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How the Moon Affects LHC Operations 64

New submitter NervousWreck writes "Physicists report that tidal conditions are affecting the hardware at the LHC. 'This effect has been known since the LEP days, the Large Electron Positron collider, the LHC predecessor. The LHC reuses the same circular tunnel as LEP. Twenty some years ago, it then came as a surprise that, given the 27 km circumference of the accelerator, the gravitational force exerted by the moon on one side is not the same as the one felt at the opposite side, creating a small distortion of the tunnel. Since the moon’s effect is very small, only large bodies like oceans feel its effect in the form of tides. But the LHC is such a sensitive apparatus, it can detect the minute deformations created by the small differences in the gravitational force across its diameter.'"
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How the Moon Affects LHC Operations

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  • by Anonymous Coward on Friday June 08, 2012 @06:15PM (#40263327)


  • How strange that so many humans can be so smart and do so many amazing things and yet so many others are so stupid in so many other ways.

  • Interesting (Score:4, Interesting)

    by History's Coming To ( 1059484 ) on Friday June 08, 2012 @06:18PM (#40263367) Journal
    They also had problems with an intermittent "rogue signals" which later turned out to match the timetable of a nearby railway. I wonder whether it could, in theory at least, detect gravity waves?
    • Re: (Score:3, Informative)

      by Anonymous Coward

      They also had problems with an intermittent "rogue signals" which later turned out to match the timetable of a nearby railway. I wonder whether it could, in theory at least, detect gravity waves?

      Not without much more sensitive equipment. Projects like LIGO that look for gravity waves have 4km long tunnels that they use for laser interferometry. That gives them much more sensitivity than the LHC can dream of having with it's setup and electronics.

      • Re: (Score:2, Informative)

        by Anonymous Coward

        The LHC is 27KM times the number of times an beam has to be accelerated.

    • or possibly passing asteroids.

    • by Anonymous Coward

      That's what LIGO [] and VIRGO [] are trying to do. It turns out that it's actually extremely difficult to detect gravitational waves (the most promising sources being collisions between compact objects []), and the sensitivities required are far, far beyond what the LHC could achieve. It essentially amounts to detecting a change in length of the detector arms of around 1 part in 10^21. That's like a 0.001mm change in the distance from Earth to the nearest star.

      More or less the entire contingent of experimental physi

    • by Anonymous Coward

      Surprised nobody has pointed this out
      Eurofighter Typhoon and the Moon []

    • by EdIII ( 1114411 )

      That's a lot smarter than my first thought which was that it could be used as an early warning system for a Death Star coming into orbit and getting ready to fire.

      Alderaan could have really used one of those. Although they were the first so it would be kinda hard to put the danger into the proper context.

      After the first use, I would imagine the rest of the galaxy kept close tabs on where that fucker was. Probably messed with local economies the same way cops do on the roads. Death Star gets within a pars

  • Kind of a cool problem. I suppose that short of altering the moon's orbit, someone is going to have to build adjustments into the software... Would that even be possible? Such adjustments or approximations might invalidate results.

    Oh the hell with it.... I'm tired of thinking logically today. I need a beer.

    • by jd ( 1658 )

      It might be better to run beams of known parameters and adjust the controlling magnets accordingly so that the beam is perfectly circular. The moon won't move enough between a calibration run and an actual run for the results to be invalid, and calibrating the magnets will be easier than calibrating the software.

      • The moon won't move, but the earth will spin merrily along at 15 arcsec/sec and change the orientation of the ring relative to the moon.
        • by jd ( 1658 )

          If they can handle an uncalibrated ring and just wait for the moon to be in roughly the right place, then calibrating all the magnets before each run and enduring a change in tidal forces due to motion of 54,000 arcsecs (15 arcsecs/sec over the course of one hour) for any given one hour experiment will logically produce superior results to guesstimating.

          Adding in a non-colliding ring whose sole purpose it is to provide continuous feedback for calibration purposes would logically improve results further.

