Special Leiden European City of Science 2022 (ENG)

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European City of Science Leiden2022

YOUR EVENT IN THE CITY OF SCIENCE Ever since the first university of the Netherlands was founded in Leiden, the quest for knowledge has been engrained in the soul of the city for centuries to come. In its long history of being a city where science has been celebrated, Leiden today truly has become a city of science. This makes Leiden the perfect destination for your scientific conference or event.

The dedicated team at the Leiden Convention Bureau can help you with any request you have, to make sure your conference, event or meeting will be a great success. The Leiden Convention Bureau works together with all partners in the city to ensure the best outcome for your event. Discover the opportunities of our region. We are ready to support you! leidenconventionbureau.nl


COLOPHON About this publication This special was created by the editors of New Scientist on behalf of the Leiden European City of Science 2022 foundation. Leiden European City of Science 2022 Meta Knol (director), Lucien Geelhoed (editor-in-chief), Danielle Vreeburg ­(managing director), Ellen Simons (financial manager), Eva van Ekdom (communications manager), Ferry Breedveld and Corinne Hofman (ESOF champions), Marjo Buijs (EUCYS coordinator), Roosmarijn van de Velde (New European Bauhaus frontrunner) Wendy Frigge (ESOF coordinator), Chris Jaeger (Kennis door de Wijken project manager), Maja Henwood (Kennis door de Wijken project officer), Chel Bastiaans (editor), Bahador Fatemi (multimedia editor), Yanti Danoekoesoemo and Hanne Riekerk (science communicators), Sahra Almahmood (office manager) Publisher Veen Media B.V. Editor-in-chief Jim Jansen Final editor Jean-Paul Keulen Contributors to this issue Pepijn Barnard, Bram Belloni, Bob Bronshoff, Martijn van Calmthout, Mirna van Dijk, Ype Driessen, Marleen Hoebe, Cait Kennedy, Peter de Jong, Katinka Polderman, Maaike Putman, Dorine Schenk, Wouter Schreuder, Ionica Smeets, Pascal Tieman, Sebastiaan van de Water Basic design Sanna Terpstra (Twin Media bv) Design Donna van Kessel (Twin Media bv) CONTACT NEW SCIENTIST Mail redactie@newscientist.nl (for press releases), info@newscientist.nl (for editorial questions only), klantenservice@newscientist.nl Tel +31(0)85 620 2600 Address (post and street address) Oostenburgervoorstraat 166, 1018 MR Amsterdam Brand manager Thijs van der Post (thijs@newscientist.nl) Marketing and sales Alex Sieval (alex@newscientist.nl) Printing Habo DaCosta bv ISSN 2214-7403 The publisher is not liable for damages as a result of printing and typesetting errors. COPYRIGHT Nothing in this publication may be copied or stored in a database or retrieval system in any way without the written permission of the publisher. The publisher has endeavoured to fulfil all legal requirements relating to the copyright of the illustrations. Anyone who is of the opinion that other copyright regulations apply, may apply to the publisher.

From Einstein to Eveline Crone I sometimes get the reproach that I rarely leave Amsterdam or even that I leave Watergraafsmeer, my part of town, as little as possible. There is some truth in that. The hospital where I was born, my parental home and the place where I live now, are not more than 2 kilometres apart as the crow flies. Wisdom comes with age, you learn as you go, or choose your own proverb, but I have been leaving my postcode area more and more frequently and I often take the train to Leiden. When it comes to top science and research, this is the place to be, so it is not surprising that this city has been ­chosen as the European City of ­Science. From Einstein to Eveline Crone, who hasn’t walked around Leiden, I sometimes think to myself. In 2022, science will be celebrated in the ‘Key City’; activities will take place every day.

Interviews 06 ‘City of know­ ledge since 1575’ Meta Knol

and Lucien Geelhoed on Leiden2022.

14 ‘I was always visually ­inclined’ Physicist

Robbert Dijkgraaf on science and art.

