CERN’s Ambitious Plan to Build the Largest Particle Smasher Ever

dragulagu said:
Just read the article as well, love this stuff. It's amazing how hey use the specific density (and assuming specific composition) properties of these crystals for this purpose.
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Most memorable thing I was told by a high astrophysicists, "dude, you know you can still do pretty cool experiments in your basement that isn't irrelevant." (highly paraphrased, but never know, that goatface could be reading this).

Scintillating materials and photo multipliers are pretty neat, and in most cases its about applying voltage to make it unstable so two electrons are knocked around by one photon, and then those known another 4, then 8 all the way until a measurable current. That's basically how it detectors work unless they are pixel detectors which is a bit more boring as the "shape" of this cascade can say something about spin (charge?) and other properties of whatever caused it.

Then try a nobel gas that gets applied 200k volts to it with detectors plates that register clusters of electrons that can knocked loose and slams into the end places. This allows you to reconstruct a path it took, while it's called "time projection chamber" -- yeah whatever -- you detect a projection given a little bit of time as this slams into the detector plates.

So the cables for one of these things delivering 200k volts were properly secured, like wtf, secuing a couple of tons of copper cables? Turned out that the "weight" of the electrons in the cables caused quite a bit of movement as the LHC magnets switched direction in front and behind of the "bunches".

Yeah, the experiments are cool! :) These clowns talking about strings and higgs fields aren't.
 
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Can't help myself as statistics, philosophy of science and scientific methods were discussed here.
Found a good analogy for how to explain the thing about statistics in science.

Let's theorize and hypothesise about how lethal it is to headbutt axes and shoot yourself in the head.
We theorize they are both pretty lethal and the gun is likely more lethal than axes, and that in the latter case depending where the sharp end is may be less and that a gun is 100% lethal.

So we put the insanity to the test and discover to amazement that the gun isn't always lethal, so what gives?

Turn out the experiment isn't perfect and that there are indeed errors in bullets.

This may or may not have been a humane experiment, and depending on the statistical requirement none or quite a few may still be alive within the statistical fluke between working guns and failing bullets.

Now this is worth thinking about, as I had a *nudge nudge*, "know how many higgs events where they detected and accounted for all the energy in collision at 5 sigma announcement?", "About 5 between both CMS and ATLAS". And if I remember correctly, a few years with 40 million collisions per second, that's pretty noisy where some particles have pretty abysmal acceptance rates for detection.

Now the statistics and maths is fine, but certain errors rates are quite large and ball park. Like 5% systematic and 20% theoretical for some things.

https://en.wikipedia.org/wiki/Look-elsewhere_effect
https://xkcd.com/882/

Now where did we leave that Tram schedule and other friends that should have been calibrated or compensated for. Yeah it's fine, there is a particle, and i don't have a problem with the higgs field/effect, just don't buy the whole package.
 
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Ifur said:
Scintillating materials and photo multipliers are pretty neat, and in most cases its about applying voltage to make it unstable so two electrons are knocked around by one photon, and then those known another 4, then 8 all the way until a measurable current. That's basically how it detectors work unless they are pixel detectors which is a bit more boring as the "shape" of this cascade can say something about spin (charge?) and other properties of whatever caused it.
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Yeah I do recall this explanation during my visit at the CMS, the cascading / amplification of the particles against different layers in the detectors and a server farm to post-process all the data. The radiation shield is also massive.

Ifur said:
Turned out that the "weight" of the electrons in the cables caused quite a bit of movement as the LHC magnets switched direction in front and behind of the "bunches".
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O_o That's....impressively scary. I do recall the LHC having some problems as well with cryogenic temperature stability previous year (or in 2016/2017?), I saw a lot of shutdowns during the operation on the vistars.

Ifur said:
Now this is worth thinking about, as I had a *nudge nudge*, "know how many higgs events where they detected and accounted for all the energy in collision at 5 sigma announcement?", "About 5 between both CMS and ATLAS". And if I remember correctly, a few years with 40 million collisions per second, that's pretty noisy where some particles have pretty abysmal acceptance rates for detection.

