Miscalculation Invalidates LHC Safety Assurances 684
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 The Oxford team say that roughly one in a thousand scientific papers have to be withdrawn because of errors but generously suppose that in particle physics, the rate is one in 10,000."
Voodoo Science (Score:5, Insightful)
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 [fairsoftware.net]
Re:Voodoo Science (Score:5, Funny)
"That isn't right" (Score:5, Interesting)
"It isn't even wrong..." [wikipedia.org]
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?
Uncertainty and certainty (Score:4, Insightful)
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).
Re:Uncertainty and certainty (Score:5, Funny)
How many times can we roll the dice before our luck runs out?
Every single time. After that, there won't be any more dice to roll, or anyone to roll them if they did exist.
If we had some dice, we could roll them, if we existed.
Fermi's principle (Score:3, Interesting)
Maybe the answer is that each had evolved to doing such physics experiments that their home planets all got chomped by black holes.
Re: (Score:3, Insightful)
Exactly. We rolled the dice once with the Manhattan Project. Before the first nuclear bomb was detonated, no one could prove with 100% certainty that the bomb would not ignite the entire planet's atmosphere. They could show that it was very unlikely to happen, but not impossible. So the dice were rolled and we got lucky. How many times can we roll the dice before our luck runs out?
When humans created the first man-made fire, nobody could prove with 100% certainty that the fire "would not ignite the entire planet's atmosphere".
An excerise in stating the bloody obvious (Score:5, Insightful)
Re:An excerise in stating the bloody obvious (Score:5, Funny)
Yes, yes, but what is it if I look inside the box?
Re: (Score:3, Interesting)
If they are correct, what are the chances they are wrong (or right)?
They are precisely equal to:
(1/1000)^N
where N is number of indpendent studies agreeing with the conclusion and having no contraditory ones.
For example, the ideas that the earth is round or that man evolved from apes or that smoking kills you is therefore not very well established since there are a lot of contradictory works that reduce that.
Re: (Score:3)
Consider yourself lucky you don't work with economists - climate science is positively heterodox in comparison. Seriously, it's borderline heresy to suggest that money is important, markets are inefficient, or that debt actually matters.
Re:Voodoo Science (Score:5, Funny)
Re:Voodoo Science (Score:5, Funny)
No need for that. You can subscribe to this RSS feed
http://www.hasthelhcdestroyedtheearth.com/rss.xml [hasthelhcd...eearth.com]
This is funny too
http://www.hasthelhcdestroyedtheearth.com/robots.txt [hasthelhcd...eearth.com]
Re:Voodoo Science (Score:5, Insightful)
This is voodoo science. And I don't mean the LHC experiments.
It's not science, it's just probability. It's senseless to try to assess any statistical estimates *themselves* based on Physics, just the probability that they could be wrong based on some very broad assumptions. Specifically, any estimate is arrived at by a chain (rather, DAG) of logic. What you CAN estimate is the probability that any Physics-oriented estimate is based on incorrect assumptions, by (presumably) analyzing that chain of reasoning down to first principles and assuming that a "logic error" might have been made at any point. I hope that the authors aren't taking it further than this, in which case, this is statistical masturbation.
Re:Voodoo Science (Score:5, Insightful)
Re:Voodoo Science (Score:5, Insightful)
Actually, this isn't that much voodoo.
It's just saying that, if someone has a 1/10,000 chance of being wrong, their assurance that there is a 1/1,000,000,000 chance of something isn't that good of a bet. In other words, if you want the latter level of certainty, you don't really have it, because of the fallibility of the research itself.
This is actually rather obvious. 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%. Or something like that.
Assuming his brother Jethro is just as bad (but uncorrelated) with him, then their dual recommendation that it will go flat only gets you 25.25% certainty, not 1% (or 0.01%). The numbers may not be exactly right (my stats are rusty), but you get the point.
Basically, they're saying that the research provides a wider error bound than it may claim, assuming that scientists uniformly make logical mistakes--which they very probably do.
