Why are Mad Scientists Allowed to Dabble in Potentially Universe-Destroying Experiments? By Brian Simpson

     There is so little criticism of the sorts of dangerous experiments that high energy physicists engage in, mainly because the ordinary people know so little about elementary particle physics and high energy collisions. However, the potential does exist to destroy not only the Earth, but by a chain reaction, the entire universe.
  https://www.zerohedge.com/technology/meet-mad-scientists-performing-universe-breaking-experiments

“CERN is currently working on a lofty plan to revamp its “flagship accelerator complex” over the course of the next two decades. But a more powerful particle accelerator could be the very last thing the world needs, according to British cosmologist Martin Rees. Rees, a well-respected expert in his field, issued a grave warning to the scientific community about particle accelerator experiments gone awry in his book On The Future: Prospects for Humanity published late last year. These experiments meant to push the boundaries of nature and physics, he writes, “might do something far worse — destroy the Earth or even the entire universe.” As alarmist as it sounds, this is no crackpot notion. Rees writes that, "Maybe a black hole could form, and then suck in everything around it [...] The second scary possibility is that the quarks would reassemble themselves into compressed objects called strangelets. That in itself would be harmless. However, under some hypotheses a strangelet could, by contagion, convert anything else it encounters into a new form of matter, transforming the entire earth in a hyperdense sphere about one hundred metres across."

If the idea of a black hole being created by sheer accident here on earth, almost instantaneously compacting the entire earth into an ultra-dense object the length of a football field isn’t scary enough, this isn’t even the worst-case scenario. The third, and by far the most disturbing way in which a particle accelerator could potentially undo the world as we know it is by taking the entire universe down with it by means of a "catastrophe that engulfs space itself.” The book goes on to elaborate on this impossible-to-fathom idea. “"Empty space - what physicists call the vacuum - is more than just nothingness. It is the arena for everything that happens. It has, latent in it, all the forces and particles that govern the physical world. The present vacuum could be fragile and unstable. "Some have speculated that the concentrated energy created when particles crash together could trigger a 'phase transition' that would rip the fabric of space. This would be a cosmic calamity not just a terrestrial one." CERN, of course, has dismissed the ideas put forward by Rees and maintain that their experiments and their groundbreaking Large Hadron Collider pose no such threat to the world or the universe or even its hometown of Geneva, Switzerland. In a statement on its website CERN assures readers that “the Large Hadron Collider (LHC) can achieve an energy that no other particle accelerators have reached before, but Nature routinely produces higher energies in cosmic-ray collisions,” and that a new safety analysis has been conducted, with all findings backing up the 2003 report in that “ LHC collisions present no danger and that there are no reasons for concern.”

In Rees own words, however, even though the various potential doomsdays via particle accelerator are unlikely, "given the stakes, they should not be ignored.” NBC’s tech and innovation news branch MACH points out that Rees’ call for concern has its place in a long and historized legacy of “experts cautioning that modern technology could lead us to disaster,” from atomic bomb testing igniting the atmosphere to astronauts bringing incurable space diseases back from the moon. Just because these worries haven’t come true, however, doesn’t mean that such fears should be dismissed--especially coming from an industry veteran like Rees. Every technological advancement in human history has been made possible by the boundless curiosity and hubris of man. Scientific inquiry and an outright refusal to explain away or simply accept the infinitely complex world and universe we live in is quite possibly the greatest gift of our species. But as we continue to push the bounds of physics, nature, and science, we should always endeavor to expect the unexpected and consider every possible outcome so we can best mitigate the consequences.”

     The mathematical issue here is that the physicists dismiss the idea of the  Earth and the universe being destroyed as of low probability, and can therefore be discounted. However, in decision theory, and risk analysis, a concept of expected utility, or in this case disutility, must be applied, which involves multiplying the probability of disaster by the risk. This is the formula that is needed and it shows that the disutility or risk involved with potentially catastrophic existential risk, cannot be discounted even if the probability is very low. The cost being high makes the function substantial.
  https://en.wikipedia.org/wiki/Global_catastrophic_risk