I 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 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.
As 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.
I 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).
Perhaps 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.
Perhaps. 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?
That's the wiki article for the new one. Says "Increasing LHC luminosity involves reduction of the beam size at the collision point, and either the reduction of bunch length and spacing, or significant increase in bunch length and population."
The linked article says the new one will have "between 140 and 200 proton–proton collisions in every bunch crossing, compared to around 60 during the last LHC run." So the "10x luminosity" seems to be composed of ~3x more protons at a time along with presumably a ~3x tighter focused beam.
I had to chuckle a week or so ago when I was bumbling across the internet and landed on an article that had a link to a nutjob page where the title was something like: "CERN found something so disturbing they had to shut down immediately".
The nutjob article (yes, I did read it, LOL) suggested that they had found some universal truth maybe about God or aliens or something, and it scared them so much they just noped out of the science business to prepare themselves for the inevitable revealing of the "truth".
It is truly no wonder that so much of society is so fundamentally fucking stupid when their trusted information sources are so full of obviously false bullshit.
I can't wait until the LHC is back online zipping tiny things around the ring again in a cosmic demolition derby to find the smallest specs of our reality and give them all whimsical names.
I 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…
I 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.
> 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.
Interesting, 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.
Politicians 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.)
Maybe 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...
I 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 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.
As 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.
I 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).
From what I've heard, the SSC would have had higher power, but much worse luminosity (i.e. much more noise) than the LHC.
Perhaps 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.
Perhaps. 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?
I 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.
Probably because the upgrades to the collider are so significant that it will be called the HL-LHC afterwards.
Hella Large - Large Hadron Collider?
High luminosity large hadron collider
Ho-Ly - LHC maybe.
They're collecting 10X more data, at roughly the same energy per collision.
The article says "10x luminosity", and here's what seems to be the explanation.
https://en.wikipedia.org/wiki/High_Luminosity_Large_Hadron_C...
That's the wiki article for the new one. Says "Increasing LHC luminosity involves reduction of the beam size at the collision point, and either the reduction of bunch length and spacing, or significant increase in bunch length and population."
The linked article says the new one will have "between 140 and 200 proton–proton collisions in every bunch crossing, compared to around 60 during the last LHC run." So the "10x luminosity" seems to be composed of ~3x more protons at a time along with presumably a ~3x tighter focused beam.
I had to chuckle a week or so ago when I was bumbling across the internet and landed on an article that had a link to a nutjob page where the title was something like: "CERN found something so disturbing they had to shut down immediately".
The nutjob article (yes, I did read it, LOL) suggested that they had found some universal truth maybe about God or aliens or something, and it scared them so much they just noped out of the science business to prepare themselves for the inevitable revealing of the "truth".
It is truly no wonder that so much of society is so fundamentally fucking stupid when their trusted information sources are so full of obviously false bullshit.
I can't wait until the LHC is back online zipping tiny things around the ring again in a cosmic demolition derby to find the smallest specs of our reality and give them all whimsical names.
by Tim the Particle Man Taylor
I 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-2025-0...
I 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.
I'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/fil...). Not too shaby...
All using ZFS, too
No they're not. At CERN physics data is on:
* CTA for tape storage: https://cta.docs.cern.ch/v5/
* EOS for disk storage: 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.
More 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.
Interesting, 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.
uhoh, can only store 1000 of that dataset then. D:
In one pool, sure.
You can have more than one pool.
Having 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.
The typo that sometimes got through in official literature still makes me giggle
https://www.google.com/search?q=site%3Acern.ch+%22large+hard...
https://web.archive.org/web/20170814124609/http://largehardo...
Maybe some enterprising Las Vegas citizen will jump at the opportunity to turn that idea into a hard asset.
Hopefully no sophons appear.
You don’t want an ocular alarm clock?
Hyperstrategic origami.
The 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.
Politicians 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.)
Too late, damage is already done. We have been on the wrong timeline for years at this point.
El Psy Kongroo.
Am 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…
I 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.
To be fair, if any org deserves a vanity TLD it's CERN
Yeah, given that the web was basically invented there, it seems pretty reasonable
CERN is so big that they have their own IXP: https://cixp.net/
Also, the web was invented at CERN, so like the other comment said, if someone deserves at gTLD is them.
It's a brand gTLD, like .microsoft and .google. https://en.wikipedia.org/wiki/Generic_top-level_domain#Brand...
bad timing with the price of RAM and NAND
Maybe 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...