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Princeton Student Finds Bug In LHC Experiment 243

Posted by ScuttleMonkey
from the peer-review dept.
An anonymous reader writes "A Princeton senior has found a bug in the hardware design for the Compact Muon Solenoid (CMS) experiment of the Large Hadron Collider (LHC). In the hardware used to record and capture events in the LHC, she discovered errors that were leading to the appearances of double images because of particle streams known as jets. 'Xiaohang Quan '09 was working on her senior thesis when she found a miscalculation in the hardware of the world's largest particle accelerator. Quan, a physics concentrator, traveled to Geneva, Switzerland, last week with physics professors Christopher Tully GS '98, Jim Olsen and Daniel Marlow for the annual meeting of the European Organization for Nuclear Research (CERN). This year, however, they also came to discuss Quan's discovery with the designers of the hardware for the Compact Muon Solenoid (CMS) experiment, which, as part of the Large Hadron Collider, has the potential to revolutionize particle physics.'"
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Princeton Student Finds Bug In LHC Experiment

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  • wha? (Score:4, Funny)

    by Lord Ender (156273) on Monday March 23, 2009 @05:11PM (#27303775) Homepage

    Her last name is "09" and she is a "concentrator?" Who wrote this?

    • Re:wha? (Score:4, Informative)

      by scheme (19778) on Monday March 23, 2009 @05:14PM (#27303821)

      Her last name is "09" and she is a "concentrator?" Who wrote this?

      It's from a student newspaper. Hence the 09 which refers to her graduation year. Also the concentrator part means that she's concentrating on physics. Some universities call it concentrating on a subject rather than majoring.

      • by hellfire (86129) <deviladv@PASCALgmail.com minus language> on Monday March 23, 2009 @05:33PM (#27304097) Homepage

        Some universities call it concentrating on a subject rather than majoring.

        That's because years ago, teachers found out most students don't concentrate on anything.

        But this girl is definitely the exception, she's obviously concentrating very hard.

        • Re: (Score:3, Funny)

          I've found thousands of bugs... Why aren't anyone writing stories about me? ;(

          • Re:A concentrator! (Score:4, Insightful)

            by icebraining (1313345) on Monday March 23, 2009 @06:09PM (#27304495) Homepage

            Have you found thousands of bugs on billion dollar projects announced by the media as world-sucking black-hole producing machine?

            • by bucky0 (229117)

              I have found a handful on the CMS experiment. While the physics and actual hardware is solid, the computer side of it is written a lot by grad students and others without any formal CS training. Bugs pop up.

              • Re:A concentrator! (Score:5, Insightful)

                by sortius_nod (1080919) on Monday March 23, 2009 @08:39PM (#27306311) Homepage

                ...the computer side of it is written a lot by grad students and others without any formal CS training. Bugs pop up.

                I really don't think that's a valid statement. Bugs pop up in anything, CS trained or not. In fact, some of the best coders I've come across have been untrained.

                Arrogance like that is a reason why there are bugs in programs...

            • by Walkingshark (711886) on Monday March 23, 2009 @09:27PM (#27306747) Homepage

              Have you found thousands of bugs on billion dollar projects announced by the media as world-sucking black-hole producing machine?

              I found some bugs in Tim Geitner's bailout plan, which seems to match the second part of your criteria...

      • Re:wha? (Score:5, Funny)

        by Red Flayer (890720) on Monday March 23, 2009 @05:42PM (#27304193) Journal

        Also the concentrator part means that she's concentrating on physics. Some universities call it concentrating on a subject rather than majoring.

        What a load of horsecrap. Do you even go to Princeton?

        At Princeton, students are labeled by their preferred method of problem-solving.

        Some students are "blackboardists" (though this label is being phased out for a more color-neutral label, since some students use whiteboards. Also something about racism. "Vertical writing surfacist" is just unwieldy, I think they'll settle on "writist".) Some students are modelers -- but these tend to be chemists.

        This student is a concentrator, a la Feinman.

        When asked how Feinman would solve a specific theoretical physics problem, a famous physicist (I can't recall who it was), said, "He'd close his eyes for a minute or two, then write the solution on the blackboard."

        At any rate, I'm very surprised a concentrator was able to find a hardware problem. Ususally concentrators don't bother with hardware, since the solution comes directly from their wetware.

