Posner’s book surveys four civilization-ending-scale risks (asteroid impact, particle-accelerator chain reaction, abrupt climate catastrophe, bioterrorism) through a cost-benefit lens: even at vanishingly small probability, a risk with effectively infinite disutility (extinction) can have expected cost large enough to justify substantial mitigation spending or regulatory review, contra the intuition that “very unlikely” settles the matter. The RHIC/collider chapter uses the strangelet and black-hole scenarios as the running example and concludes existing self-review by physicists (comparable to LSAG-style panels) is an inadequate check given the reviewers’ institutional stake in the experiment proceeding; he proposes a standing federal catastrophic-risks review board with authority to forbid experiments found to pose undue existential risk. relevance_note: A second independent “the reviewing body’s incentives, not just its physics, are the load-bearing weak point” argument, from a law-and-economics rather than legal-procedure or physics angle — converges with Calogero’s institutional critique from a different discipline.