16 ‘No particle without inter­ actions’ Theoreti-

cian Carlo Rovelli presents his take on the quantum world.

Professors José van Dijck, Tamara Witschge and Peter-Paul Verbeek on the desire to know.

26 ‘I bluffed my way in’ ‘Adolescence scientist’ Eveline Crone looks back on her career so far.

28 ‘Another 50 years of ­patience’ Accord-


32 ‘We must move away from perpetual growth’ Economist

European City of Science Leiden2022


Jim Jansen

Editor-in-chief New Scientist jim@newscientist.nl @jimfjansen (Twitter)

Focus 20 ‘Knowledge is power and wonderment’

ing to astronomer Ewine van Dishoeck, we will know whether we are alone within this century.


To get you warmed up, we talked to the very best scientists. We presented them with big questions upon which they and their colleagues can shed some light. I hope you enjoy reading this magazine and, even more, I hope to meet you somewhere in 2022; not in the Watergraafsmeer, but in L ­ eiden.

04 Epicentre All

year, there will be activities as part of Leiden2022. This wall gives the organisers an overview.

09 Decision tree

Do you know what you don’t know? Cabaret artist Katinka Polderman leads you to the answer to this question.

24 Healthy habits

It would be best if everyone had their own lifestyle coach, says health psychologist Andrea Evers.

More... 10 Five talents Five top Dutch experts in various fields answer five big questions.

18 The 22 of 22 These endlessly interesting questions are central to Leiden2022.

30 Photo comic

Ype Driessen and Ionica Smeets take a mathematical walk through Leiden.

34 Driving forces

Five of the countless people who work behind the scenes for Leiden2022 are placed in the spotlight.

Kate Raworth explains what she means by her doughnut economy and how it should work.

Leiden2022 | New Scientist | 3


Epicentre This studio is the epicentre of Leiden ­European City of Science 2022. For the first time, a European city will host a 365-day science festival, brimming with science, knowledge, arts and craftmanship. The ­programme is designed for anyone with a curious mind. With the help of many scientists, citizens and representatives of social and cultural organisations, every day has been given its own topic. All days have a QR code that will show you the events that are taking place. A tear-off calendar was made of all of them together. The co-­creation of 365 easily accessible, curiosity-provoking

subjects is the basis for Leiden European City of Science 2022, connecting science and society. The aim of this approach is to introduce ­science to people who would normally not come into contact with it, and to do so in an accessible way. The organisers believe that although many people have an intrinsic interest in science, for many it is never encouraged. By including art in the programme, they want to further stimulate this curiosity in a playful, unexpected way. The wide range of themes and activities means that there is something of interest

for everyone. The events range from ­scientific conferences to entertaining festivals. Also, the target audience of the events varies from very local to global. The events with an international target audience take place during European hotzones, representing the European dimension. This is the tenth time that a city has held the title of European City of Science and has organised the accompanying EuroScience Open Forum, but it is the first time that a full year of activities has been linked to it. ­Leiden has set the bar high for its successors. Text: Wouter Schreuder


‘ Leiden will be the platform­ for every curious ­Einstein’

This year, Europe is celebrating 365 days of ­curiosity. Leiden European City of Science 2022 guarantees a ­programme with international allure, connecting ­science and society. Meta Knol and Lucien Geelhoed, the ­director ­and the editor-in-chief of the annual programme ­respectively, cannot wait for the programme to start.

