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CERN bids farewell to the LHC and enters Long Shutdown 3
https://www.nikhef.nl/en/news/final-run-for-the-current-lhc-accelerator-but-more-to-come/ https://www.nikhef.nl/en/news/final-run-for-the-current-lhc-...
- charmd 3mo agoI've read that CERN is storing more than 1 exabyte of collisions data these days (up from 600PB during the last long shutdown https://information-technology.web.cern.ch/sites/default/files/CERNDataCentre_KeyInformation_Nov2021V1.pdf https://information-technology.web.cern.ch/sites/default/fil...). Not too shaby...
- DiabloD3 3mo agoAll using ZFS, too
- dijit 3mo agouhoh, can only store 1000 of that dataset then. D:
- DiabloD3 3mo agoIn one pool, sure. You can have more than one pool.
- tempay 3mo agoNo they're not. At CERN physics data is on: * CTA for tape storage: https://cta.docs.cern.ch/v5/ https://cta.docs.cern.ch/v5/ * EOS for disk storage: https://eos-web.web.cern.ch/eos-web/ https://eos-web.web.cern.ch/eos-web/ There is a large CEPH cluster as well but that isn't really used for physics data.
- dcrazy 3mo agoMore specifically, from the EOS page: > Data is stored natively in XFS filesystems on hard disks or SSDs or on virtualised back-end storage (e.g. RADOS block devices) or distributed filesystems like Lustre or CephFS.
- DiabloD3 3mo agoInteresting, they used to be the largest ZFS user. Hard to Google for it without getting AI slop on it, but apparently they built their own stack in 2019. Not sure I like their solution, "Meta-data is persisted in RocksDB databases using a proprietary KV store called QuarkDB." Unless QuarkDB has magically removed RocksDB's amazing ability to corrupt and lose data frequently, this whole thing sounds like a bad idea. Also, their data is not stored on any one system (local XFS, Ceph, Lustre), a recipe for disaster.
- scheme271 3mo agoThere's at least 3 copies of all the data and possibly more spread around the world at different Tier1 and Tier2 centers. The T1 and T2 centers are very likely using different filesystems and everything is checksummed pretty much at every major step (data generation, before and after any network transfers, before analysis, etc).
- DiabloD3 3mo agoThe problem with RocksDB is Facebook uses it, and has a similar system that replicates data across the world... and still faces unrecoverable data loss because of RocksDB.
- pjmlp 3mo agoHaving done my little contribution to ATLAS TDAQ/HLT in the early 2000's, it is an interesting feeling to see the next steps taking shape.
- archimedes237 3mo agoHopefully no sophons appear.
- kridsdale1 3mo agoYou don’t want an ocular alarm clock?
- underlipton 3mo agoHyperstrategic origami.
- lyu07282 3mo ago[dead]
- nok22kon 3mo agobad timing with the price of RAM and NAND
- tempay 3mo agoMaybe not that bad, stopping the accelerator means the storage requirements drop now that data is no longer being taken. Storage is instead just used for simulation and reprocessing which is small in comparision. So long as the market recovers before HL-LHC starts and the data volume increases it'll be okay. If it doesn't...
- gojak 3mo agoThey will buy the hardware last, at the end of LHC to get the best hw possible. Helium is a bigger problem, since CERN is the biggest Helium cryo-installation in the world...
- kristopolous 3mo agoThe typo that sometimes got through in official literature still makes me giggle https://www.google.com/search?q=site%3Acern.ch+%22large+hardon+collider%22 https://www.google.com/search?q=site%3Acern.ch+%22large+hard...
- brokencode 3mo agoI feel like the title is a little overdramatic. They’re not saying goodbye to the LHC, they’re upgrading it to have 10x the power.
- cheschire 3mo agoby Tim the Particle Man Taylor
- sigmoid10 3mo agoProbably because the upgrades to the collider are so significant that it will be called the HL-LHC afterwards.
- jdironman 3mo agoHella Large - Large Hadron Collider?
- onion2k 3mo agoHo-Ly - LHC maybe.
- moi2388 3mo agoHigh luminosity large hadron collider
- someonebaggy 3mo agoI think it stands for Huge Large Large Huge Colossal, in reference to its size.
- cern 3mo agoThey missed an opportunity to add 'Colossal' to the beginning, so the acronym would be supersymmetric -- the CHL-LHC
- p1mrx 3mo agoThey're collecting 10X more data, at roughly the same energy per collision.