        Just to note, that there are other types of problem-solvers at Princeton as well, but they are not as common in the Physics department. In the Fine Arts, one finds "Lysergicists", in Liberal Arts one finds "Inhalors". Most dropouts are "Procrastinists", and if one is very luck, you can spot an "Osmosisist" on the green -- you can tell them from others by the fact that they always carry their books on their head.

        • Re: (Score:3, Funny)

          by dgatwood (11270)

          ...in Liberal Arts one finds "Inhalors".

          Where I come from, they're called potheads.

          • Re: (Score:3, Funny)

            by Red Flayer (890720)
            I think the label is meant to be inclusive. We wouldn't want to leave out the painthuffers and methsmokers, would we?
        • by jra (5600)

          You should have left off the Tolkein quote; even I wouldn't have been sure, then...

        • by fractoid (1076465)

          Some students are modelers -- but these tend to be chemists.

          I thought Psych and CogSci students were more likely to be modelers... at least she claimed it was "modelling". I thought modelling required more clothes and less dancing but what would I know?

          Just to note, that there are other types of problem-solvers at Princeton as well, but they are not as common in the Physics department. In the Fine Arts, one finds "Lysergicists", in Liberal Arts one finds "Inhalors". Most dropouts are "Procrastinists", and if one is very luck, you can spot an "Osmosisist" on the green -- you can tell them from others by the fact that they always carry their books on their head.

          Pure gold, 10/10.

    • Re:wha? (Score:5, Funny)

      by Anonymous Coward on Monday March 23, 2009 @05:15PM (#27303837)

      That's her model number. She's actually a Japanese Robot.

    • Re:wha? (Score:5, Informative)

      by Quothz (683368) on Monday March 23, 2009 @05:18PM (#27303887) Journal

      Her last name is "09" and she is a "concentrator?"

      That threw me, too. The '09 appears to be standard form for the Princetonian, representing her (expected) graduation year.

      Who wrote this?

      Tasnim Shamma

      Personal Info

      * Degree: A.B. in English, IPS in Journalism

      * Hometown: Jamaica, NY

      * Contact Email: tasnim.shamma@gmail.com

      Personal Bio

      Princeton '11, Brooklyn Technical High School '07, Daily Princetonian news/blog/multimedia staff, Orange Key tour guide, Daily Princetonian Class of 2001 Summer Journalism Program Alum'06/ Program Staff Associate '08 (www.princeton.edu/sjp), Aspiring Reporter (if there are jobs left when I graduate) ;)

      Off topic: Miss Quan is cute.

      • Re:wha? (Score:5, Funny)

        by Anonymous Coward on Monday March 23, 2009 @05:30PM (#27304061)

        Off topic: Miss Quan is cute.

        Funny how the site got slashdotted right after your comment appeared.

      • by jra (5600)

        It's not just Princeton. Every college publication I've ever seen mentions the grad year after a student's name, at least on first reference.

        And she's not bad. But if I understand Chinese naming properly, Quan is her given name, not her surname.

        • AIUI many Chinese flip the name order around when they come to the States, because that's how it's done here. Or at least they put it into the expected order when talking to white people. And if her family has been here for a few generations, which is hardly unheard of, she's probably just been raised to put the surname last. I don't really care enough to go find out which name is which for Ms. Quan.
        • by Quothz (683368)

          But if I understand Chinese naming properly, Quan is her given name, not her surname.

          That's a good point, except that "Quan" is a surname and "Xiaohang" is a given name. It's a pretty safe assumption that this is the case here, much like assuming the name "Stephanie" is given or the name "Miller" is a family name.

    • Re: (Score:3, Informative)

      by edittard (805475)

      Pity the "anonymous reader" didn't go the extra nine yards and become an invisible writer. Then we'd never have known what a waste of oxygen he was.

    • by treeves (963993)
      Clearly she concentrated very hard in order to find this error...
    • Re: (Score:3, Funny)

      by mcgrew (92797)

      Her last name is "09" and she is a "concentrator?" Who wrote this?

      Seven of nine.

  • Guess LHC better get in for a checkup. Like so many major observatories of late, this one is also near-sighted. ^_^

    • by peragrin (659227)

      at this rate someone had better double check the James Web before it takes off for orbit.

