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 The Oxford team say that roughly one in a thousand scientific papers have to be withdrawn because of errors but generously suppose that in particle physics, the rate is one in 10,000."
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.
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.
"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?
Re:Voodoo Science (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:Are they good for anything? (Score:2, Interesting)
true - but if you have a stable black hole you risk the chance of losing containment... which could be bad...
If you have an unstable black hole you risk not feeding it enough and having it evaporate, or feeding it too much and having it become stable. If it evaporates you have to dedicate significant energy to getting another one going. I don't know what the energy balance would look like, but I'd think constantly having to pop new black holes would significantly decrease the effective conversion rate.
If we had space ships in non-earth orbit, it would be a great idea, I'd rather not try to make a stable black hole that could collide with earth.
Re:My first thought from reading this (Score:2, Interesting)
With Iran having secured the technologies to enrich uranium for manufacturing nukes, I dare say the probability of a nuclear world war wiping out humanity is a hell of a lot more likely than the LHC destroying the planet.
Re:Red Title? (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 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.
Damn it... (Score:2, Interesting)
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)
Re:This is dumb as shit. (Score:2, Interesting)
Mm.. I don't want to sound like a troll, and definitely not to give my support to TFA, but the opponent in your rhetorical argument actually brings up a good point. "But you could be wrong" should always be considered. The current financial crisis came about, in part, because of not enough people with a lot of money thought (or cared...) to ask "but what if I'm/we're/they're wrong?".
Of course I don't mean that the LHC should shut down or any number of risky scientific endeavors should not be undertaken; the benefits almost certainly outweigh the risks. And I certainly have no idea whether the calculations done to show the LHC is safe or unsafe were rigorously done. I'm just pointing out that, hey, doubt and questioning have their place in rigorous science and shouldn't always be brushed away as fear and ignorance by the masses. Even scientists can get caught up in their own enthusiasm for a project.
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.
Re:Are they good for anything? (Score:3, Interesting)
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.
Re:My first thought from reading this (Score:3, Interesting)
Re:Voodoo Science (Score:2, Interesting)
Even the LHC experiments are voodoo science. The only way they will truly know what will happen is to turn the thing on and observe what happens.
Mathematical formulas on paper are all well and nice, but most science relies on actually performing the experiment. But, we are talking about the possibility of creating a black hole here on earth. A black hole has never existed on earth before so no one can say exactly what will happen.
Let's say for argument sake I build a modified revolver. Only instead of having 6 chambers it has 6000 chambers. I load one round into a chamber, give it a spin and close it. Once closed it cannot be opened to observe where the round is in relation to the hammer. I then hand you some mathematical studies done by leading scientists on the probability of the round being fired if I pull the trigger. Would you let me point the barrel at your head while I pull the trigger?
What if the same scientists came out later and said their initial calculations were wrong, here are the new calculations and the odds of the round firing now favored you less. Would you let me point the barrel at your head while I pull the trigger?
What if another, separate, group of scientists came out with a study that said exactly what is in the above article? "If the probability estimate given by an argument is dwarfed by the chance that the argument itself is flawed, then the estimate is suspect." Would you let me point the barrel at your head while I pull the trigger?
Maybe if I pull the trigger nothing will happen and you can walk away. Maybe if they turn on the LHC nothing unexpected will happen and the earth will go on revolving around the sun. But then again, maybe the round will fire and you die. And maybe the LHC will produce a black hole that ignores their scientific calculations and begins swallowing everything in its path.
Idiotic Arxiv papers (Score:1, Interesting)
Can /. stop linking to papers on the Arxiv. Any one can publish ANYTHING on the Arxiv. It is not a reputable scientific source and /. should stop treating like one.
Re:Voodoo Science (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 paint a completely different picture from the one in the abstract, so I still say the article is bunk, but the paper itself seems ok enough.
Re:Voodoo Science (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 car analogy breaks down is the very rare cosmic ray / cars, when you can actually find one, are going way way way faster than anything we could build in an accelerator / racetrack.
