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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 The Oxford team say that roughly one in a thousand scientific papers have to be withdrawn because of errors but generously suppose that in particle physics, the rate is one in 10,000."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.
--
The 5 Steps to a Great Startup Idea
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.
...that these researchers are wrong about the probability that the other researchers are wrong?
My first thought from reading the summary is that essentially we're at a point in technology or whatever that we could, POSSIBLY, destroy the planet in a literal sense. That's a scary thought, especially if you think what we'll be capable in a hundred years from now.
I STILL don't think the LHC will kill us all but the fact we're debating it says something.
From last Sunday
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
"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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Means that there is a much greater than zero probability? Sorry, either the paper is wrong or your interpretation of it is wrong. Publishing a probability is not a determination of that probability.
There is no published figure regarding the probability of your computer turning into chocolate pudding before it reaches warranty. The probability is still approximately zero despite that.
The probability of a black hole at the LHC swallowing the Earth is approximately zero, and it doesn't matter how many sensationalist journalists try to misconstrue real science in an effort to drum up sales.
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.
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.
Editors: Would somebody PLEASE create a FAQ on this? A red title thread has been in several articles every day.
Answer: A red title is what appears on articles subscribers see in "The Mysterious Future!" previews. For some reason, as an article is taken out of "The Mysterious Future!", the flag that makes the article a subscriber-only preview seems to come off some period of time ahead of the flag that makes the title red, so what you are seeing is what subscribers see when the article is in subscriber preview mode.
Either they did this on purpose to indicate that the article is 'hot off the presses' or there's some sort of race condition in their new styling code.
My blog
LHC is used as an example, misleading headline written by Fox News. -1
~kulakovich
That this would be the end of the world that neo-cons hope and pray for. Now, they will not have to see a black president in for long, nor take responsibility for their actions.
I prefer the "u" in honour as it seems to be missing these days.
"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.
What were the experts' odds on Chernobyl?
How did this crap manage to find Slashdot?
I saw this either this week or last with some idiots moaning about it.
There are equations for working this crap out, and unless they REALLY screwed up with everything we currently know about physics, i have a very good feeling that we won't be ripped atom-from-atom.
The blackhole won't be able to gather anywhere near enough mass within our stars lifetime, IF one is even created in the first place.
By the time this is even a threat, humans have either:
1) died
2) died
3) ????
4) died.
Actually, wait a minute, wasn't something similar on HERE a few days back about it?
It was either here, CNET or Current, and i highly doubt it was Current... (no offence)
But what if we don't die? What if we discover that we've been living in a black hole this whole time and the current universe's edges are simply the expanding event horizon? Living in a black hole within a black hole would be neat! I wanna press the red button :(
www.isoHunt.com
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.
I prefer to rely on http://www.hasthelargehadroncolliderdestroyedtheworldyet.com/
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?
If Jimbo tells you that there's a 1% chance that your tire will go flat if you don't fix it, that's not 1% if Jimbo is wrong 50% of the time. At best, it's 50.5%.
But you assume that Jimbo's being wrong means that the probability of failure is 100%! It's not necessarily. In fact, Jimbo might be wrong in that the probability of a flat tire is actually 0% -- in which case, his being wrong has helped you. If this is the case, then the total probability is 0.5%, much better than 1%. This is the best case; 50.5% is the worst case, and neither is "more likely", because we don't know what the conditional probabilities are. It's this fallacious reasoning -- that if the theory is wrong, the probability of the event must be greater -- that make this article technically true, but useless. We cannot handpick these probabilities. From the TFA (not the abstract):
The other unknown term in equation (1), P(X|not A) [read: the probability of the catastrophe given we're wrong], is generally even more difficult to evaluate, but lets suppose that in the current example, we think it highly unlikely that the event will occur even if the argument is not sound, and that we also treat this probability as one in a thousand.
(emphasis and comment mine). I disagree. This probability is impossible to evaluate, and so this paper means nothing.
