The fathers of Cern, the European laboratory for particle physics near Geneva, which was conceived in the late 1940s, had two aims. The first was to enable the construction of large facilities that are beyond the means of the members individually. The second was to show that countries that had recently been at war could work together, and build bridges between them. These aims were shared by the founders of Sesame, which is also an accelerator-based facility, albeit on a much smaller scale with very different scientific goals, based in Jordan. The scientific and political benefits of these projects were fulfilled, but they are currently under threat. Political factors have led Cern’s governing body to close the door to Russian scientists. Remarkably, Sesame has continued to function although some of its members, which include Iran, Israel and Palestine, and also Cyprus and Turkey, are in states of conflict. But, unfortunately, it has suffered seriously from sanctions which have prevented Iran paying its dues. Meanwhile, the benefits of some other forms of scientific collaboration, such as that which enabled data sharing between Russian and other scientists studying the warming in the Arctic, which has a global impact on the climate, are being lost.
At the heart of Cern’s flagship project, the Large Hadron Collider (LHC), there is a roughly circular tunnel 27 kilometres in length housing powerful electromagnets steering bunches of protons around the ring in opposite directions. These protons are brought into head-on collision at the centre of giant detectors, which physicists use to analyse the debris of the collisions, in a quest to understand better the constituents of matter and the forces that control their behaviour, and cast light on how the universe evolved into its present state. Only 91 of Cern’s 2,769 permanent staff are research physicists. They work in collaboration with other physicists visiting temporarily. There are currently 7,866 users with home bases in Cern’s 25 member states, and 4,532 based in 58 non-members, who contribute to the cost of the detectors.
Throughout the Cold War and after, Cern was a model for sustaining humanity’s shared scientific interests in spite of politics. Russians had been working at Cern since the 1960s, while some European scientists participated in experiments in Russia. But following the invasion of Ukraine in 2022, Cern’s governing body decided not to renew the collaboration agreement with the Russian government that allowed scientists affiliated to Russian organisations to work at Cern.
Barred doors have harmed the careers of these scientists, whose fluctuating numbers peaked at around 800, and it has damaged Cern as Russia was contributing hardware as well as manpower to the ongoing upgrade of the LHC. It has also ended human contacts that lead to better mutual understanding, which are particularly valuable in times of conflict.
This value is exemplified by a story told by a Pakistani physicist who wanted to take a group of technicians to work in one of the big collaborations at Cern. They demurred as it would involve working with Israelis, but he insisted. After a few weeks they came to him and said that they were impressed by the Israeli technicians’ skills, and they were “nice guys”. Collaboration builds professional respect, which breeds tolerance of other people’s beliefs.
The LHC is the first genuinely global high-energy physics project in terms of the experiments. The experimental collaborations attract expertise from around the world, and contributions from non-member states (nms) enabled the construction of better detectors than would otherwise have been possible. The collider itself cannot be regarded as a global project: certain nms made useful contributions to its cost, but the bulk came from the member states (ms).
Following full exploitation of the LHC, Cern aspires to build a much larger collider in a new 90 km tunnel, which would (like the LHC tunnel) house an electron-positron collider (that would produce Higgs bosons in unprecedented numbers), followed by a proton-proton. This Future Circular Collider (or FCC as it has been called) will be supported by existing infrastructure, which would make it much cheaper to build at Cern than anywhere else in the world. Nevertheless, with a price tag for the material cost of the first stage of some 11.6 billion Swiss francs ($14.3 billion), it could not possibly be funded from the members’ regular contributions, which amounted to 1.2 billion francs in 2025. The hope of obtaining the missing funds from all the non-member countries whose physicists work, or in the case of Russia would like to work, at the LHC has been jeopardised by the invasion of Ukraine and other political developments. However, many countries not affected by these developments could contribute, the European Union may provide some funding, and Cern has so far obtained pledges from philanthropists to provide 0.86bn CHF. I hope this will allow mankind’s age-old quest to understand the laws that govern the universe to continue.
