaling of the relevant reaction crosssections with energy, Hut and Rees concluded that the fact that the Earth (and the Moon) have survived cosmic-ray bombardment for about 4.5 Gyr implies that we are safe for the foreseeable future. For example, if the probability of a high-energy physics disaster in nature is 10−50 per year, then a doubling or even 10-fold increase of the risk through deliberate human activities is arguably trivial. The Hut-Rees argument should provide us no comfort, however, as it fails to correct for anthropic bias. A vacuum phase transition is an event for which Q = 0. Probability estimates based on observations of the Earth’s and Moon’s existence are thus completely unreliable. Moreover, the unreliability of these estimates applies to both naturally occurring and humaninduced vacuum phase transitions. (Hut and Rees also conclude, completely justifiably, that the number of potentially risky events in any conceivable human accelerator is much smaller than in the cosmicray interactions in nature.) Unfortunately, the same error is repeated in the recent Large Hadron Collider (LHC) safety study, where the duration of the solar system thus far is invoked as part of the arguments for accelerator safety.(46)