The implication, then, is that the LHC estimates should be independently done by other teams. This is, well, the basis of the scientific method, so essentially this study provides a statistical analysis of what we already know--after enough work, science gets results. Of course, the base theories assumed by all of the researchers could be wrong, which would be unfortunate, but the LHC is going to nail that one pretty quickly. :)
This is not surprising, but not voodoo either.
Re:Voodoo Science (Score:4, Insightful)
Re:Voodoo Science (Score:5, Insightful)
If you took the ten seconds needed to read the abstract, you'd clearly see it's the former:
"... If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect. We develop this idea formally, explaining how it differs from the related distinctions of model and parameter uncertainty. Using the risk estimates from the Large Hadron Collider as a test case, we show how serious the problem can be when it comes to catastrophic risks and how best to address it."
In other words, since the upper bounds of a catastrophic outcome is a least the probability that they were wrong, it's important to estimate the missing factor.
Of course, the problem underlying this is the fact that if one _could_ calculate the missing factor, it wouldn't be an issue. In the case of the LHC, it is (probably :P) far more likely that the world would be destroyed by some yet-unknown physics (e.g. "the doctor" from Ender's Game) than by black holes. But, since it's impossible to predict the likelihood of something we don't know anything about, at some point one just has to throw the switch and see what happens.
Bad journalism, solid (enough) science. As always...
Re: (Score:3, Interesting)
If you took the ten seconds needed to read the abstract, you'd clearly see it's the former:
...
Bad journalism, solid (enough) science. As always...
My comments were based on the article and the summary rather than the abstract of the paper. Looking at the abstract it does appear to be an argument for formally factoring in something akin to a "chance we fucked something up somewhere" factor into the confidence of the prediction, with a particular emphasis on cases where the result of the event happening would be particularly bad.
So, yes, as you put it, bad journalism, solid (enough) science. I still take issue with the article (and summary) as they pa
Re:Voodoo Science (Score:5, Insightful)
This is patently ridiculous. If I write a relatively small piece of software where I have carried out a formal mathematical proof of the algorithms used in that software, I should obtain a much better bug ratio than the industry average, which includes work done by code monkeys working 90 hour work weeks.
Put another way, it's not clear to me that the statistical results for papers where an error might mean a measured loss of academic status are relevant to papers where the analysis regards the possible destruction of the Earth. So far the sample size on the latter is pretty small but the ones that have predicted the absence of global life-ending catastrophe have been 100% accurate. Of course they would have to be or we wouldn't be around to speculate about it, so we can't really make a conclusion from that either. But the point is that the foundation of this paper's statistical argument is itself invalid.
Re: (Score:3, Insightful)
In other words, since the upper bounds of a catastrophic outcome is a least the probability that they were wrong
It is not clear that this is the case. In fact: P(X)!=P(X|A)P(A)!+P(X|A)P(A) [from the actual article]. Your interpretation is only correct if the probablity that it goes is 100% if the assumptions are wrong.
Re:Voodoo Science (Score:5, Funny)
Yeah it is voodoo. If I calculate that there is a 1:10^20 chance an asteroid will destroy the earth this month, and someone else figures there is a 1:50 chance I am wrong, that does not make the odds of an asteroid destroying the earth 1:50. As wrong as the person calculating the odds are, the odds are still going to be incredibly small.
If what you were saying was true we could destroy the earth by having a 10 year old do the calculations since they would almost certainly be wrong.
Re:Voodoo Science (Score:5, Insightful)
Actually the point the article makes is not that there is a 1/1000 chance that the LHC will destroy the world but rather it is meaningless to say that the odds are as small as they safety reports etc say because the chance of the reports being wrong is greater than their predictions.
It basically boils down to saying that the scientists are saying there is a one in a billion chance that the LHC is dangerous then turning round and saying that there is a 1/1000 chance that that figure is wrong. Basically the point is that neither statistic is very helpful. Since the 2nd invalidates the first but tells you nothing about the actual probability of a dangerous event.
Re:Voodoo Science (Score:5, Funny)
I have calculated that there is almost no chance of money spontaneously raining out of the sky above me. However, I was drunk when I made those calculations, so they are most certainly wrong.
