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See, collaborating on high-energy physics can be fun.
Image: CERN

A physics lab near Geneva, Switzerland, needed to coordinate thousands of high-energy physicists hurling protons at nearly the speed of light. Gathering them together for regular face-to-face meetings was impossible. Conference calls would descend into chaos.  

Instead, the European Organization for Nuclear Research, CERN, solved a problem now facing many after the coronavirus forced more than 1 billion people into lockdown: How do you coordinate a remote workforce scattered around the world?   

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Since the mid-2000s, the physicists at CERN have used a videoconferencing platform they built themselves to coordinate work on the subterranean Large Hadron Collider (LHC). The LHC is one of the world’s most powerful instruments to study the building blocks of the universe. By smashing together atomic particles in a vacuum-sealed ring 27 km (17 miles) around, it generates enormous amounts of energy—and data—as researchers closely track the subatomic bits ricocheting within (pdf). 

Revealing what the universe is made of at CERN.
Image: Maximilien Brice/Julien Ordan/CERN

But making sense of all that information requires an unprecedented degree of collaboration. In the physics world, papers coming out of LHC have become famous for their sheer number of contributors. A 2008 LHC paper included a record 3,000 authors—until 2015, when a paper in Physical Review Letters identifying the precise mass of the Higgs boson clocked in with 5,154. 


An editor of the journal at the time, Robert Garisto, said coordination among thousands of members was surprisingly smooth. “I was impressed at how well the pair of huge collaborations worked together in responding to referee and editorial comments,” he said.  

That was in large part thanks to Vidyo. 

Before Zoom, there was Vidyo

CERN started prototyping software in the mid-1990s to allow its 18,000 scientists, staff, and affiliates to work together across continents. The laboratory clearly saw where video conferencing was going, as it noted in a 2014 conference paper: “Any device in any network can be used to collaborate, in most cases with an overall high quality” over broadband, WiFi, and 3G.

Early video services, like the world wide web itself, were built by researchers in laboratories and basement server farms pushing new technology to the limit. CERN started Indico, its first software to manage scientific conferences, in 2002, and it quickly evolved to support events of all sorts and daily collaboration across research institutes. In 2009, Indico supported 23,000 virtual events.


It later integrated a video conferencing service called VRVS built by the California Institute of Technology (later renamed EVO) and then a commercial service called Vidyo in 2012. Just a few years later, more than 18,000 high-energy physicists were holding 3,200 meetings per month on the service. Physicists reported being satisfied —77% gave it a positive rating in a peer-reviewed article (of course) about the system.  

In the age of Zoom and Slack, these may seem like small feats. Since the coronavirus pandemic, use of these services has soared. Zoom is up to more than 200 million users from 10 million in just three months. Chat and communications apps Slack and Microsoft Teams are now handling 12 million and 44 million daily active users, respectively.

But at the time, CERN’s homespun system logged more meetings than comparable commercial options. It solved technological problems we’re still working out today: synching across multiple devices, video signal compression, and coordinating speakers’ presentation materials. The dissatisfaction with many of today’s conferencing systems—”confusing software, subpar hardware and the awkwardness of still-developing social norms”—makes it even more interesting to understand what CERN figured out in those early days. 

Lessons learned 

A lot has changed since the early days, says Thomas Baron, a software engineer leading CERN’s collaboration technology efforts. He has helped turn CERN’s internal tool—including Indico—into an open-source product anyone can use.


Like everyone else, Baron wrote, CERN is straining to scale up service for its collaborators amid the pandemic. Interactive meetings that once held 1,200 people now include more than 2,000 as the coronavirus clamps down on scientists’ movements. To help everyone new to large-scale virtual collaboration, Baron sent a few tips by email (lightly edited for length):

Prepare for vastly diversified use cases for video conferencing: “Online meetings were back in 2014 mostly work meetings. Now we can see new use cases, such as virtual visits of the CERN premises, physics masterclasses for worldwide students, even Zumba courses for a CERN clubs! One use case that I did not see until very recently but is bound to develop with the current virus situation is fully online scientific conferences. I have recently been contacted by organizers of such events who had to cancel the physical meeting but want to switch to a fully virtual experience.”

Solve the organizational challenge: “The challenge I see is not so much technical anymore. Current videoconference or webinar services can easily cope with the load and provide useful features to handle these events. It’s more organizational: In particular, it will involve important training for moderators and speakers who may not be all acquainted with these online processes.”

Participants’ education is crucial:  ”Attending and interacting in meetings of that size requires absolute respect of the announced etiquette, obviously starting with muting oneself when not speaking.”


Connection flexibility is paramount: “People connect to these meetings from very diverse locations and situations so the underlying videoconferencing service should provide as many connection options as possible, at least desktop clients on Windows, Mac and Linux, mobile clients from Android and iOS, calling in by phone, as well as connecting H.323 or SIP room codecs.”

Provide a simultaneous webcast: “We also regularly run for the largest meetings a webcast in parallel to the fully-interactive videoconference session. This is an additional option that many people choose, either because they can’t or don’t want to connect to the interactive session. This can also be complemented with an external chat service which bridges the webcast and interactive platform.”

Information management is fundamental for the success of the event (physical or virtual): “Large events usually follow a precise timetable that is hosted on a web site; maintaining this timetable, with all information related to each presentation and speaker, possibly with the content itself (slides or papers) can be really challenging for the organizers. For this reason we use Indico to host all the meeting data and metadata and provide a tight integration with the online platform. That way we make sure that all the information is constantly up-to-date and published to the benefit of all participants.”

Correction: CERN created its own virtual conference and event software, but integrated third-party services for video conferencing. Vidyo was not created by CERN, but is a commercial videoconferencing application integrated into CERN’s event platform, Indico.