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Princeton Student Finds Bug In LHC Experiment

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.'"

15 of 243 comments (clear)

  1. If it smells, it's chemistry, by MadMidnightBomber · · Score: 5, Funny

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

    --
    "It doesn't cost enough, and it makes too much sense."
  2. Re:wha? by Anonymous Coward · · Score: 5, Funny

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

  3. Re:wha? by Quothz · · Score: 5, Informative

    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.

  4. Not a hardware bug by rminsk · · Score: 5, Informative

    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.

    1. Re:Not a hardware bug by Anonymous Coward · · Score: 5, Informative

      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.

  5. Re:wha? by Anonymous Coward · · Score: 5, Funny

    Off topic: Miss Quan is cute.

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

  6. A concentrator! by hellfire · · Score: 5, Funny

    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.

    --

    "All great wisdom is contained in .signature files"

    1. Re:A concentrator! by Walkingshark · · Score: 5, Funny

      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...

      --
      The world you experience is only a close approximation of reality.
  7. Re:wha? by Red+Flayer · · Score: 5, Funny

    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.

    --
    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
  8. This is awesome by adpe · · Score: 5, Insightful

    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!

  9. Re:Great story. by Gromius · · Score: 5, Informative

    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.

  10. Re:God made women to debug by hobbit · · Score: 5, Funny

    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.

    --
    "Wise men talk because they have something to say; fools, because they have to say something" - Plato
  11. Re:She is hot!! by Hork_Monkey · · Score: 5, Funny

    She'd also find all those bugs crawling around.

  12. Implications for discovery of new particle. by gillbates · · Score: 5, Funny

    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.

    --
    The society for a thought-free internet welcomes you.
  13. Bush also found an error in Fermilab calculations by noidentity · · Score: 5, Funny