*waits expectantly*
Re:Voodoo Science (Score:4, Funny)
Welcome to slashdot, where an insightful post such as yours is moderated up as funny...
Re:Voodoo Science (Score:5, Insightful)
But for the LHC, arguably there is no accurate prior because nothing in that energy range has ever been done before
How many natural events involving hadrons in LHC+ energy ranges do you need?
99% of cosmic rays are made of hadrons (mostly protons and helium nuclei, but heavier nuclei are known), and they regularly collide with other objects made of hadrons (most of the mass of the visible universe) at LHC-plus energies.
Want me to worry about the LHC? Tell me when a cosmic ray collision has turned the Sun into a black hole or strange matter or new Big Bang or whatever your LHC disaster scenario is.
Don't fear the hadron (Score:3, Insightful)
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.
Re:Don't fear the hadron (Score:5, Insightful)
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.
Re: (Score:3)
The real problem here is the existence of a "black hole" boogeyman. It's not a singularity of compressed matter in peoples' minds, it's an invisible thing that will, regardless of size, slowly consume the entire earth. Stupid people, or uneducated ones, are the root cause of this hysteria.
Re: (Score:3, Informative)
To make a black hole out of a mass the size of the Earth, you need to pack it into a radius of about 9mm [wikipedia.org]. That's incredibly dense, even compared to all known metals. And for less massive blackholes, the required density increases; at the masses we're talking, the radius is miniscule. Black holes also tend to evaporate, with smaller black holes evaporating faster. So whether we are looking at the upper atmosphere or at the LHC, any blackholes created cannot swallow matter fast enough to survive, let alone
Re: (Score:3, Interesting)
I think you're right about the scales here, but only according to general relativity (in 4 dimensions), which also predicts that black holes of any sort will not form at the LHC. If they could, their radius would be about 10^-50 m, which is small compared to atomic distances (10^-10 m) or even nuclear distances (10^-15 m), and requires far greater energy densities than the LHC can produce.
The hope is that by observing the rapid evaporation of black holes at the LHC, one could support a class of theories th
Re:Voodoo Science (Score:5, Insightful)
But for the LHC, arguably there is no accurate prior because nothing in that energy range has ever been done before.
We are regularly bombarded with particles with 10^6 times more energy than the LHC produces. We can observe interactions much more intense than that in the visible universe.
Supposing all the scientists are wrong about their risk estimates, we should've observed the naturally occuring events at some point.
Meaningless Math (Score:3, Insightful)
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 kno
Frequency of outcome vs. degree of belief (Score:5, Insightful)
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.
Voodoo posting (Score:5, Insightful)
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.
Re:Voodoo posting (Score:4, Informative)
It could be as low as
Probability is not the same as maximum likelihood. Nor are either of them the same as knowing whether the event will actually happen or not. Probability is an estimate. Maximum likelihood is a worst-case estimate (in this case, where we define bad to be high probability). Knowing whether or not the thing actually happens is voodoo.
Re:Voodoo Science (Score:4, Insightful)
The implication, then, is that the LHC estimates should be independently done by other teams.
But how can they be independent? They'll be basing their arguments on the same laws of physics which apparently only have a 1 in 10,000 chance of being right. The HUGE flaw in their assumption is that the probability of a paper being wrong is a flat 0.01%. It is not. Some papers use conservative, well established physics (such as the LHC safety report) others are pushing the boundaries. The LHC safety report uses the simple fact that we do not see planets and stars disappear into Black Holes to set a limit on any danger the LHC poses. Could there be a mistake in the calculation of the actual probability - yes there could. But it cannot be significantly different because we do not see stars and planets disappear!
Re:Voodoo Science (Score:5, Insightful)
then you have to use the odds of them making a mistake as the probability of the event happening.
This isn't what the actual study states, though the summary seems to hint that way. To quote from one-of-the-FA's:
Which means we are left with the possibility that their argument is wrong which Ord reckons conservatively to be about 10^-4, meaning that out of a sample of 10,000 independent arguments of similar apparent merit, one would have a serious error.