Sesame, whose members are currently Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestine and Turkey, today has 2,315 registered users, of whom 1,893 have home-bases in the eight members. The rest are based in 65 other countries, and there is a budget-constrained staff of 69 (which is not enough). The users stay in the on-site hostel (which was funded by Italy), and speak over meals and on shifts if working on adjacent experimental stations. Officials of the members and observers meet at the Sesame Council.
At Sesame’s heart is an electron accelerator 133 metres in circumference. As the electrons are steered round the ring, the electric field that (as we learn in school) surrounds all electrically charged particles cannot respond instantly as their directions change. Some of the energy in this field keeps going straight-on resulting in a cone of electromagnetic radiation that is emitted tangentially to their orbits. This ‘synchrotron-light’ is focused on materials, enabling studies on scales from atoms to viruses, including some of particular interest to the Middle East, for example on diseases that are prevalent in the region and agriculture, and archaeological artefacts. There are some fifty synchrotron-light sources in the world but Sesame is the only one in the region. Many have higher energy, which allows them to reach shorter distance scales. But Sesame is a 3rd generation facility, meaning that it is equipped with special devices that enhance the emission of radiation, and is capable of doing Nobel Prize winning work.
Apart from sanctions which have prevented Iran contributing to Sesame, political issues have only threatened the working of Sesame on a few occasions. The most serious was when Israeli commandos intercepted a Turkish ship taking aid to Gaza on May 31, 2010, while the Sesame Council was meeting in Cairo. This provoked strong feelings, but wise words from the Turkish delegate eased the tension. The major problem that Sesame has faced is a lack of funds. Members joined without expecting to pay construction costs. When I became involved as Sesame’s president in 2008, there was a design and a building but no money to put anything in it. It got built anyway, thanks to Iran, Israel, Jordan and Turkey agreeing to contribute $5 million each, in addition to their regular contributions (Egypt would likely have joined in, but the responsible minister changed while the special contributions were being agreed; this was the only direct impact on the project of the 2011 uprisings across much of the Arab world), and there were also cash and in-kind contributions from observers, especially the EU, Germany, Italy, Switzerland and the UK, and extra contributions from Jordan.
Yet, because of sanctions, Iran was not only unable to pay its special contribution but also owes $10.5 million in regular contributions – a major sum relative to the current annual budget of $6.6 million, of which typically only a fraction is actually paid, because members with small science budgets often struggle to meet their commitments. Nevertheless, in 2017 the ring came into operation and was opened by King Abdullah II. Experiments began the next year. So far, these have produced more than 170 publications in journals with relatively high impact factors. Sesame is only able to operate at all thanks to the provision of a solar power plant by the EU, which between March 2019 and 2026 saved the organisation $22.6 million and made it the only accelerator laboratory in the world powered entirely by renewable energy.
More members are being sought, as is philanthropic funding, that would allow Sesame to reach its full potential. More workshops, staff and beamlines are needed, and additional funds to support users’ costs when they visit Sesame would be helpful. Of course this assumes the members are willing to set differences aside and to continue to co-operate, but given Sesame’s survival so far I expect this to happen.
Cern and Sesame, which involve collaborations to build and use large facilities, are suffering from political developments, but are surviving. There are many other forms of international scientific collaboration, some of which are faring worse. Among the most consequential for our civilisation is one that involved Russian and western scientists sharing data on sea-ice and methane emissions from thawing permafrost in the Arctic. This practice has largely ended since the invasion of Ukraine. And this matters. What is happening in the Arctic, which is warming three to four times faster than the global average, plays a disproportionately large role in climate forecasting globally as it influences sea-level rise, weather patterns, carbon cycling and ecosystem stability worldwide.
The stakes, then, are high. Political tensions have been a feature of our world since time immemorial, and scientists are no strangers to them. But as our capabilities advance, the opportunity costs of preventing or delaying collaboration are growing. It is, therefore, more important than ever to encourage and facilitate scientific co-operation, even between regions in conflict, so that its multiple benefits are not lost.
