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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 The Oxford team say that roughly one in a thousand scientific papers have to be withdrawn because of errors but generously suppose that in particle physics, the rate is one in 10,000."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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Maybe I just like Romulans, but when I hear that the LHC will be making black holes I don't think about "woo, the earth is gunna get swallowed!" I wonder if there are any cool ways to use them for power generation.
How we know is more important than what we know.
"It isn't even wrong..."
What if they are so far off, that not only do they not produce black holes, they do nothing, but dim the lights in Switzerland?
"Flyin' in just a sweet place,
Never been known to fail..."
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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and I don't think it's the assurance that the LHC won't produce black holes that swallow the earth. There reason the whole LHC black hole rubbish is dismissed out of hand is simply because we have already obvesrved particles colliding with much higher energies than the LHC can produce and they didn't form black holes. Where did we observe these collions - in earth atmosphere. We built the LHC so that we could study the collisions in a controlled manner not because they are of particularl high energy.
I used to have a better sig but it broke.
I STILL don't think the LHC will kill us all but the fact we're debating it says something.
I don't know what you're trying to imply here.
People are still debating evolution.
Buckle your ROFL belt, we're in for some LOLs.
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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My retirement fund is pretty much crushed at this point.
Being consumed by black holes created by a multibillion dollar scientific whiz-ma-gig is sounding like a pretty good exit plan.
LHC is used as an example, misleading headline written by Fox News. -1
~kulakovich
"Anyone Who Thinks the LHC Will Destroy the World is a Twat"
He's a particle physicist from my physics department (Manchester), and hence let it be known Oxford physicists are twats!
'If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect,'
But if the improbability is large enough, and you hook it up to a nice, hot cup of tea; then we'll travel instantaneously through every point of the Universe, and possibly create a worried-looking whale and a bowl of petunias.
... and then they built the supercollider.
> 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.
If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect.
The headline says "Miscalculation Invalidates LHC Safety Assurances", yet the quote from the abstract seems to say that because arguments are sometimes "flawed" (terribly squishy word, that), it follows that for crucially important calculations we have to...well, the abstract doesn't say what we should do, and there's no link to the actual article. (Maybe there's a good reason for the latter.)
This amounts to the assertion that if an estimate is about something very important, then we can't trust the estimate, because some estimates are mistaken. In other words, we can't make estimates about important things—just trivial ones.
Unless someone produces the article in question, and unless it actually makes a more substantial argument than I quoted, I vote this a waste of my time on the part of whoever submitted it. May the rats eat your mail.
Great men are almost always bad men--Lord Acton's Corollary
The the safety of the LHC does not depend on a single calculation.
For a black hole created by the LHC to destroy the earth essentially requires everything we know about physics to be wrong.
First, can it even create them? The Standard Model says no - not even close. A certain category of String Theory models say maybe. This same models predict that these black holes are everywhere, being created all the time, even here on Earth.
Will black holes evaporate? They certainly should. If we are wrong about this than in all probability we are wrong about being able to create them at all as well - and we should hope we are, since they'd have swallowed up the universe by now if they were dangerous.
Is a stable micro black hole even dangerous? The numbers I've seen show a black hole like this would behave more or less like a neutrino. Maybe hitting an atom every few thousand or million years. The sun will enter its red giant stage, destroy Earth, and shrink down to a white dwarf before the black hole gains any significant mass. I don't think we will care much at that point.
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.
The LHC (http://en.wikipedia.org/wiki/Lhc) has a collison energy of in the TeV scale (tera = 10^12)
The Pierre Auger Observatory (http://www.auger.org/observatory/) records one 10^19 eV hit per km^2 a year, just on earth. If that hasn't turned up any major anomalies in our solar system or even in the major mass centers in our close vicinity over the billions of years it's been happening then I would like an explantion why.
Every single day the earth is bombarded with particles of far higher energy than those the LHC could ever come close to producing. We've observed cosmic rays with energies that are several orders of magnitude higher than the LHC can ever come close to producing. The Pierre-Auger project will probably reveal that we're hit by far more of them, and might even tell us where they're coming from. So if the LHC were capable of producing a world ending event, we already wouldn't be here. Sure, "scientists meddle with forces they don't understand" sells papers, (and let's face it, if we DID understand them, we wouldn't need to meddle) but we all do that. How many of you know exactly how the computer sitting on your desk works, down to the excitation states of silicon? Yet you still use them and don't worry about them causing the world to end, because you know that it just isn't possible. The same analysis works for the LHC.