Interview: Marleen Hoebe and Jim Jansen Photography: Bob Bronshoff


hantasie ist wichtiger als Wissen, denn Wissen ist begrenzt’ is one of the memorable quotes of physicist Albert Einstein. Translated into English: ‘Imagination is more important than knowledge, because knowledge is limited.’ According to Meta Knol and Lucien Geelhoed, this quote encapsulates very well what Leiden, as a European science city, wishes to convey: curiosity, wonderment and imagination. In 2022, Who Knows will be the main theme of Leiden European City of Science. This theme is in line with the era of post-truth, fake news and filter bubbles. Several questions play a role in this, such as: who has the authority to judge what is true and what is not? And who knows what the future will look like? The Who Knows theme is also about the importance of asking questions. That is why 22 big, topical yet timeless questions figure prominently throughout the programme, such as: ‘What makes us human?’ These 22 questions can recur in the programme throughout the year in a variety of ways. They are a model for the importance of science and for those scientists who are working to better understand the world we live in, says Meta Knol, director of Leiden European City of Science 2022. She hopes that other people will also get to work with the questions, for example in education, by organising their own workshops. Lucien

Geelhoed, editor-in-chief of Leiden European City of Science 2022: ‘We want to be a platform in Leiden for everyone who is a curious Einstein.’ Why does Leiden make a good ­European City of Science? Meta Knol: ‘Leiden has the oldest university

in the Netherlands. From the very beginning, in 1575, it has had an international focus. For example, Leiden University has had a professor of Arabic for over four hundred years. The city has the potential – following the university’s lead – to become even more international. Leiden also has many beautiful locations where we can organise activities. It really is a festival city.’ Lucien Geelhoed: ‘Moreover, people from Leiden always make smart choices. According to one anecdote, the Prince of Orange gave the city two options at the end of the Spanish siege in 1574: no taxes for a year or a university. The question is whether this is true, but a university was founded at any rate. At the time, Leiden already aspired to become a real city of knowledge. As far as I am concerned, that is the answer to the question of why Leiden makes a good ­European science city.’ What can people expect in 2022? Geelhoed: ‘Leiden European City of Science

is one big ode to science. We are organising countless activities, from exhibitions and symposia to international conferences and award ceremonies. In addition, the year consists of three major components. We have 365 daily topics with which we will visit people in the 101 neighbourhoods in and


META KNOL studied art history at the ­University of Utrecht. After that, she was curator of modern and contemporary art at the Centraal Museum. From 2009 to 2020, she was director of ­Museum De Lakenhal. Since 2020, she has been the director of Leiden European City of Science 2022.

around Leiden. This shows Europe how knowledge can be shared right down to the very foundations of society. The second component is the EuroScience Open Forum, the largest multidisciplinary scientific conference in Europe. And then, thirdly, we have the European Union Contest for Young Scientists. In this competition of Dutch ­origin, top scientists from 14 to 24 years of age, from as many as forty different countries, come together in a grand finale. They are the Einsteins of the future, all coming to Leiden in September 2022.’ Can you give an example of one of ­those 365 daily topics? Geelhoed: ‘One of the daily topics is bats. We

believe there are many questions about bats; think, for example, of the pandemic we are currently in. We want to organise a day with Leiden2022 | New Scientist | 7


people who know a lot about bats and can answer questions about them. The goal is to go to the neighbourhood where citizen­scientists have counted the most bat species. Activities like this make the year-long ­programme hyperlocal.’ Knol: ‘We could have just called it ‘local’, but we say ‘hyperlocal’ to show the importance of equality and engagement. This local ­foundation is very important to us. Everyone can participate.’ So, visitors to Leiden and the ­surrounding area will not be ­confronted with scientists giving ­lectures on a stage? Knol: ‘No, we have two rules for scientists

participating in our local project: get out of your institute and don’t give lectures. Ideally, we would like to see them ride their bikes into town to take part in a conversation about the importance of their profession.’ Geelhoed: ‘Because scientists have to think about different forms of communication, we see different collaborations emerging. Archaeologists from the National Museum of Antiquities, for example, are now researching a grave in which pollen was found in a

honey jar that was still open when the grave was sealed. Palynologists, experts in the field of pollen, are very enthusiastic about this and want to participate in the research. This makes a subject like this interesting for a very broad audience.’ What audience do you want to reach? Knol: ‘We are targeting anyone with a curious