  • then it goes from a bug to a systematic error, which can likly be accounted for when it comes to results
    • by Gromius (677157)
      yeah its just an algorithm bug (having just checked this out), its no biggy at all. Its good that its fixed but CMS (and other particle detectors) are very impressive peices of kit which are very difficult to understand. It takes hundreds of scientists years to fully understand such a detector, continously making small improvements such as this. Its good and it clearly shows she has the smarts to do a PhD but its not exactly the earthshattering stuff the article makes out.
  • Great story. (Score:5, Insightful)

    by palegray.net (1195047) <{philip.paradis} {at} {palegray.net}> on Monday March 23, 2009 @05:13PM (#27303807) Homepage Journal
    She just made her career, and rightfully so.
    • Re:Great story. (Score:5, Informative)

      by Gromius (677157) on Monday March 23, 2009 @05:45PM (#27304221)
      Its not actually amazingly impressive, its made to sound a lot more impressive than it actually is. One the meeting in question was "CMS week", one of several weeks a year we get all our collaborators together at CERN not CERNs annual meeting. She's basically improved our jet algorithm (as far as I can tell, the article is woefully lacking in details), a decent job for an undergraduate and will certainly help her walk into a PhD place as a shes clearly good enough but she's certainly not the only undergradute to have made a contribution such as this.
      • How do these undergraduates access the LHC hardware schematics? I'd like to poke through them, if only to gape.
      • Re: (Score:3, Funny)

        by Walkingshark (711886)

        but she's certainly not the only undergradute to have made a contribution such as this.

        Woah woah woah there. Didn't anyone tell you undergraduates aren't good for anything and undergraduate degrees are only useful to show you can "complete something?" Get with the latest talking points there please.

    • by couchslug (175151)

      "She just made her career, and rightfully so."

      Yeah, but is she hawt?

      • I have always had a high preference for nerdy girls. The fact that she's attending Princeton for physics is enough to raise my pulse.

        Incidentally, my girlfriend falls squarely in the category of "hot nerd." They're really hard to find, owing to their tendency to be fairly reclusive. I got lucky with her :). Hope she doesn't read this comment (at least the first part)...
      • To more directly address your question, the article features her picture [dailyprincetonian.com]. Personal preferences may very, but my answer is "yes."
  • by MadMidnightBomber (894759) on Monday March 23, 2009 @05:14PM (#27303825)

    if it moves, it's biology. If it doesn't work, it's physics.

  • by kop (122772) on Monday March 23, 2009 @05:15PM (#27303845)

    They are calling her "Gordon" and are scheming to get her to be the guinea pig in the resonance cascade scenario test.

  • It's quite clear that these issues will never cease. This is simply the result of the Universe preventing a causality paradox. If the LHC were turned on (Let there be light!) then existence as we know it shall cease to exist.

    Oh yeah, I went there.

    • Re: (Score:2, Funny)

      by Slumdog (1460213)
      I think you want to say that if the answer was found, the universe would cease to exist and be replaced with something even more inexplicable.
  • by bigredradio (631970) on Monday March 23, 2009 @05:19PM (#27303911) Homepage Journal

    I would have to say that this student will not have a problem finding a job after graduation.

    CERN: Now Xiaohang, Sherry is going to show you around the place. She can answer any questions you might have about fringe benefits or dress codes or anything and I'll see you back upstairs when you're done, okay? Sherry, take good care of this young lady. She's one of the ten finest minds kin the country.

    XIAOHANG: Someday I hope to be two of them.

  • Not a hardware bug (Score:5, Informative)

    by rminsk (831757) on Monday March 23, 2009 @05:22PM (#27303935)

    A Princeton senior has found a bug in the hardware design for the Compact Muon Solenoid (CMS) experiment of the Large Hadron Collider (LHC).

    The bug was in the algorithm analyzing at the data from the CMS and not the hardware.

    • by Anonymous Coward on Monday March 23, 2009 @06:36PM (#27304841)

      Actually, not a bug at all. It's a design choice.

      The CMS Global Calorimeter Trigger hardware uses a 3*3 sliding window algorithm to find local maxima (jets) in the calorimeter regions. These 3*3 windows can partially overlap, meaning some energy is double-counted. Having a small amount of double-counted energy has no real consequence on the validity of the triggering, but does greatly simplify the firmware.