The LHC paper has been 'published'. It has been peer reviewed up the butt. It has not been withdrawn. It obviously then falls into the 'other' 999/1000. Like slashdot is fond of saying: there is nothing to see here, move along.
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 CERN leaves the window open long enough by failing to produce real collisions in the LHC that don't destroy the planet the alarmists WILL achieve their goals and get it shut down. Have no doubt. Politicians of all stripes thrive on alarmist nonsense. This 'story' is exactly the sort of double-speak that can lend just enough credibility to the alarmist argument to get the ball rolling.
Lurking at the bottom of the gravity well, getting old
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?
A black hole CAN NOT BE CREATED By US!!! Even if several thousand atome worth of matter were smashed together into an area one millionth of an atomic nucleus, one thousand atoms worth of gravity doesn't amount to anything in the scale of the real world. even if these atoms stayed in that configuration for many seconds or minutes, they still don't have enough mass to create gravity that could start pulling in other matter, especially since the collisions are set-up in a very high vacume and all the surrounding matter (sensors etc.) are bolted very tightly to a very sturdy base. The fact that people continue to debate this issue just astounds me. A tiny bit of concentrated matter is still only a tiny bit of matter, no matter how much you consentrate it! Remember, a true black hole has the mass of a star in an area the size of a single atomic nucleus, so that's some pretty consentrated mass. You can hang a lead ball on a 2000 foot string next to a granite mountain face and only barely detect the deflection of the ball on the string. Gravity is a very weak force people.
Keep passing the open windows...
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
Along with the other comments here, I would also like to point out that arXiv is _not_ peer reviewed. It's really frustrating the amount of citations from arXiv I've seen lately. People need to take everything from arXiv with a grain of salt. Sure, arXiv is there to spark discussion, but until it ends up in a peer reviewed journal, treat it as hearsay.
Who would remember if we all died?
At the end of days, at the end of time.
When the Sun burns out will any of this matter.
Who will be there to remember who we were?
Who will be there to know that any of this had meaning for us?
And in retrospect I'll say we've done no wrong.
Who are we to judge what is right and what has purpose for us?
With designs upon ourselves to do no wrong,
running wild unaware of what might come of us.
The Sun was born, so it shall die, so only shadows comfort me.
I know in darkness I will find you giving up inside like me.
Each day shall end as it begins and though you're far away from me
I know in darkness I will find you giving up inside like me
Without a thought I will see everything eternal,
forget that once we were just dust from heavens fire.
As we were forged we shall return, perhaps some day.
I will remember you and wonder who we were.
Are you really sure about this? I've played Katamari Damacy and a small little ball starting at less than 1 cm, bumps into random things thus growing in size. Eventually, the ball is able to roll over and absorb the earth, other planets, stars and other galaxies and (presumably black holes). What's left after I don't know - it was an computer-based physics simulation played on my television screen.
Basically all the arguments for black hole creation fail when you ask the question, "Where are you going to get all the mass to create the black hole?"
A black hole has much more mass than our planet. Energy released from the destruction of mass is supposed to be very large; even if it were possible to convert energy into mass at the LHC, the mass gain should be negligible.
The headline and summary are misleading but the main point of the paper stands. Once we are talking about probabilities of one-in-a-million or less, other second order terms come into effect.
Example: the probability of the blood "not being from OJ Simpson" was declared to be "one-in-six-billion". Well at those orders of magnitude the probability of an unknown-to-him twin brother are higher than that. Of course I'm not claiming he has one. In all likelihood he doesn't, it's just that the probability of that event is around 1-in-100 million, which far outweighs the 1-in-6,000,000,000 given by the genetics "expert".
So the correct thing to say is that the chances of the blood not being OJs is one-in-100,000,000. Good enough for me to convict and scientifically accurate. The other figure is nonsense.
Maybe the answer is that each had evolved to doing such physics experiments that their home planets all got chomped by black holes.