- ursuscamp 3mo agoToo late, damage is already done. We have been on the wrong timeline for years at this point.
- drybjed 3mo agoEl Psy Kongroo.
- agar 3mo agoI wonder whether the cancellation of the superconducting supercollider was a net positive or negative for science. If it continued to completion, it would have had almost 3x the beam energy of even the upgraded LHC in 2030 (20TeV vs. 7TeV). But the questions are fundamentally political, not scientific: Would SSC operations and funding have continued through the US economic challenges of 2001, 2008, and 2020? I could see a timeline in which the SSC got built and discovered the Higgs boson before LHC came online, causing the LHC to be canceled, delayed, and/or starved of funding -- only for the SSC to be shuttered during the "great recession" of 2008 or during any other US Gov't belt tightening exercise. Today we would have neither the SSC nor the LHC. Or, perhaps SSC would have accelerated other discoveries by 10 to 15 years (SSC go-live was to be in the late-1990's versus LHC's Higgs discovery in 2012).
- pfdietz 3mo agoPerhaps SSC's cancellation avoided a nightmare scenario where all that energy beyond what was needed to find the Higgs was wasted. And perhaps Science as a whole benefited from diversion of resources away from fundamental particle physics.
- agar 3mo agoPerhaps. I do remember the discussion about whether the SSC consumed so much basic research funding that other areas would have their funding significantly constrained. Basic research has such a long time horizon it's interesting to think of the fundamental grants that might have been affected. Quantum computing? CRISPR? mRNA?
- adgjlsfhk1 3mo agoFrom what I've heard, the SSC would have had higher power, but much worse luminosity (i.e. much more noise) than the LHC.
- usernamed7 3mo agoI was surprised to see .cern as a TLD - i would not expect it to need a family of websites in the way .gov or .mil do.
- andrewf 3mo agoIt's a brand gTLD, like .microsoft and .google. https://en.wikipedia.org/wiki/Generic_top-level_domain#Brand_gTLD https://en.wikipedia.org/wiki/Generic_top-level_domain#Brand...
- oliyoung 3mo agoTo be fair, if any org deserves a vanity TLD it's CERN
- saghm 3mo agoYeah, given that the web was basically invented there, it seems pretty reasonable
- pezezin 3mo agoCERN is so big that they have their own IXP: https://cixp.net/ https://cixp.net/ Also, the web was invented at CERN, so like the other comment said, if someone deserves at gTLD is them.
- gojak 3mo agoActually, in the 2000's CERN was the biggest internet exchange point in Switzerland, while the physical datacenter was not in Switzerland but in France xD
- Cockbrand 3mo agoI was too, and I was going to ask whether this is a good use of taxpayer money, as the ICANN fee for registering a TLD is $227,000. But given the fact that the Web was invented at CERN, I could imagine that they got a special deal. Happy to learn about details if someone knows more!
- sigmar 3mo agoI visited CERN last July. Was lucky enough to get into a group tour. The tour guide was a postdoc researcher who said the only times that public tours are allowed to take an elevator down is during long shutdowns. So while they do this work on LHC might be the best time to swing by for a tour (I might even try to return). Even without the descent, my tour was great with showing the 70 year timeline, historical early particle accelerator equipment, and a cool view of the ATLAS control room. The facility is awe inspiring and a testament to Europe's willingness to make long-term commitments to furthering science research for the public good.
- buildbot 3mo agoI worked on a tiny, tiny part of the research for the insertable B layer in ATLAS during long shutdown one as an undergraduate - the 3 year period allowed all the detectors to be upgraded significantly! It will be interesting to see how the current systems are upgraded during this shutdown. Sounds like the ITK for ATLAS is absolutely _insane_ compared to the insertable B layer - 5 billion channels, up from 8 million. I wonder if ITKpix is at all similar to the T3MAPs cmos or FEI4 sensors we worked with… Edit Looks like it’s very different; and really cool: https://cds.cern.ch/record/2928802/files/ATL-ITK-PROC-2025-011.pdf https://cds.cern.ch/record/2928802/files/ATL-ITK-PROC-2025-0...
- ComputerGuru 3mo agoAm I the only one that feels three/four years is a mighty ambitious timeline for the upgrade? It seems to be a very significant undertaking…
- scheme271 3mo agoIt's been in the planning stages for at least 5-8 years at this point. The instruments and upgrades have been tested and validated so it's just putting stuff together and then validating/calibrating. Stuff can still happen like the splice issue and repairs.