  • Yes, it's probably sexist to say it but women have some innate ability to debug code. I've seen this happen too much professionally to think of it as a trend. The evolutionary origins? I can't explain.
    • I believe finding and removing bugs from their offspring's fur has been a longstanding job for mothers.

    • by hobbit (5915) on Monday March 23, 2009 @05:59PM (#27304365)

      I've seen this happen too much professionally to think of it as a trend.

      I've seen this sort of anecdotal nonsense too much on Slashdot to think of it as statistically significant.

    • by Locke2005 (849178)
      Yeah, but they are terrible at estimating distances... probably because they keep getting told that this much (holds 2 fingers apart) is six inches!

      Oh, and judging from my wife, they're not really good at debugging, they just take great pleasure in pointing out mistakes made by men...

  • by Anonymous Coward on Monday March 23, 2009 @05:37PM (#27304137)

    via hardware verification with ACL2 [utexas.edu].

    I hope this helps the LHC Experiment so it doesn't cause
    a black hole to destroy THE UNIVERSE.

    Yours In Physics,
    Kilgore Trout

    • Re: (Score:2, Interesting)

      by ekhben (628371)

      I'm sorry to be the one to tell you that there's already black holes slowly destroying THE UNIVERSE. They're going to the whole thing eventually; there's a giant one busily destroying THE GALAXY right now. Maybe you're more concerned with the microscopically small part of THE UNIVERSE that is necessary to sustain your own life?

      Yours in Pedantry,
      Ekhben

  • This is awesome (Score:5, Insightful)

    by adpe (805723) on Monday March 23, 2009 @05:43PM (#27304209)
    This story makes me fall in love with science even more. Smart people think of ways to understand the world better, other smart people review it, find errors and discuss their finding with other scientists.
    They have a discussion like adults, they look at the math, one side is correct and they correct their experiment and thank them for the contribution.
    This is what the world is supposed to be like. Not like these fucking religois nutjobs, screaming at each other, arguning who has the cooler imaginary friend, without having even a halfway decent argument. They're just like "You're stupid!". "No, you are!". "No you!"
    Science for the fucking win!
    • Re:This is awesome (Score:5, Interesting)

      by rhizome (115711) on Monday March 23, 2009 @06:01PM (#27304383) Homepage Journal

      Smart people think of ways to understand the world better, other smart people review it, find errors and discuss their finding with other scientists.

      Absolutely. I'd be curious to know whether anything like this has ever happened in the world of Intelligent Design or any other theological science disciplines. "Regent University Senior find new method by which God created the universe!"

      • Re: (Score:2, Interesting)

        by Terwin (412356)

        I don't know about ID, but if you want a cleric and a scientist, try St. Albert the Great [newadvent.org]
        Before my last move I attended a Catholic church named after him. The quote up on the wall was 'Use all the wisdom of man to delve the mysteries of God'

        I expect he would be really excited about the LHC if he was alive today.

      • Re:This is awesome (Score:4, Interesting)

        by Gotenosente (1496667) on Monday March 23, 2009 @06:56PM (#27305089)

        Absolutely. I'd be curious to know whether anything like this has ever happened in the world of Intelligent Design or any other theological science disciplines. "Regent University Senior find new method by which God created the universe!"

        Actually ancient Indian spiritual literature is filled with accounts of various spiritual leaders debating each other. Often times, if one lost the debate they'd have to study under their victor. It was during this era that one of the world's great international universities, Nalanda [wikipedia.org], was created. Later it was burned to the ground by invading Muslims.

    • Re:This is awesome (Score:5, Insightful)

      by Mr. McGibby (41471) on Monday March 23, 2009 @06:14PM (#27304539) Homepage Journal

      Yup. Scientists never argue or deride the work of their colleagues without merit. Never.

      In case you missed it, I'm being facetious. Irrational disagreements and other immature behavior are a human problem. The scientific community is no less guilty of this than anyone else.

      • Re:This is awesome (Score:4, Insightful)

        by Godji (957148) on Monday March 23, 2009 @06:33PM (#27304793) Homepage
        Yes, but in said community counterarguments like "Here's the math and it works out, while your doesn't due to this counterexample!" work. Try that with the religious nutjobs.
        • by scheme (19778)

          Yes, but in said community counterarguments like "Here's the math and it works out, while your doesn't due to this counterexample!" work. Try that with the religious nutjobs.