Now the statistics and maths is fine, but certain errors rates are quite large and ball park. Like 5% systematic and 20% theoretical for some things.
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If I do recall correctly they would only publish a discovery when indeed at least 2 research sites on CERN discover the same event with strong certainty through their infrastructures? I'm a bit astonished that it's only 5 sigma 5 detections in total between both that made the discovery, that's a poor amount. So I get your point in this.
I assume that's also why they are specifically doing these upgrades now? To make the verification of the Higgs particle a certainty (or lose face and probably the whole funding to the project).
 
dragulagu said:
If I do recall correctly they would only publish a discovery when indeed at least 2 research sites on CERN discover the same event with strong certainty through their infrastructures? I'm a bit astonished that it's only 5 sigma 5 detections in total between both that made the discovery, that's a poor amount. So I get your point in this.
I assume that's also why they are specifically doing these upgrades now? To make the verification of the Higgs particle a certainty (or lose face and probably the whole funding to the project).
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You may be thinking of a quick Nobel? Five sigma is good enough for a collaboration to claim discovery without losing any face.
 
dragulagu said:
o_O That's....impressively scary. I do recall the LHC having some problems as well with cryogenic temperature stability previous year (or in 2016/2017?), I saw a lot of shutdowns during the operation on the vistars.
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Yes, apply massive magnetic fields to large copper cables carrying a crap load of voltage in a tonnage of cables, and the whole mess becomes like a rabbit humping the structural integrity of the detector.
 
dragulagu said:
Ehm correct, I seem to have misunderstood what essentially a 5 sigma discovery is.
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And I forgot to comment on the CMS visit, so never seen it! Never seen LHCb either, but did have an actual dosimeter and courses that allowed med down there. Never bothered a hazmat course with gas masks and the works to be allowed close to the actual LHC however. And at some point in the early days, during shut down when guests are allowed down there, anyone a member of an experiment had virtually free access to roam around!

Tho, been told that CMS is amazing to look at when the doors/detector are actually open during a shutdown long enough for it (take days to open some doors). And if the magnets are turned on -- CMS having the strongest one -- to be allowed to balance a wrench horizontally on your finger.

On the other hand, heave heard things like, "were minding my own business measuring the magnetic field during construction, and some idiot tried to kill me with a screw driver he forgot to remove from hit shirt pocket, barely missed my head". But you get asked and told about metal and fillings in your teeth and what eddy currents are and how that works under a 4 tesla magnetic field that CMS has for example.
 
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Ifur said:
Tho, been told that CMS is amazing to look at when the doors/detector are actually open during a shutdown long enough for it (take days to open some doors). And if the magnets are turned on -- CMS having the strongest one -- to be allowed to balance a wrench horizontally on your finger.
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It's amazing to look at, it is a huge machine. Takes a while to go down there as well. We were there during a maintenance time, so it didn't take too long to get down to it.
Here's the photo album from it, feel free to look around in it: https://photos.app.goo.gl/oGH2WaBhmZDESZZH6 , there's also a shot in there of the shielding and a cross-section of one of the detectors.
 
I remember the first time I came across an article when they were planning on building the Large Hadron Collider, when the image was just a huge red circle on a map that cut across the two countries. There I was, while my friends were discussing the latest sneakers, I was considering just how huge the LHC was going to be and what was going to happen when they smashed the atoms, something humans had never done before...I have been fascinated since. The news that an even larger collider will be built is just amazing, the current one is 27km long and the new one will be 100km! I dont pretend to understand everything I read regarding the experiments and results but damn, if i dont enjoy being in that space with all those geniuses, little old me just trying to get a nugget of that knowledge ill probably never share with anyone I come across.....except in this forum!!!
 
Sometimes Yeah said:
I hope they don't create a strangelet particle. The mini black hole concern was bs, but these types of particles catalyze the conversion of ordinary matte into their odd spin states.
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I remember reading a paper that eased those black hole fears, I know most of it was above my IQ but I did know that what I read made sense and I stopped worrying about them creating holes in time in Switzerland.
 
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