          My p

          • I suggest that the issue, and the news of it, is not discovering gravity but rather the finding, delineating, understanding, and compensating for the effects of various celestial bodies and transient local phenomena - some of which might not have been totally obvious beforehand. This is new stuff, people, it's never been done before on anything like this scale, d'you think even your brighter fellow humans might not have considered _everything_ imaginable beforehand? Did you, all the years they were build

            • by jd ( 1658 )

              If you haven't seen their music-hall production of the album, it is PRECISELY what you'd expect from that lot.

    • Re:Well (Score:4, Informative)

      by Zocalo ( 252965 ) on Friday June 08, 2012 @07:15PM (#40263977) Homepage
      With hindsight, this probably shouldn't be a big surprise. There were some reports [] earlier this year about Loch Ness having a small but measurable tidal activity; something like 1.5mm across its 35km length. Given that the instruments at the LHC are apparently so finely tuned that they can track continental drift[1], it shouldn't really come as a major revelation that they can detect lunar tidal activity across the diameter of the LHC.

      [1] Coincidentally, I found out about this as part of the whole issue over neutrinos supposedly travelling faster than light, which was finally given the official "no they don't" [] by CERN today.
      • by Isaac-1 ( 233099 )

        Am I the only one that is concerned that this came as a surprise? These people are supposed to have PhD's in Physics, and they don't think the big rock in the sky might have an effect on their toy?

        • I think the "surprise" part was only to the ATLAS controller. The fact that tidal forces affect the beam has been known since LEP times as is the water level in lake Geneva and also the TGV schedule that used to have huge electricity spikes as they "grounded" their lines and said grounding happened to reach LHC 100m below causing the orbit of the beam to jump. Hell, I've been working in the CMS experiment since 2004 and I knew about the tidal force compensation need and that's why the LHC control room guy w

  • by tlambert ( 566799 ) on Friday June 08, 2012 @06:21PM (#40263401)

    "LHC Experiment discovers gravity; Higgs Boson still missing, presumed dead."

    -- Terry

  • Does the gravity field of your mom also affect this sensitive apparatus?

    • Your mom is so fat she has smaller fat women orbiting her.

      • by kyrsjo ( 2420192 )

        You know the mass of the orbiting bodys doesn't really matter, unless they are comparable in size?

        • You know the mass of the orbiting bodys doesn't really matter, unless they are comparable in size?

          You know the plural of body is spelled with an I E S? Oh, I guess you don't.

          You know that when you overanalyze a joke, you're putting the anal in asshole?

  • Full Moon (Score:5, Funny)

    by Anonymous Coward on Friday June 08, 2012 @07:48PM (#40264317)

    I would guess that this is more of a problem when there's a full moon since the mass must be greater then.

  • The Quantum Diaries (Score:3, Informative)

    by Spinalcold ( 955025 ) on Friday June 08, 2012 @08:39PM (#40264645)
    The Quantum Diaries is one of my favorite blogs, it's updated by particle, nuclear and plasma scientists all over the world. They have a great range of topics too, not just about the data coming out of the LHC and the range of theories, but also the life of a scientists, how papers are published, covering conferences, heck even on the day in the life of cleaning a detector. It's a field I'm working to get into, so it's especially of interest to me but I recommend it to anyone interested in the world of high energy physics.

    On a side note, there's a write up of what was talked about the the Neutrino Conference that happened last week. Even aside from faster than light travel, they are finding some very [] weird [] things []
  • by bogie ( 31020 )

    Don't assume everyone knows what "LHC" stands for.

    • by Anonymous Coward

      If you don't know the name and acronym of the greatest experiment of mankind to date, maybe you don't really belong on a site for nerds. Just saying.

    • It stands (pun intended) for Large Hardon Collider. It is the Real Men's (aka physicists') version of a cockfight.
  • After reading the headline, I was looking forward to reading an article about LHC scientists have been transformed into werewolves...

Karl's version of Parkinson's Law: Work expands to exceed the time alloted it.