If I had seen what they were doing beforehand I would have said 5:1 in favor. That place was a hell-hole.
Among other things the reactors had no containment vessels, was designed so badly that it required core cooling even after a shutdown. The control rods were so poorly designed that the core reaction rate actually increased while they were being inserted. The operators were performing a power failure test (on a live reactor!) where the steam turbines were to be used to generate electricity for the coolant pumps as they spun down. A previous similar test conducted under better conditions failed miserably. This previous failure was swept under the rug because it would have delayed commissioning the plant, meaning the plant's constructors would not get bonuses.
This new test was also planned in secret, without approval of the Soviet nuclear regulatory board.
During the run-up to this insane test a problem with the Kiev grid forced a delay in the test plan; rather than scrub and reschedule the plan was conducted with an unprepared night shift. The engineer in charge of operation of the control rods that night was a new employee with only 3 months of experience in that role. One of the documents associated with this disaster reads:
"One operator rings another and asks: What shall I do? In the programme there are instructions of what to do, and then a lot of things are crossed out. His interlocutor thought for a while and then replied: Follow the crossed out instructions."
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).
Except that even if the LHC did create a black hole, the effects on the earth or any people are basically nil. The amount of mass/energy that's going to be involved in the LHC is practically nothing compared to the black holes that astronomers are looking for out in space. If a black hole happened to be created in an LHC particle collision, it would be incredibly tiny. Smaller than an atom tiny.
A newer but reasonably well respected theory about black holes has them emitting "Hawking radiation", and one of the ways that this stuff works is that the smaller a black hole, the more quickly it radiates away its energy/mass, and a minuscule black hole like we're potentially talking about here would evaporate almost instantly. For more information about Hawking radiation, ask the internet.
Even if we assume that hawking radiation doesn't exist, and that black holes last forever, a minuscule black hole created by the LHC would not be particularly dangerous. First off, when you smash things together in an particle accelerator, the resulting particles usually end up moving very quickly. A black hole that happened to be created would likely be moving in a random direction at a speed well above escape velocity, and would quickly fly off into space and we'd never hear from it again.
But let's assume again that it just so works out that a black hole is created, doesn't evaporate, and it ends up with very little momentum, and just starts slowly drifting around inside the earth. The black hole would have very little mass, and it's gravity would be negligible, it wouldn't "suck" in matter. For it to absorb another particle, it would have to actually bump into it. It's important to understand how very tiny this black hole would be. The event horizon would be many times smaller than even the diameter of an atom. And although we generally consider matter to be reasonably solid and dense stuff, an atom is almost entirely empty space. The black hole could pass through billions and billions of atoms without actually hitting and absorbing a nucleus.
So worst case, we end up with an extremely tiny black hole hanging out around the center of the earth, and on rare occasions, happening to absorb a particle and increasing its mass a tiny bit. Perhaps many billions of years from now it will grow large enough that we might be able to detect it somehow, but it's more likely that the earth will have been destroyed by an expanding sun before then.
One time I threw a brick at a duck.
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?
As one of the authors of the paper in question, I'd like to point out that the headline and summary are very misleading. We have *not* identified any particular miscalculation and nor have we claimed to. Indeed, we are impressed by the recent safety report and agree that it is very unlikely that there will be a disaster.
The basic point of our paper is that what we really want to know is the chance of the disaster happening, but the reports give us the chance of it happening given a large number of physical assumptions. These probabilities are not the same, because there is a small but real chance that there is a flaw in these assumptions. This need not be due to any mistake on behalf of the physicists but may be like Lord Kelvin miscalculating the age of the Earth because nuclear fission and fusion were not yet known. Think of it this way: in a random sample of 1,000,000 cutting edge scientific articles that look as reliable as the LHC safety report, how many of them are likely to have flaws that invalidate their reasoning? This is especially pertinent as the safety report for the LHC's predecessor (the RHIC) failed to take into account anthropic considerations.
Of course even if the argument is flawed, we are still probably safe. We have indeed dealt with this point in the paper. The overall risk is very small, but larger than the raw calculations suggest, and non-negligible when there are 6.5 billion lives at stake. We thus urge caution and a reassessment of the safety of the LHC taking these considerations into account.
I encourage you all to read the actual article, which goes into many of these points in detail:
http://arxiv.org/pdf/0810.5515v1
I am sorry, The THEORY of evolution and the THEORY of creation both imply that I am somehow related to the people who make LOL cats and I just can not accept that. I CAN NOT accept that.
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.