mind, and we want to appeal to ­people’s interests as much as possible. If you love stargazing, we don’t care if you are a child or a Nobel Prize winner. We focus on the content and quality of the encounter, not the quantity. I would rather have three people go home after a meeting thinking “I’ve never looked at it like that, how cool”, than three hundred people sitting in a room who have forgotten they were there the next day.’ Geelhoed: ‘I think our year mostly revolves around giving context to wonderment, so that everyone has the space to ask ques­ tions. That is where our Who Knows theme comes in.’ What do you want to achieve with this theme? Knol: ‘Our goal is to connect science and


LUCIEN GEELHOED has been connected to the Leiden Knowledge Region as a strategist for quite some time and has been involved in this project since 2016. In 2020, he started as manager at the ­Leiden European City of ­Science 2022 foundation, where he is now editor-­­­ i­n-chief. He is also a game ­designer.

society even more strongly. That is why we are expanding science in our programme to include knowledge, arts and craftmanship, for example.’ Geelhoed: ‘But modesty is also a virtue for scientists.’ Why must science remain modest? Geelhoed: ‘We only know a fraction of every­

thing. For example, we don’t know what happens under water in 95 percent of the oceans because we have never been there.’ Knol: ‘And we base our assumptions about the universe on only 4 percent of it. There is still a lot to be done.’ So, we should stay curious? Geelhoed: ‘Yes, it is important that we conti-

nue to wonder and leave room for chance. Chance is the foundation of science. Some­ one like Leiden biologist Lex van der Eb, who is famous among dozens, laid the founda­tion for the current corona vaccines. He came across something by chance around 1990 when he was working on something else. That chance is the pot of gold at the end of the scientific rainbow.’ 8 | New Scientist | Leiden2022

katinka polderman

Leiden2022 | New Scientist | 9

FIVE QUESTIONS for a better world

Five talents working in the Netherlands, each from a ­different field, answer five questions that will feature during Leiden European City of Science 2022. These questions are ­important not only for science, but for all curious people. And they help us think about a better world. These talents want to ­contribute to this themselves. Text: Marleen Hoebe Photography: Bram Belloni






Noel de Miranda

Principal Investigator Cancer Immunogenetics, Leiden University Medical Centre ‘It is in our nature to want to know more; not only to better understand ourselves and our environment, but also to find ­solutions to current problems. Research can lead to new breakthroughs and, at the same time, to new questions that we want to answer. This creates progress; for ­example, we develop vaccinations that help reduce mortality. 10 | New Scientist | Leiden2022

2 ‘I try to write my scientific articles to be more accessible’

Every day, millions of people engage in an infinite puzzle. All are trying to solve a little piece of the problem. So do I, as a scientist in cancer research. Not too long ago, there was a breakthrough in my field. Scientists had figured out what tools we can use so the immune system can recognise and destroy cancer cells. Patients are now benefiting from this. Unfortunately, the tools don’t work for every patient. My colleagues and I are trying to figure out how to help these patients in a different way. We think a lot about which immune cells might play a role. This is very complex, because we do not yet know how to use immunotherapy to control different immune cells. ­However, each discovery has the ­potential to become a therapy for a patient. It is, therefore, an honour for me to be able to do this research.’




Sarah Schrader

Associate Professor of Osteoarchaeology, Leiden University ‘Science today is much more open than it was ten years ago. At that time, scientists were hardly publishing in open access journals that can be accessed online free of charge. I couldn’t afford to publish in such journals eight years ago either. There was no money for it. Some research fields feel that open-access journals have less prestige. Within my field, we encourage scientists to publish in these journals. At Leiden