Of course, this doesn't mean that the LHC is dangerous, only that there is no reasonable assurance of safety which, as Mark Buchanan writing in New Scientist this week says, is not the same thing at all.
To sum it up, they say that if a researcher predicts an occurrence rate for an event that is less than the researcher's own error rate, then the occurrence rate remains unknown ('cannot be assured')... not that it is equal to the researcher's error rate.
Re:Voodoo Science (Score:4, Funny)
Essentially their argument boils down to because people make mistakes and we can calculate the odds of them making a mistake, if they calculate the odds of something and it's greater than the odds of them having made a mistake then you have to use the odds of them making a mistake as the probability of the event happening.
Nuh-uh, that argument is solid and well formed.
Hey, I have another "scientific" theory, 1 out of every 460 scientific papers are about artificial intelligence, That means the LHC is alive and we don't even know it yet.!
Re: (Score:3, Funny)
You are wrong, it is not alive. It just emailed me and said that there was nothing to see here and keep moving along.
Re:Voodoo Science (Score:5, Insightful)
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.
Bias? Hype, maybe. Actually, this does make some sense, IMO. Say I was offering to shoot an apple off the top of your head and I told you I'd calculated there was only a 1 in 1 million chance of the bullet hitting you instead. Now if you knew (somehow) that there was a 1 in 10 chance I'd gotten the calculation wrong, you're going to look at it as more of a 1 in 10 chance of getting hit ... or at least way more than one in 1 million.
Re:Voodoo Science (Score:5, Insightful)
Re: (Score:3, Insightful)
Particle collisions happen in nature.
If we could that easily blink ourselves out of existence then we'd see planets disappearing all the time and black holes would be everywhere.
Re: (Score:3, Insightful)
Isn't this exactly the sort of physics that the LHC machine was designed to investigate? Higgs boson and particle mass, to be sure. That's what we always hear about, but it's more than that. The LHC will be brought up to full power gradually, over a series of incremental tests and experiments, over months and years, looking for anything unusual in the data, something we haven't anticipated. The data from those experiments can be examined for signs of black hole formation. If they do appear anywhere below LH
Re: (Score:3, Funny)
You almost had a good excuse for staying in bed there. "Sorry Boss. I can't come to work today because if I get out of bed I might destroy the planet."
Re:Voodoo Science (Score:4, Informative)
What the LHC does is slam hadrons -- large collections of quarks bound together by strong nuclear forces -- into other hadrons at high energy. The LHC uses the hadrons it does not because there is anything special about them but because it's somewhat easier to get the energies they want to study using the hadrons they choose. They also chose the energies they use for the collision for convenience more than anything special. Ideally, they want the most energetic range they can accurately control. If they could build a bigger collider, capable of higher energy collisions, they would, but these things are complicated, big, and expensive.
Cosmic rays are a mixture of fast particles, including hadrons of various sizes, traveling at very high speeds. Many cosmic rays are bare protons, the same as used in the LHC. The energy range of cosmic rays is wide, ranging to many more orders of magnitude higher than the LHC. A collision between a proton from space at 100TeV and a proton in an oxygen atom in the upper atmosphere of the earth is very similar to a proton-proton collision in the LHC, but much higher energy.
If I am interpreting a graph on Wikipedia correctly, cosmic rays with an energy of over 1000 TeV impact the Earth at a rate of about 1 per square meter per year. Given the size of the Earth, that's 14 million/second. So 14 million collisions hundreds of times more energetic than the LHC can do happen in the Earth's atmosphere every second. And there appears to be a power scaling going on. 10TeV cosmic rays are thousands of times more frequent than 1000TeV cosmic rays.
The difference, and why the LHC was built, is location. Looking at cosmic ray collisions tells us what the end result is going to be, but it doesn't tell us what happens partway through. If you look at a car crash on the side of the road, you know that the car got squished and the driver was injured. If you look at a car crash in a lab with cameras and crash dummies, you can tell that the driver hits the windshield before the crumplezones absorb all the energy.
