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How the Moon Affects LHC Operations

Posted by Soulskill on from the werewolves-loose-at-cern dept.

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.'"

41 of 64 comments (clear)

  1. Simple solution by Anonymous Coward · · Score: 3, Funny

    BLOW UP THE MOON!

    1. Re:Simple solution by jd · · Score: 1

      Didn't Gerry and Sylvia Anderson do this in 1999?

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    2. Re:Simple solution by arun84h · · Score: 3, Funny

      http://www.youtube.com/watch?v=Csj7vMKy4EI

    3. Re:Simple solution by BenSchuarmer · · Score: 1

      So Abian was right all along?

    4. Re:Simple solution by geogob · · Score: 2

      I thought it was what they were trying to do with their blackhole factory...

    5. Re:Simple solution by Iskender · · Score: 1

      So Abian was right all along?

      Plus points for old school. I only just managed to read this on my WebTV.

    6. Re:Simple solution by aynoknman · · Score: 1

      If you think the moon is bad, see how a nearby black hole affects the LHC. If you think a nearby black hole is bad, see how a black hole caused by the LHC affects the LHC

      --
      We need a "+1 -- nice sig" moderation.
  2. Interesting by History's+Coming+To · · Score: 3, Interesting

    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?

    --
    Please consider this account deleted, I just can't be bothered with the spam anymore.
    1. Re:Interesting by Anonymous Coward · · Score: 3, Informative

      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.

    2. Re:Interesting by phrostie · · Score: 1

      or possibly passing asteroids.

    3. Re:Interesting by Anonymous Coward · · Score: 2, Informative

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

    4. Re:Interesting by Anonymous Coward · · Score: 1

      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 physicists working in the LIGO-VIRGO Collaboration are dedicated to the problem of suppressing environmental and systematic noise sources, and some very sophisticated technologies have been developed to that end. And we still haven't detected any gravitational waves yet!

    5. Re:Interesting by Anonymous Coward · · Score: 1

      Surprised nobody has pointed this out
      Eurofighter Typhoon and the Moon

    6. Re:Interesting by Jeff+DeMaagd · · Score: 1

      You're talking about very different devices though. LIGO is a considerably more specialized device than LHC, it's designed to do only one kind of experiment. Particle accelerators are more versatile.

      That said, I'm not sure if LHC has actually discovered anything. They've taken data, and found interesting data but I don't think anyone's done complete analyses on that data to show an actual discovery.

    7. Re:Interesting by EdIII · · Score: 1

      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 parsec of a star system and you see you vacation requests and sick days just skyrocket.

  3. Well by wideBlueSkies · · Score: 1

    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.

    --
    Huh?
    1. Re:Well by jd · · Score: 1

      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.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    2. Re:Well by Zocalo · · Score: 3, Informative

      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.

      --
      UNIX? They're not even circumcised! Savages!
    3. Re:Well by RightwingNutjob · · Score: 1

      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.

    4. Re:Well by jd · · Score: 1

      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 point is that you can ALWAYS take measurements to fix errors, and that fixes beforehand will ALWAYS produce cleaner, more repeatable results than adding in fixes after the fact, especially when you can't be sure of all the facts beforehand.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    5. Re:Well by kermidge · · Score: 1

      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 building it? Where were your comments and your wonderful insight before this 'news' was published?

      Sorry, jd, that was in response to another post, but I'm lazy, half-drunk, and tired, so it's a lump.

      I think your timing idea is interesting, wonder if it's been thought of and done - I don't follow CERN closely.

      Running a calibration beam? Intriguing; yet how would one handle magnetic migration or collision, in other words, how to keep two beams separate within the same magnetic envelope? This issue, related ones, and more, seem to crop up repeatedly in various areas of fusion research and engineering from what I've read. There they're dealing with just one equivalent of beam or bottle. Um, bad memory, but wasn't this tried at Batavia? Or even back at LINEAC?

      Your last part viz. "you can ALWAYS...", I ain't so sure of that. All I know is from wood: measure twice, cut once. I've no idea if'n it translates, or just how, to LHC.

      Your sig reference is unknown to me; I'm still on walrus and carpenter. N'er mind, found it, thanks: lyrics alone worth the search.

    6. Re:Well by Isaac-1 · · Score: 1

      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?

    7. Re:Well by toruonu · · Score: 2

      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 was calmly saying he has to adjust for moon's tide as it's part of their operating procedure. Same goes to monitoring the rain quantity and snow melting to knowing what the water level is in lake Geneva so that they can compensate for that too.

    8. Re:Well by jd · · Score: 1

      It's unlikely but nonetheless possible that the LHC is running software I wrote when working for CERN. If so, they are suffering enough.

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    9. Re:Well by kermidge · · Score: 1

      Why you're replying to me I've no idea, 'cuz I figured nothing out. Perhaps a mis-placed "reply" choice. I found it fascinating that with all the gee-whiz boffinry going on the past twenty years that led to building and running the LHC that this bit viz. tides and lake levels and such didn't happen to occur to anyone. Seems to me it's one of those things that seem so damn obvious after the fact, but in real life happens when people do complex new stuff.

    10. Re:Well by jd · · Score: 1

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

      --
      It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
  4. Need to keep Peter away.. by Brad1138 · · Score: 1

    Peter Griffin

    --
    If you could reason with religious people, there would be no religious people
  5. A different headline would be better... by tlambert · · Score: 5, Insightful

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

    -- Terry

  6. Re:Yes... Well... ummm by bughunter · · Score: 1

    Yes, but our instruments are not yet sensitive enough to detect the effects.

    --
    I can see the fnords!
  7. Full Moon by Anonymous Coward · · Score: 5, Funny

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

    1. Re:Full Moon by Anonymous Coward · · Score: 1

      Actually, not only is this true, TFA says this is the case. The moon doesn't change mass, but a full moon implies the moon and sun are aligned, and therefore the tidal force is greater. This is the same effect that causes spring tides.

  8. Re:how strange... by Hatta · · Score: 3, Insightful

    The crazy thing is that most of those incredibly smart people doing those amazing things are just as stupid as the rest of us in other ways.

    --
    Give me Classic Slashdot or give me death!
  9. The Quantum Diaries by Spinalcold · · Score: 3, Informative

    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

  10. Re:Your mom by drinkypoo · · Score: 1

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

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  11. Protip to submitter... by bogie · · Score: 1, Insightful

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

    --
    If you wanna get rich, you know that payback is a bitch
    1. Re:Protip to submitter... by Anonymous Coward · · Score: 1

      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.

    2. Re:Protip to submitter... by TeknoHog · · Score: 1

      It stands (pun intended) for Large Hardon Collider. It is the Real Men's (aka physicists') version of a cockfight.

      --
      Escher was the first MC and Giger invented the HR department.
  12. Re:Your mom by kyrsjo · · Score: 1

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

  13. Re:gravety wave detector by Barryke · · Score: 1

    Doc this is 2012. You wasted another otherwise perfect timeline!
    You where not supposed to disclose that until EUTC 21120103T23:04:31:0#.

    --
    Hivemind harvest in progress..
  14. Re:Your mom by drinkypoo · · Score: 1

    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?

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  15. Disappointed... by Eaglehawk · · Score: 1

    After reading the headline, I was looking forward to reading an article about LHC scientists have been transformed into werewolves...