University, we have that option because the university has agreements with various publishers. More and more universities are doing this, but it is still not enough. More financial investment is needed to make ­science more accessible. As a scientist, you yourself can also do something. I try to write my scientific articles to be more accessible. These are articles about research on human bones. By examining bones, I can learn more about the lives of people from the past, such as what they ate, whether they had diseases and whether they were immigrants. I can even find out if someone had a high or low socioeconomic status. One of my studies of four-thousand-year-old bones shows that status had an impact on people’s health even then. For example, people with low socioeconomic status could not go to the doctor and ate less healthily. I want to look at how that knowledge can help ­­counter health inequalities today.’ Leiden2022 | New Scientist | 11

five questions




Meike Kombrink

PhD candidate at the Netherlands Forensic Institute ‘I believe our brain in particular makes us human. The fact that this works so well sets us apart from animals and artificial intelligence (AI). Our brain is small and efficient. AI also tries to work well and efficiently but cannot do so without an extremely large numbers of computers. We humans don’t need that much space for our brains, yet







Aoife Fleming

Youth Representative for Sustainable Development, United Nations ‘It is certainly possible for humans, ­animals and nature to live in balance with each other, but I have the impression that this has not been the case in the Netherlands for a very long time. In some other countries you do see that balance. For example, there are indigenous peoples who protect and manage forests. We can learn from that. In the Netherlands, we assume we must keep growing and developing. But something really needs to change. 12 | New Scientist | Leiden2022


we are very good at reasoning. AI has not reached that point yet. But we can use AI for other things. In my research, I am now investigating whether we can intercept steganography with AI. Steganography is the hiding of messages in, for example, a photograph or video. We cannot see these messages. For example, there may be a very small colour change that is only visible when we start examining the bits of an image. And we cannot do that ourselves; we need a computer to ­process that information. The interesting thing is that we don’t know yet how common steganography is. That is because we have to look for something hidden. I hope eventually to be able to intercept steganographic messages and develop a method that makes it possible to collect useful evidence for court cases.’

I believe there are several ways we can live more sustainably. Young people can play a role in this. Together with other youth representatives, I researched what young people from different countries see as obstacles on the road to climate action. This revealed that there is not yet enough knowledge about sustainability available. Countries could solve this by offering more studies on sustainability. The questionnaires also showed that it is often difficult for young people to raise money if they want to start sustainable initiatives, because this money usually goes to companies. I am now working with fellow representatives to get the International Court of Justice to give countries a recommendation on what they should do to protect future generations from climate change. This advice will help these countries to become more ambitious and to take action. I hope that in 2030 we can look back with a good feeling and can say that we are on course for a climate neutral world.’



Angelo Accardo

Assistant Professor of Precision and Microsystems Engineering, TU Delft TU Delft does its best to promote equal opportunities for men and women. The number of male researchers is high – this is more often the case at technical universities – but more and more women are joining the ranks. This is partly due to the Delft Technology Fellowship, an initiative of the university that offers appointments to ­outstanding female scientists. In addition, every scientist can qualify for a Dutch or European grant to start or

strengthen his or her career as a researcher. More and more foreign scientists like me are taking advantage of this and are joining Dutch universities like TU Delft. It is great to see. I recently received two Dutch grants for my research. I use a 3D printing method using light to create small, plastic 3D environments. In these structures, it is possible, among other things, to grow and study cells outside the human body. This helps my colleagues and me to ­better understand the behaviour of cells. We are also researching different ­therapies in these microenvironments to assess the efficacy of very recent cancer treatment methods such as proton ­therapy in the brain. In this way, we can determine what dose of protons is ­needed to destroy cancer cells. Our goal is to use these 3D models to reduce the amount of animal testing that is ­currently necessary to treat human patients.’ Leiden2022 | New Scientist | 13

‘When I write out calculations, they become part of reality’ Anyone who thought that scientists only concern themselves­ with formulas is wrong. Professor of physics Robbert ­Dijkgraaf has always been visually oriented, as he explains in the Allard Pierson Museum in Amsterdam. ‘At the art academy, I learned what doing research really is.’ Text: Jim Jansen Photography: Bram Belloni


have a special bond with the Allard Pierson Museum. This is the museum of the University of Amsterdam, in the most beautiful location in the city. A few years ago, there was a pop-up museum here and, as guest curator, I was allowed to