The same sort of thing with the LHC. If the LHC will create Higgs Bosons, they are being created all the time in the upper atmosphere. But Higgs Bosons are expected to last an incredibly short amount of time, and all we see is what's left after they decay into other particles. We can't see cosmic ray collisions clearly enough to see if the decay particles come from Higgs or from other processes we understand well.
Re: (Score:3, Interesting)
The difference, and why the LHC was built, is location. Looking at cosmic ray collisions tells us what the end result is going to be, but it doesn't tell us what happens partway through. If you look at a car crash on the side of the road, you know that the car got squished and the driver was injured. If you look at a car crash in a lab with cameras and crash dummies, you can tell that the driver hits the windshield before the crumplezones absorb all the energy.
Yikes not the best slashdot car analogy I've ever seen.
How about, you want to study very high speed cars. On a daily basis people are caught by cops going over 100 mph all over the usa. But the odds of putting a camera up on any old street corner and seeing a 100 mph car are very low and at best you might see one in a zillion years. Like cosmic rays.
Or you could build a race track and have dozens of cars go just as fast whenever you want in front of all the cameras. Like the LHC.
Where my bad slashdot ca
Re: (Score:3, Interesting)
Not quite. Using your analogy, it's like you want to study the handling and aerodynamics of a car going 75. There are millions of cars on the road, but the best you can do to see cars going 75 on the public highwa
Re:Voodoo Science (Score:4, Funny)
> You don't say, "Oh well, we don't know for sure that anything bad will happen, so we'll just assume that it won't." That is voodoo science.
I say that to myself every time I put on my coat. I know I am lying to myself - with our limited understanding of the universe putting on clothes may very well trigger an unforseen event that destroys the solar system - but the snow outside has convinced me to sacrifice a little intellectual integrity in exchange for being able to wear my coat. Don't worry, I'm not taking too many risks: I'm not wearing anything underneath.
Re: (Score:3, Insightful)
A black hole can form in any region where the energy density is greater than a certain threshold (which is a function of the total energy involved). As the amount of energy (or mass) involved increases, the more relaxed this threshold becomes.
For example, if one were to fill the solar system with air (at sea level density, 1.2 kg/m^3) out to about 77 AU, it would be a black hole. For the Sun's mass to become a black hole, it would need to be much more dense, by about 15 million trillion times.
For the rela
Re:Voodoo Science (Score:4, Funny)
When it comes right down to it, though, the odds of creating a dangerous black hole is effectively zero, as evidenced by the fact that the various bodies of the solar system aren't black holes.
So what happened to the other 200 planets?
Are they good for anything? (Score:5, Interesting)
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.
Re:Are they good for anything? (Score:5, Interesting)
There is.
Matter being drawn into the black holes should be accelerated to damn close to the speed of light, and will emit massive amounts of gamma radiation, with a conversion rate that's higher than even fusion.
If we could harness the energy of the gamma emissions around artificial black holes, we'd be have vast energy generating capability, without the pesky fast neutrons that most fusion reactions generate.
Re:Are they good for anything? (Score:4, Funny)
Great. Now in a matter of years we'll have hippies protesting abuse of Nature's Own Black Holes for generating power. It's not really sustainable energy if all the mass you add to the hole extends its event horizon. (Does it?)
Re:Are they good for anything? (Score:4, Funny)
Just feed them the darkety kind and we'll never miss it.
Re: (Score:3, Informative)
From our perspective, the matter goes in. From the frame of the matter falling in, space-time is so warped that time starts to dilate really-really strongly as you approach a black hole.
Re:Are they good for anything? (Score:5, Insightful)
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.
Re:Are they good for anything? (Score:5, Funny)
Who would remember if we all died?
The race of intelligent beings who, millions of years from now, finds a small black hole orbiting a star, with a flag on its moon.
Honestly, if the human race has to end, that is exactly how I want us to go out.
Re: (Score:3, Interesting)
VNV Nation - Further lyrics (Score:4, Insightful)
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.
Re:Are they good for anything? (Score:5, Funny)
I'm fuzzy on the whole good/bad thing. What do you mean "bad"?
