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Miscalculation Invalidates LHC Safety Assurances
KentuckyFC writes "In a truly frightening study, physicists at the University of Oxford have identified a massive miscalculation that makes the LHC safety assurances more or less invalid (abstract). The focus of their work is not the safety of particle accelerators per se but the chances of any particular scientific argument being wrong. 'If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect,' say the team. That has serious implications for the LHC, which some people worry could generate black holes that will swallow the planet. Nobody at CERN has put a figure on the chances of the LHC destroying the planet. One study simply said: 'there is no risk of any significance whatsoever from such black holes.' The danger is that this thinking could be entirely flawed, but what are the chances of this? The Oxford team say that roughly one in a thousand scientific papers have to be withdrawn because of errors but generously suppose that in particle physics, the rate is one in 10,000."
This is voodoo science. And I don't mean the LHC experiments.
I mean the TFA that in essence claims that because an expert may be wrong, any probability the expert assigns to a risk can be ignored and inflated by as much you feel like it. Talk about bias.
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The purpose of the LHC is noble, and results could be what we need to get off this rock and really dominate the galaxy. If they destroy the Earth... meh, it was a good try. Maybe next time.
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Opponent: Oh crap, you're whacking things together, it could destroy the earth, crazy scary technology we don't understand!
Proponent: That could never happen.
Opponent: OMG yes it could you don't know wtf you only have studied this shit your whole life you're not a sane normal rational person like the boys in Alabama!
Proponent: Look, we've done tons of calculations; we've compared this against real-world natural occurrences; we've considered the number of times the conditions we've come up with have occurred in our lifetimes, and it's huge. We're just scaling it down to a laboratory level so we can observe it in a controlled environment. It can't break anything.
Opponent: BUT YOU COULD BE WRONG!!!!
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I don't see the problem, facts:
1) We will all die some day.
2) The solar system will stop working some day.
So what's the problem? Sure it may kill us and all life on the planet, but does it really matter? We're screwed anyway.
> I STILL don't think the LHC will kill us all but the fact we're debating it says something.
Yes, it says that people are easily scared by things they do not understand. See also: wireless, mobile phones, things that have a 'chemical' smell... Ask some random people what would happen if the sun were to be replaced instantaneously by a black hole with a mass equal to that of the sun (moving in the same direction as the sun with the same speed, etc). Most people will reply that the earth would get 'sucked' in the black hole... if you don't even understand gravity you have no place in a debate concerning the LHC.
Everyone is entitled to an _informed_ opinion.
The article is a pile of BS topped by a sensationalist (and completely wrong) headline. The paper abstract is interesting, but that's it.
Essentially the blog article makes the jump from 1 in 1000 papers being withdrawn because of "an error", any error, to the idea that the safety of the LHC is "invalid" due to a "massive miscalculation."
How can a hypothetical miscalculation be "massive?" Anyway, you can't just take an average retraction rate for papers and assume it applies to anything you like. The arguments for the LHC being safe are based on well established science. That is, for the LHC to destroy the world not only would ONE paper have to be wrong, but a LOT of papers would have to be wrong, and all in the same direction.
paranoid person: The LHC is going to cause a black hole!
scientist: No, the LHC is not going to cause a black hole.
paranoid person: The chances of a scientist being wrong is 10%, therefore there is a 10% chance that the LHC will cause a black hole!
If you had super powers, would you use them for good, or for awesome?
Seriously, nothing to see here. This is truly an embarrassment to Slashdot (if that's even possible). Just move along.
Okay seriously?
The probability that Jimbo is wrong is unrelated to the probability of your tire failing. If jimbo says that you have a 1% chance of your tire failing, but there's a 50% chance that jimbo is wrong we can reach the following conclusion: There is a 50% chance that your tire has a 1% chance of failing. There is a 50% chance that your tire has some other probability of failing. Some other probability of failing includes values such as 0%, .5%, and 2%. It also includes a 100% probability of your tire failing.