- xAlecto 3mo agoKeep in mind this is for the hardware work. We have been working on the HL-LHC from the physics / beam dynamics / everything else side for close to a decade now. The other machines in the complex, which we call "injectors" from our mighty tower, have already undergone their own upgrade to be ready for HL-LHC, the LIU (https://home.cern/accelerator-chain-prepares-high-luminosity/ https://home.cern/accelerator-chain-prepares-high-luminosity...). Nonetheless there are plenty of things to be done and a lot of technologically engaging challenges ahead so this 3-4 years is still ambitious ;)
- servo_sausage 3mo agoThe LHC is such a crazy thing; kilometres of strange infrastructure, thousands of people, all for what seems like pure scientific curiosity. I think only surpassed by the SETI program in terms of doing it because many nerds think it's really cool.
- otabdeveloper4 3mo agoPoliticians think it's a moonshot project at finding another nuclear bomb type of thing. (None of this would ever be funded without the tenuous nuclear weapons connection.)
- KeplerBoy 3mo agoThat doesn't sound like something one would want to do in cooperation with the entire rest of the world.
- otabdeveloper4 3mo ago> with the entire rest of the world Uh, did you really mean that? The "entire" rest of the world? Even Iran and North Korea? Well, it seems the "entire rest of the world" is only the so-called "good guys", according to the current political regime funding it.
- SiempreViernes 3mo agoPlease just stop typing this sort of nonsense.
- otabdeveloper4 3mo ago> nonsense I'm intimately familiar with how high-energy physicists get hired and funded. The funding comes from the political and budget bucket labeled "nuke stuff". E.g., Fermilab is under the U.S. Department of Energy. CERN is funded by the European Organization for Nuclear Research. Etc., etc. Politicians fund this stuff only because it triggers their wunderwaffen FOMO.
- max-ch 3mo agoI was visiting CERN on one of their Open Days during the previous shutdown. This is one of the rare occasion where visitors can enter the LHC. I walked for about 500m along the beam which is remarkably small despite all its protection. Standing inside LHCb (one of the experiments where they track collisions) was one of my most awe-inspiring moments about science and technology. Photos don’t do it justice. It’s a multi-story building underground, but every inch is covered with cables, sensors etc. Seeing it on photos is one thing, standing inside the biggest machine built by humankind is a completely different experience and hard to put into words. The amount of thinking and planning that went into it is insane. CERN staff is super-friendly and open to talk and explain. If you have the possibility to visit, do it - especially with guided tours and on their annual Open Days.
- dylan604 3mo agoAs a high school kid taking physics, we got to tour the Superconducting Super Collider campus. Obviously, this was nothing compared to being next to something that was actually built and did science, but they had a the various instruments and segments the beam tube with the magnets on display. Some students would intern there during the summer. The plug was pulled by Congress before I could apply. That was my introduction to politics in science where the kid like notions of how things worked were shattered.
- adastra22 3mo agoYou can still tour the SSC. Just requires wire cutters and a bit more spelunking.
- amarant 3mo agoDamn that sounds fun! How big a risk of being shot would I be running if I tried this?
- adastra22 3mo agoA non-negligible risk. More likely to get lost and drown. I wouldn't do it. But you can read about it: https://medium.com/@liboski/the-superconducting-super-collider-b96eb9abf794 https://medium.com/@liboski/the-superconducting-super-collid... https://weburbanist.com/2014/09/11/the-desertron-worlds-largest-super-collider-lies-abandoned/ https://weburbanist.com/2014/09/11/the-desertron-worlds-larg...
- s5300 3mo ago[dead]
- zombot 3mo agoThe LHC is dead, long live the HiLumi LHC!
- xAlecto 3mo agoFor anyone interested in doing some very special visits this will be a good timing. Long Shutdowns are the only moments where a lot of usually inaccessible places can be visited. There should be (not yet officially confirmed) an open days after summer next year, just like there was in 2019. Short time frame but for a few days everything(-ish) is accessible, including going down in the LHC tunnel, but many more crazy places. In the meantime there are still permanent exhibitions and guided tours for those interested. Come have a look at the cool science (made with your taxes)!
- andai 3mo agoWow, end of an era. Does this mean the timeline finally goes back to normal? ;)
- nasso_dev 3mo agouh oh... does anybody here have a divergence meter?