          That doesn't happen as often as you'd think it does though. Depending on the field, a lot of the arguments revolve around details of the data analysis which can be somewhat subjective.

        • It's called philosophy. If the logic doesn't fit then your belief is in indefensible. The problem is most religious people have no foundation in philosophy beyond the philosohpy that's barely required to spread their religion.

          The real problem is religion is all known religions are rapidly falling out of sync with our understanding of the universe. Far Far quicker than we're learning new things. Where the religious authorities used to have centuries or millenia to compensate for new discoveries the mod

      • Scientists never [...] deride the work of their colleagues without merit.

        I thought science was exactly about deriding the work of your merit-less colleagues :)

    • Re:This is awesome (Score:5, Insightful)

      by Ohio Calvinist (895750) on Monday March 23, 2009 @06:27PM (#27304723)
      I think the statement needs a little intellectual honesty. I do agree that the scientific method when used properly is wonderful thing and this case is an example as such. However to limit "close mindedness" to "relgious" people sounds good on /. and gets you some cred with the groupthink crowd, but is pretty weak.

      It takes a high degree of personal humility to be open-minded. Particularly when you have a vested interest in a particular outcome, (beit relgious, scientific, political, etc...) many people to greater or lessor extents need to actively pursue impartiality. There are many spheres of life such as politics, sports, business, science, etc. where you find members of those communities not engaging in meaninful dialogue, because they have a vested interest in a particular ideology or theory or methodology.

      I have been in lectures where Ph.D.'s would not intellegently debate and discuss a particular set of data or therom contradictory of their own research/worldview. In some scientific fields there are positions you can take that will effectively kill your chances at a tenure-track faculty position; even if you are taken to those positions by the data against your will.

      On the other hand I've been in discussions of a religious or political nature where those in discussion where members were looking for insight from other members; including those who were diametrically opposed, because they recognized that they didn't have it all figured out and they'd either be convinced of an alternate or affirmed in their existing position. This isn't to say that religious, poltical, business communities are better or more open minded, or anything to that effect, just that your generalization simply isn't accurate.

      Science is great when it is really science. Science is truly lamentable when the theory trumps the data because the theorizer has far too much to lose if the theory is disproven or radically challenged; and broken theories are taught as immutable truth.
  • Cool. (Score:5, Funny)

    by Colourspace (563895) on Monday March 23, 2009 @05:57PM (#27304345)
    Just delays us nearer to 2012?
  • by gillbates (106458) on Monday March 23, 2009 @06:10PM (#27304509) Homepage Journal
    Research has led to the discovery of the heaviest element yet known to science. The new element, Governmentium (Gv), has one neutron, 25 assistant neutrons, 88 deputy neutrons, and 198 assistant deputy neutrons, giving it an atomic mass of 312. These 312 particles are held together by forces called morons, which are surrounded by vast quantities of lepton-like particles called peons. Since Governmentium has no electrons, it is inert; however, it can be detected, because it impedes every reaction with which it comes into contact. A tiny amount of Governmentium can cause a reaction normally taking less than a second, to take from four days to four years to complete. Governmentium has a normal half-life of 2-6 years. It does not decay, but undergoes a reorganization in which a portion of the assistant neutrons and deputy neutrons exchange places. In fact, Governmentium's mass will actually increase over time, since each reorganization will cause more morons to become neutrons, forming isodopes, not to mention multiple oxymorons. This characteristic of moron promotion leads some scientists to believe that Governmentium is formed whenever morons reach a critical concentration. That hypothetical quantity might normally be called 'critical mass' but, in this unique case it is known as 'critical mess'. When catalyzed with money, Governmentium becomes Administratium (Am), another just-discovered element that radiates just as much energy as Governmentium since it has half as many peons but twice as many morons.
  • young physicists (Score:4, Informative)

    by Goldsmith (561202) on Tuesday March 24, 2009 @08:45AM (#27310357)

    "If you haven't done anything in physics by the time you're 21, you never will."

    I've been told this quote comes from Heisenberg, and at the time I heard it, I thought it was a load of crap. However, the idea is correct. If you want to be a physicist, you have to be able and willing to jump into research right at the beginning (as an undergraduate), or you'll probably never do real research. Of course, most undergraduates don't end up finding bugs in code which has been checked by dozens of postdocs and grad students.

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