24

When I was a kid, there was a lot of discussion on electronic media channels that the run of CERN's Large Hadron Collider would lead to black holes. At that time, the president of India, APJ Abdul Kalam, said there were no chances for destruction. You can read his statements in the article Kalam allays fears of 'Dooms Day':

"It is just that the scientists in Geneva want to establish their own belief of the creation of universe as caused by the Big Bang," Kalam, a scientist, told reporters on the sidelines of a function at the Army Hospital here.

Narrating his personal experience when he visited the CERN site in Geneva recently, Kalam said it would not create any threat to the lives of the people, but would help in enhancing their living standards.

I came to know that there is a run three scheduled today. After run one has begun that time, people believe that destruction due to blackholes may happen after 10-15 years. And still, I can see some channels and users of online platforms say that there is the possibility of destruction after some fast-moving particle collision. Some of the viewers of CERN's channels also comment that there may be a possibility of destruction.

Is there any rational basis for such claims related to destruction? If yes, then what can happen in the worst case?

Laurel
  • 30,040
  • 9
  • 132
  • 118
hanugm
  • 495
  • 1
  • 4
  • 9
  • 10
    This question asks the question in a biased way, but I can't see how to fix it without invalidating the first answer. Imagine a question that asked "Is there any possibility that a pillow fight could be devastating? What can happen in the worst case?" It is calling for evidence in one direction only. – Oddthinking Jul 05 '22 at 18:46
  • 6
    I think this is a fine question, and well written. It's not "biased", it clearly gives a clear example of a claim (by one of the world's major politicians), and seeks actual explanations. – Fattie Jul 06 '22 at 20:58
  • The folks writing these reports don't have enough information to credibly deny risk; rather, the mainstream opinion tends to be that it's _probably_ going to be okay, in the sense that a specific threat hasn't been identified. – Nat Jul 08 '22 at 16:56
  • Kind of a weird fit for SE.Skeptics. I mean, this is a popular claim, so I definitely get why it might be asked here. But the obvious answer -- that the mainstream isn't really sure -- might be unsatisfying, inviting folks to delve into speculation. And I'm not sure that folks outside of the scientific world really tend to get how speculation works.. there seems to be a lot of over-confidence in tentative hypotheses. – Nat Jul 08 '22 at 17:05
  • @Nat: Right, but the same answer can be given for pillow fights. (I mean, no plausible mechanism has been identified by which pillow fights could destroy the planet, but...) – Oddthinking Jul 11 '22 at 14:45
  • 1
    @Nat See my answer. There is nothing happening in the LHC that does not happen in the upper atmosphere on a daily basis. This simple emperical observation makes the mainstream very sure that there is no significant risk. – TimRias Jul 11 '22 at 19:26
  • @TimRias: Cosmic-rays aren't the same thing: they're generated differently, tend to travel large distances from their source before colliding, tend to collide in less dense environments with more momentum away from Earth's, etc.. Some analyses have commented on some of these things (such as observations of compact-stars apparently existing), but they're not exactly equivalent things. I mean, sure, it seems like the experiments are _probably_ going to not cause major harm, but such assessments tend to be guesswork. – Nat Jul 12 '22 at 19:06
  • @TimRias: I feel like I may be making a somewhat academic point just to make it, just.. traditionally, researchers seem to miss the harms that could come from their work, always seeming surprised by the consequences that were outside of their frame before such things became seemingly obvious later. It just seems weird for folks to declare that such unknown concerns couldn't exist here. – Nat Jul 12 '22 at 19:16
  • @TimRias: To give two examples.. **(1)** A lay-friendly example might be a Dawn-Hunter scenario, where such experiments have some faster-than-in-light-cone consequence that'd tip off aggressive alien life, triggering a response. **(2)** The perhaps-more-concerning scenario would be something like the concept behind a false-vacuum, only more like disturbing an equilibrium on a more local scale. Which feels like a scenario that'd take a lengthy exposition just to explain, but it'd seem to be a larger practical concern. – Nat Jul 12 '22 at 19:19
  • @Nat Almost all experiments done in a lab are not exactly equivalent to other events. That is why they are done in labs. What makes this particular experiment different in your eyes. Cause if the criterium is the creation of unique physical circumstances that have not previously occured, the LHC scores nowhere near the most unique. – TimRias Jul 12 '22 at 19:45
  • @TimRias: I'm not suggesting that this particular experiment is unique in the quality of carrying significant risks. I guess I do wonder about the risk-to-payoff ratio though.. I'm skeptical that we're liable to have significant theoretical advancements from this sort of work before AI displaces humans, such that any risk that would exist would seem to be taken prematurely. That said, I'm commenting here not to object to the LHC in a general sense but rather just to comment on this question as it appears on SE.Skeptics. – Nat Jul 12 '22 at 19:55

1 Answers1

80

No.

There is no chance of catastrophic consequences of the CERN run. CERN Website LSAG report

The simplest evidence of this comes from the fact that nothing particularly special is happening in the LHC. The collision that the LHC generates under lab conditions happen regularly in the Earth's atmosphere when it is hit by high-energy cosmic rays.

In this sense, the LHC run is much safer than, say, the creation of the first Bose-Einstein condensates, which generated conditions that (for as far as we know) have never existed anywhere in the history of the universe.

For the specific "threat" of the creation of micro black holes, note:

  1. According to the laws of nature as we currently understand them, it is impossible to form black holes at the LHC. Doing so would require a significant deviation from the known laws of physics (e.g., the existence of large extra dimensions).
  2. Even if a micro black hole would be created, theory still predicts that they would almost instantly evaporate due to Hawking radiation.

So, for something to happen, our understanding of nature has to be wrong in very, very significant ways.

Of course, one can argue that one should not "gamble" the lives of billions of people based on what a bunch of theoreticians are saying.

For this, we return to the argument of cosmic rays. If the LHC is to produce black holes, then cosmic rays colliding with the Earth and other celestial bodies must also regularly produce micro black holes. Due to the high energy of cosmic rays, hypothetically stable black holes produced by them would also travel at high velocities, fast enough to escape the Earth. However, if this happens on Earth, it also happens on neutron stars, which would be dense enough to stop the created black hole. If this were to happen regularly, neutron stars would all be unstable and collapse to black holes in short amounts of time. The fact that we observe neutron stars that are stable over many decades tells us that this is not the case.

Community
  • 1
TimRias
  • 3,677
  • 2
  • 14
  • 16
  • 1
    Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/137614/discussion-on-answer-by-timrias-is-there-any-possibility-that-cerns-large-hadro). – Oddthinking Jul 08 '22 at 01:43