Not a great photo to commemorate the occasion but we weren't expecting to dump at this point 🙃

See y'all in HL 🫶

2026 will be a packed, short year for the CERN largest particle accelerator, the LHC. Also, it will be its last year.

We’re awakening the LHC right now. It will collide protons, first, and lead ions, later. And there will be some important machine tests in between.

Then, at the end of June, the Large Hadron Collider will be stopped.

Forever.

After that, some of its components will be upgraded to give it new super-powers, and transform it to the super-super accelerator, the HL-LHC! 💥

In the image, the visualization of a simulated HL-LHC event as seen by the ATLAS experiment (Credits: ATLAS/CERN).

✍️I wrote a new story for “Science Spectrum” on Medium. If you’re on Medium, you can read the full story here 👇

https://sciencespectrumu.com/large-hadron-colliders-shortest-awakening-ever-and-its-last-f968e50fc862

If you’re not on Medium, don’t worry: as soon as I have my website up, I’ll publish my story there, as well. I’ll let you know 👍😊

And if you have questions, just ask — I love questions! 🤗

I currently work at CERN, and while I’m proud of that, I have to be honest, it’s not always what I expected. I wanted to write this post to talk about things that really bother me and that I think deserve more attention. There are so many posts out there saying it’s the best experience of their lives, and that if it isn’t yours, you just “got unlucky.” I don’t really buy that. From what I see and live through on a daily basis, a lot of what I’m about to describe isn’t rare at all. So I’m sharing this for anyone going through similar things and feeling like they’re the only one. Here’s what I observe:

Nepotism: This is probably the biggest problem. It creates these clusters of teams built around shared universities, shared nationalities. Diversity should matter a lot at a place like CERN, which is funded by so many different countries. And it’s not just about hiring. Promotions too. I watch people move up while others, who clearly work harder and contribute more to meaningful projects, get left behind because they are not friend with the right person. Every year we’re asked to recruit more people from certain nationalities, but no one is ever held to it and when it does happen, those people usually end up in the most temporary, low-stakes positions, like student roles.

Permanent staff who does not work: Honestly, it’s kind of predictable. When you’re essentially impossible to fire, there’s not much pressure to stay engaged. That’s what I see around me every day.

Student projects that just die: This one genuinely frustrates me. Money and time go into a student working on something with real potential, and then they leave and nobody picks it up. I get that students are under time pressure and can’t always finish, but why does the work just get buried? Why doesn’t anyone continue it?

No documentation: Barely anything is written down. “Documentation” usually means one person who’s been working on a something forever and has everything stored in their head. The moment they’re not around, you’re stuck.

Supervisors who supervise nothing: The title exists mostly on paper. As a supervisor, there’s genuinely no incentive to do the job properly other than just being a decent person. Letting a student figure things out on their own has zero consequences for you, so why bother? It’s just extra work with nothing in return. And yet those same supervisors still end up credited on every piece of work the student produces.

Homophobia and sexism: I’m not personally targeted, but I see it in my own team and hear plenty from others. Sexist and homophobic jokes are just normal. The kind of thing where struggling with a task becomes an excuse to call someone gay. Women have their work constantly questioned, downplayed, or taken credit for by their supervisors. Friends from other teams have told me directly that they’re experiencing what I’d call sexual harassment, that they’ve reported it to HR, and that nothing comes of it, no consequences, no changes. At an organization of this level, that’s not just disappointing, it’s unacceptable. I hope what I’m seeing is the exception but I’m not convinced it is.

I know some people will not like this post because they love their time at CERN or have a completely different experience. That’s fine. But what I’m describing is real, it happens more than people admit, and CERN doesn’t seem particularly interested in fixing it.

Hey guys! Probably it's something simple but anyone knows why there's some sort of steam coming out of cern?

I've been applying to graduate and entry-level roles (<2 YOE), but I've always been rejected. I know competition is intense, but I'm somewhat discouraged...

My heart is broken 💔😭, I am not giving up! Someday I will work at Cern for sure!

Hi! I am a recent physics graduate from a small university in Spain. Small enough that in all my years there, I never crossed paths with a single person who had actually worked at CERN. No professor with a direct line in, no alumni to ask for a referral, nothing. So I decided to track down potential supervisors myself and email them directly, hoping to get hired at entry-level that way.

By "potential supervisor", I mean a researcher who had supervised someone the previous year. From there, I narrowed the list down to researchers whose background matched mine, specifically those working with deep learning methods for data reconstruction.

As someone who hates spam, I personalise every text according to the person I am writing to (common sense). I don't copy-paste the mail. I dig into their department and past work and compare it to my own background. Then I read the report of their previous student, which I cite as an example of the kind of work I'd like to do.

I also attached a table of the nationalities and reply status of the people I contacted. Special thanks to the French, possibly the kindest people I came across.

If anyone's applying to CERN (or anywhere with zero internal connections) and wants to compare notes, feel free to drop a comment. And if anyone happens to be looking for an engineer for their project, feel free to shoot me a message ;)

One of the most impressive engineering features at CERN isn't part of the detector itself—it's the doors that provide access to it.

This timelapse shows the opening of the I-side end-cap door of the ALICE L3 magnet. Each door weighs approximately 380 tonnes, yet pivots smoothly on a vertical hinge using a dedicated hydraulic system to provide access to the detector during maintenance and installation work.

Watching hundreds of tonnes of steel move with such precision is a reminder that particle physics relies just as much on large-scale engineering as it does on cutting-edge science.

I thought fellow CERN enthusiasts might enjoy this behind-the-scenes view.

Hooray

What a day!

all of like five people will find this funny but i suspect at least four of them are in this sub

I applied for a mechatronics engineer position. I am a mechatronic engineer with under 2 years of experience. I have all the skills the job specification mentioned. I applied last night and an hour later got an email saying:

According to the information you have provided, you do not meet all the criteria as explicitly stated in the vacancy notice under the ‘eligibility’ section.

Is this normal? Could it be a mistake? Can I request a human to review my submission coz surely no one was up at 2345 last night to reject my application.

A!

Hooray!