A replica of the NeXT machine used by Tim Berners-Lee in 1990 to develop and run the first WWW server, multimedia browser and web editor. This became one of CERN's first open-source projects.

Measuring Open-Source Impact with Software Heritage

We have an exciting opening for a student for 12 months, starting still in 2024: tracing CERN's impact on open source together with the Software Heritage organization. Together with our experts from CERN's Scientific Information Service and other members of the Open Source Program Office, you will discover how to measure CERN's contributions in the world of open-source software. We don't expect you to be an expert when you start, but we would love to go on this journey together! If you are a bachelor or master student, before the master graduation, then please consider contacting ospo-team@cern.ch.

As part of their work at CERN, physicists, engineers, and computer scientists take part in thousands of open-source software projects. Some of these projects are originating at CERN, many are not maintained at CERN. But how much does CERN give back to society through open-source - can we measure this? Software Heritage maintains a database of virtually all open-source software in the world. We will analyze this archive to find CERN's traces, from decades ago until today. We will discover how to do this together, including all the questions we would want to ask! Tracking, measuring, and evaluating the impact of CERN contributions on the open-source ecosystem are essential to provide CERN management and funding agencies with an indication of the returns to society.

We are looking for a student in Computer Science or similar fields, with some experience in data analytics, be it with Python, C++, Julia, or even Rust.

Please send your CV here!

The collaboration has also made publicly available the software that it developed to search for the unique particle

As part of its continued commitment to making its science fully open, the CMS collaboration has just publicly released, in electronic format, the combination of CMS measurements that contributed to establishing the discovery of the Higgs boson in 2012. This release coincides with the publication of the Combine software – the statistical analysis tool that CMS developed during the first run of the Large Hadron Collider (LHC) to search for the unique particle, which has since been adopted throughout the collaboration.

Physics measurements based on data from the LHC are usually reported as a central value and its corresponding uncertainty. For instance, soon after observing the Higgs boson in LHC proton–proton collision data, CMS measured its mass as 125.3 plus or minus 0.6 GeV (the proton mass being about 1 GeV). But this figure is just a brief summary of the measurement outcome, a bit like the title of a book.

In a measurement, the full information extracted from the data is encoded in a mathematical function, known as the likelihood function, that includes the measured value of a quantity as well as its dependence on external factors. In the case of a CMS measurement, these factors encompass the calibration of the CMS detector, the accuracy of the CMS detector simulation used to facilitate the measurement and other systematic effects.

A likelihood function of a measurement based on LHC data can be complex, as many aspects need to be pinned down to fully understand the messy collisions that take place at the LHC. For example, the likelihood function of the combination of CMS Higgs boson discovery measurements, which CMS just released in electronic format, has nearly 700 parameters for a fixed value of the Higgs boson mass. Among these, only one – the number of Higgs bosons found in the data – is the physics parameter of interest, while the rest model systematic uncertainties.

Each of these parameters corresponds to a dimension of a multi-dimensional abstract space, in which the likelihood function can be drawn. It is hard for humans to visualise a space with more than a few dimensions, let alone one with many. The new release of the likelihood function of the CMS Higgs boson discovery measurements – the first likelihood function to be made publicly available by the collaboration – allows researchers to get around this problem. With a publicly accessible likelihood function, physicists outside the CMS collaboration can now precisely factor in the CMS Higgs boson discovery measurements in their studies.

The release of this likelihood function, as well as that of the Combine software, which is used to model the likelihood and fit the data, marks a new milestone in CMS’s decade-long commitment to fully open science. It joins hundreds of open-access publications, the release of almost five petabytes of CMS data on the CERN open-data portal and the publication of its entire software framework on GitHub.

Find out more on the CMS website.

CERN launches its Open Source Program Office to help you with the release of your software and hardware designs

Have you ever considered making your software or hardware designs publicly available? Sharing your work with collaborators in research and industry has many advantages, but it may also present some questions and challenges. To help you with all issues relating to the release of your software and hardware designs, we are launching CERN’s Open Source Program Office (OSPO).

In our community, it is common practice to publish open source software and hardware designs. By releasing your work under licences that allow others to use it, study its source code, redistribute it and share improvements, you can promote transparent and inclusive research practices. Given that all our research is a collaborative effort, open source is a common way of making our software and hardware accessible to everyone, allowing us to grow through contributions and new partners.

But how easy is it to publish open source designs? While there are many advantages to releasing open source software and hardware, it also presents challenges, such as addressing intellectual property rights by choosing the right licence. The effects of licence choices on future collaborations are not always obvious and must be carefully considered. Additionally, you may be confronted with technical challenges in ensuring that released material can be effectively used and modified by others. 

Why an Open Source Program Office?

The OSPO will support you, whether you are a member of the personnel or a user, to find the best solution by giving you access to a set of best practices, tools and recommendations. With representatives from all sectors at CERN, it brings together a broad range of expertise on open source practices. If you would like to get in touch with the OSPO, you can contact us via Open.Source@cern.ch. As well as supporting the CERN internal community, the OSPO will engage with external partners to strengthen CERN’s role as a promoter of open source. 

Open source is a key pillar of open science. By promoting open source practices, the OSPO thus seeks to address one of CERN’s core ambitions: sharing our knowledge with the world. Ultimately, the aim is to increase the reach of open source projects from CERN to maximise their benefits for the scientific community, industry and society at large.

We launch on 28 November – join us!

We are organising two events, on 28 and 29 November, to officially launch the OSPO. On the first day, we will host distinguished open source experts and advocates from Nvidia, the World Health Organization and the Open Source Hardware Association to discuss the impact and future of open source, followed by an aperitif. Seats are limited – please register in advance: https://cern.ch/ospo-1.

The second day will be dedicated to the role of the OSPO within CERN; the new office will be driven by engagement from the CERN community and will strive to meet its needs. We will briefly present the plans for the OSPO and listen to your ideas, questions, projects and concerns. Please join us on this occasion: https://cern.ch/ospo-2. You are welcome to submit your questions before the event on our forum: https://ospo.web.cern.ch/tag/opening-event.