Re: (Score:3, Funny)
The real problems come in when aliens from outside our space-time continuum try to harvest their young in your warp core, thinking it's a natural gravity well! Time starts doing some whacky stuff!
Re: (Score:3, Interesting)
My first thought from reading this (Score:4, Interesting)
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.
Re:My first thought from reading this (Score:5, Funny)
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.
Re: (Score:3, Interesting)
Re:My first thought from reading this (Score:5, Funny)
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.
Re:My first thought from reading this (Score:5, Insightful)
> 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.
Re: (Score:3, Funny)
It makes me shiver just to think about it.
ObUserFriendly (Score:4, Funny)
From last Sunday [userfriendly.org]
Meh.... not really a problem (Score:5, Insightful)
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.
Re: (Score:3, Funny)
Comment removed (Score:3, Insightful)
Re: (Score:3, Informative)
Something here is flawed (Score:5, Informative)
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.
Re:Something here is flawed (Score:5, Informative)
This is dumb as shit. (Score:5, Insightful)
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!!!!
Bring it on! (Score:5, Funny)
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.
I call BS - RTFA - it's about probability, not LHC (Score:5, Informative)
~kulakovich
Well, the good news is (Score:4, Funny)
In the words of Dr Brian Cox (Score:5, Funny)
He's a particle physicist from my physics department (Manchester), and hence let it be known Oxford physicists are twats!
Re: (Score:3, Informative)
Heart of Gold (Score:5, Funny)
'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.
Sensationalist BS (Score:5, Insightful)
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.
Flawed, invalid, wrong, confused, or just nonsense (Score:5, Interesting)
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.
Of course (Score:5, Interesting)
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.
awesome logic (Score:5, Insightful)
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!
False claim (Score:4, Informative)
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.
TLDR: Article is a massive troll. (Score:5, Insightful)
Seriously, nothing to see here. This is truly an embarrassment to Slashdot (if that's even possible). Just move along.
Why I'm not worried (Score:5, Informative)
The Pierre Auger Observatory (http://www.auger.org/observatory/ [auger.org]) 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 day.... (Score:5, Informative)
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.
The real risk (Score:4, Insightful)
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.
Clarifications (Score:5, Informative)
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 [arxiv.org]
Re:Clarifications (Score:4, Interesting)
Okay, I've read the paper. I do not agree with it.
You claim that when a probability estimate for some event is very small, much smaller than the chance of the estimate being flawed, then we should consider the actual probability of the event to be larger.
In the papers terminology:
P(X) = P(X|A)P(A) + P(X|not A)P(not A)
Where given are:
- P(X|A) the probability estimate based on some argument and
- P(A) the chance that the argument is flawed
You then argue that if P(X|A) is very small, then P(X|not A), an arbitrary number, is probably much larger, and therefore P(X|not A) P(not A) may be significant compared to P(X|A)P(A). Thus, you argue, P(X) is probably higher than P(X|A).
This is where you go wrong.
You basically insert an arbitrary number, P(X|not A), based on an inexpert opinion, in the equation. Sure, the maths add up, you get a higher value for probability of the event, but your new probability estimate is no longer based on expert knowledge. You use some small number (1/1000) for P(X|not A) in your examples, but this makes no sense. Why not assume 50/50 if you simply don't know how likely it is that some event will happen? The main component of your new probability estimate is now only the statistical probability of an expert being wrong, which is independent of the probability of some event taking place.
In other words: you simply replace the estimate of an expert with the estimate of a lay person, multiplied by the change that the expert is wrong. However, even if the expert is wrong, that does not mean the lay person is right. The number you end up with is junk, it is meaningless. It should definitely not be used for risk assessment.
This is very dangerous use of probability theory. The argument in your paper is easy to follow, but it is false, and seeing that is not so simple. I sure hope no policy maker will read your paper and base important decisions on it.
If you live in the tail 2nd order terms matter (Score:4, Insightful)
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.
Re: (Score:3, Interesting)
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 pre
Re: (Score:3, Funny)
Re:A simple reason (Score:5, Informative)
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.
Re:A simple reason (Score:4, Funny)
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.
Re:hubris (Score:5, Informative)
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."