So, you want single events at super high energy, go cosmic rays.
You want zillions of collisions at quite pedestrian energies, go accelerator.
Kind of like high voltage vs high current.
Re:Voodoo Science (Score:2, Interesting)
... based on incorrect assumptions,...
One underlying assumption is that there is no God that ultimately owns, and controls this universe and everything in it, including a physics experiment by His creatures. That is ultimately the question, not whether some theorized black hole will bring the "end of the world". The underlying assumption of all the speculation here is that man is the master of his fate, the captain of spaceship Earth.
If the underlying assumption (belief) is that there is indeed a God who in control, then there is nothing to worry about. When He decides to pull that switch, there is nothing anybody can do. I seriously doubt that the LHC is the switch and that man can or will pull the switch that ushers in the end of this planet and everything on it.
Re:Voodoo Science (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 highways is via road-side cameras, 100 feet away from the road, and you don't know when the cars are going to drive by, and they could be doing anything from 60 to 120mph and you don't know what in advance. One time one of your colleagues saw a car zip past at 300mph, but it hasn't happened again. You see 75mph cars all the time, but your pictures are not all that good.
However, on the track you can set up an observing station that is 10 feet wide, has pressure and strain sensors embedded in the roadbed, has air pressure meters at close intervals, has high-speed, high resolution video recording from both sides, above, below, and at various angles. And you know, to the fraction of a second, when a car is going to go through your sensor. And you have dozens of expert drivers who send a car through the observing station at 30 second intervals at exactly 75mph.
The hundreds of inexpensive road-side cameras you and your colleagues have deployed see more cars doing 75+ than you will see on your track, but you know much more about how the cars handle from your data.
Re:Are they good for anything? (Score:3, Interesting)
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.
Re:Don't fear the hadron (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 that predict "large" extra dimensions. I'm not sure if this is exclusive to string theory or not, but I think the basic idea is that if the universe is really 10-dimensional or so (which seems to be a general requirement of any string theory), the "extra" (not observed) dimensions must be somehow curled up in such a way that they have no affect on any observed phenomena. Large Extra Dimensions is the idea that some of these may not be curled up so tightly, and would give rise to new physics on very small scales. It would then be possible for microscopic black holes to be many orders of magnitude larger than one would expect otherwise, and possibly even within reach of whatever energy scale the latest accelerator is running at.
As I describe it here, this theory seems rather far-fetched. It is a weakly-motivated extension of string theory, and all string theory has going for it right now is a peculiar aesthetic. But I'm sure I'm not doing it enough justice. I think Large Extra Dimensions is an attractive theory because it helps resolve quite a few problems of consistency and scale (or "naturalness") in more standard theories. But why the scale of these extra dimensions should be just enough so that we could start to see effects of it at the LHC and not at even higher energies is particularly hard to justify.
So seeing black holes at the LHC seems extremely unlikely, but it's worth looking for them because the importance of such a discovery would be huge.
Then there's the problem of whether or not these black holes could somehow rapidly grow (not evaporate) and shrink the earth down to the size of a marble. Well, I'd think that if this were the case, we'd probably have seen "harmless" black holes at lower energies already, such as at RHIC. They looked, but found nothing. And then there's the cosmic ray argument that others have mentioned here. Cosmic ray collisions at energies at (and way beyond) the LHC energies have been occurring all the time, and at rates much higher than the LHC as well. I think there are lots of observations that prove our universe is not so delicate.
It sounds to me like the article referenced does not take into account any kind of far-fetchedness of a doomsday theory. Maybe we're living in a matrix-like virtual world and with just the wrong combination of words typed into my computer, or the wrong set of thoughts in my mind, I'd expose a new bug in The Simulator and crash it, destroying all life as we know it. There is a lot of uncertainty in this theory. Does that mean we must live in constant fear? If we must, there are better things to worry about. So for me this "Probing the Improbable" article fails to pass a sanity test.
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.