The Full Moon has a measurable effect on particles in LHC
DrCaleb @ Thu Jun 07, 2012 1:49 pm
$1:
The shift crew (about ten people plus dozens of experts on call) must keep the detector running smoothly, tackling every problem, big or small, as fast as possible.
Data was coming in at a high rate and all sub-detectors were humming nicely. Not a glitch in hours so we were getting slightly sleepy nearing the end of the shift around 22:00. So when a colleague from the trigger system (the system that decides which events are worth keeping) called to inquire about recurrent splashes of data, I was rather puzzled.
I quickly went around, asking a few shifters to check their system. Nobody had a clue. Then I took a closer look at this plot that I had not scrutinized before since everything was so seamless.
The two lower curves in beige and green show the instantaneous luminosity measured by the two largest detectors operating on the Large Hadron Collider (LHC), CMS and ATLAS. This is a measure of how many collisions are happening per second in each experiment from the two beams of protons circulating in opposite direction in the LHC tunnel. If you look closely at these curves, they both have small dips at regular intervals. Since both ATLAS and CMS were registering these dips, it had to be coming from a common source, the LHC.
So I called the LHC control room to find out what was happening. “Oh, those dips?”, casually answered the operator on shift. “That’s because the moon is nearly full and I periodically have to adjust the proton beam orbits.”
Data was coming in at a high rate and all sub-detectors were humming nicely. Not a glitch in hours so we were getting slightly sleepy nearing the end of the shift around 22:00. So when a colleague from the trigger system (the system that decides which events are worth keeping) called to inquire about recurrent splashes of data, I was rather puzzled.
I quickly went around, asking a few shifters to check their system. Nobody had a clue. Then I took a closer look at this plot that I had not scrutinized before since everything was so seamless.
The two lower curves in beige and green show the instantaneous luminosity measured by the two largest detectors operating on the Large Hadron Collider (LHC), CMS and ATLAS. This is a measure of how many collisions are happening per second in each experiment from the two beams of protons circulating in opposite direction in the LHC tunnel. If you look closely at these curves, they both have small dips at regular intervals. Since both ATLAS and CMS were registering these dips, it had to be coming from a common source, the LHC.
So I called the LHC control room to find out what was happening. “Oh, those dips?”, casually answered the operator on shift. “That’s because the moon is nearly full and I periodically have to adjust the proton beam orbits.”
http://www.quantumdiaries.org/2012/06/0 ... operators/
BartSimpson @ Thu Jun 07, 2012 1:56 pm
I love the reaction of the tech - just noting how he handles something that, in and of itself, is a remarkable finding. 
DrCaleb @ Thu Jun 07, 2012 2:56 pm
BartSimpson BartSimpson:
I love the reaction of the tech - just noting how he handles something that, in and of itself, is a remarkable finding.
I laughed at that too.
If you took a grapefruit, and a grape and put them 6' apart, that would be a rough analogy of the Earth and Moon. I'm amazed that the weakest force, gravity, is capable of exerting any deflection at all on the LHC from that far away.
BartSimpson @ Thu Jun 07, 2012 3:10 pm
I suspect it may not be gravity causing the change. It *looks* like gravity but where it's not exactly acting the way it should I'd estimate it is something different and currently unknown.
Sort of like how aluminum and iron have similar properties yet one is different from the other.