However, we have to assume that Jim isn't pulling the 1% figure out of his ass. If your tire was 100% likely to fail, we can still assume that Jim based his statement on a reasonable analysis. Perhaps Jim didn't notice a nail in your tire, but without knowing the quality of Jim's inspection of your tire, or without having access information Jim doesn't have, it's hard to say that he has a 50% chance of being wrong.
Finally, in some cases a professional will include a certain amount of leeway in his figure. Chances are, Jim fully inspected the tire and doesn't see any reason why it would fail prematurely. Chances are, that 1% is left as wiggle room in case of invisible manufacturing defect or a mistake in his evaluation. In this case, Jim has already factored into his evaluation the chances that he's incorrect.
With all this uncertainty, it does however highlight two certainties.
First, they have proved they can make mistakes. (While this should be obvious, it is however so often assumed that as they are the best of us, then they must know what they are doing).
Second, it proves they do not know precisely what they are doing. (Again this should be obvious, (as there would be no point in building the LHC, if they knew precisely what was going to happen). But it again highlights how its assumed they do know what they are doing, when in fact they cannot know).
This doesn't prove the LHC is dangerous, but it does prove they cannot prove the LHC isn't dangerous.
At the same time, we have theories which can show possible dangers. Now possible doesn't mean probable, but it also doesn't mean impossible.
Even the argument about atmospheric collisions is flawed, as the set of conditions inside the LHC is different to in the atmosphere. For example atmospheric collisions are very unlikely to have any chance of many Higgs Bosons in collision with each other whereas in the LHC it is possible, and thats just one example difference. Also we have no idea how multiple Higgs Bosons will behave or decay in groups or if it will allow them to interact or merge with other particles and how continuing collisions would affect them).
I don't believe they would ever stop these experiments, as too many people involved with the science (and the money behind the LHC) have such intense desire to learn from the experiments. But I do at least hope, they use extreme caution and so only slowly, (over a period of a many months) move to (even currently possible) higher energy collision experiments, in very small increments. While its easy to assume they will, they have shown too many times how worried they are other experiment teams are going to get to the noble prize winning results first, so they do have extreme pressure on them, to rush into the higher energy experiments to show results fast).
This is the only experiment in human history where we cannot learn from our mistakes. We have to be 100% certain it is safe, before each new step up is even attempted. (Too many mistakes have already been made and we have yet to even get into the more possible dangerous aspects of the experiments).
No, it's not a mistake. It all comes down to the fact that there are two general types of interpretations of probability:
Basically, you're treating this as an argument about probability in the first sense, when it is really about probability in the second sense. The argument is that even if your formulas lead you to asssign a degree of confidence of .00000000000001 to the proposition that the LHC will not destroy the Earth, that means very little if we assign a degree of confidence of .000001 to the proposition that you are wrong.
The point now, which other posters in this thread have made in other ways, is that the frequency model for probability theory is not relevant here, because this situation is not like a coin toss. For the situation to be like a coin toss, we would have had to do something like run the LHC a gazillion times, and observe how many of those times it ended up destroying the Earth. Therefore, the probabilities must be interpreted as degree of belief, and the number produced by any formula must be tossed out if the probability of getting the formula wrong is bigger than that number.
The assumption you're making here is that the number is the "probability of the event." Again, it is not; it is the degree of belief warranted to a specific proposition, given some other information.
Are you adequate?
It's both right and wrong. The conclusion that we can't trust the probability of disaster if we got it wrong is correct...bloody obvious, but correct. The part where they use the population of the Earth to determine whether the LHC "risk" is acceptable is frankly insane. This seems to suggest that if Bird flu wipes out half the population then the "risk" of running the LHC is suddenly now more acceptable?
Black holes do not require lots of mass, they require lots of density. If matter is packed into an area less than that matter's Schwarzschild radius, you have a black hole. There is a real theory that this experiment will create a black hole. However, the same theory that says that a black hole could be created also says that black holes should be created all the time in Earth's upper atmosphere. Small black holes are harmless because they rapidly evaporate. Regardless of what will be created, the LHC is just recreating events that occur all the time in our upper atmosphere, so saying that it could be harmful is kinda stupid -- if there were a significant risk, we would already be dead.