14 | New Scientist | Leiden2022

set up a chamber of wonders full of scientific objects that stimulate the imagination. That was a boyhood dream come true for someone like me who loves art so much. All my life, I have been visually oriented. I ­recently found my school drawings again. They looked like the writings of a sixteenth­century naturalist, with that neat handwriting and those precise drawings. For example, I made portraits of all the felines. Every

line and colour seemed to make sense. I didn’t care that I didn’t understand everything. I just thought it was beautiful. That sense of beauty has remained. When I think about scientific concepts now, I always see them very visually. With abstract concepts, I see three-dimensional figures and beautiful colours, and I get an aesthetic feeling. When I try to understand something, it is important for me to write




‘The great gift of my time at the Rietveld ­Academy was that I discovered that I was, and wanted to be, a researcher’ out the calculations myself. Only when something is on paper does it become real. It becomes part of reality instead of a quirk in my head. For me, it is a way to give my intellectual adventures something to hold on to.

Walking through this beautiful museum makes me think of Jacobus van ’t Hoff, the first Nobel laureate in Chemistry. He held his inaugural lecture as professor at the University of Amsterdam on the role of ­imagination in science. He approached the

Physicist Robbert Dijkgraaf is a professor at the University of Amsterdam and the director of the Institute for Advanced Study in Princeton, USA. In 2019, he received an honorary doctorate from Leiden University.

question very scientifically. He divided the two hundred most important scientists of his time into three categories. Those who had no interest in art, those who did and then the group who had, in his words, a ‘perverted’ imagination – who were into alchemy and astrology. The third list ­included great names such as physicist Isaac Newton, mathematician Gottfried Leibnitz and philosopher René Descartes. Van ’t Hoff made the point that curiosity, fantasy and imagination are hugely important in science. Research is about what we don’t know yet – the unknown. Art also ­begins with a blank sheet of paper. You move your pencil and enter an sea of possibilities. I spent a year at the Gerrit Rietveld Academy and that is where I learned what doing research really entails. In art school, a lot of attention is paid to exploring the possibilities. The emphasis is on the process rather than the outcome. Ultimately, it is about how successful you are at pushing yourself in different directions and ­exploring new things. This is not how our academic education is organised and more attention should be paid to it. Thanks to the Rietveld Academy, I have become a different type of scientist. Before I went to art school, I approached knowledge mostly in a passive way. I just wanted to get an A on an exam. I did, but that made me lose my enthusiasm. The great gift of my time at the Rietveld Academy was that I ­discovered that I was, and wanted to be, a researcher. I remember very well that as a Rietveld student I walked into the academic bookshop in Utrecht and thought: “I can just walk into the physics department, look at everything and choose something I feel like reading right now, without anyone expecting anything from me.” I had let the fire smoulder and there it flared up again. Science is something you have to do actively.’ Leiden2022 | New Scientist | 15

‘THE PARTICLE WORLD IS NOT A TOTALLY DIFFERENT REALITY’ According to quantum mechanics a particle is no longer in one single place, and entangled particles seem to know what state the other particle is in. Incomprehensible? Not if you accept that such particles are entirely defined by their ­interactions, argues Italian physicist Carlo Rovelli.

Text: Martijn van Calmthout Illustration: Pepijn Barnard


n his latest book Helgoland, Italian physicist Carlo Rovelli takes the reader back to the eponymous birthplace of quantum physics: a treeless German North Sea ­island where young physics student Werner Heisenberg took refuge from hay fever in 1925. He came back with a theory of the atom that we still enjoy today. But that pleasure comes at a price, Rovelli says from his study in Toronto, Canada. ‘Quantum physics has not only brought us microelectronics, computers, molecular ­biology, nanochemistry and much more. It has also brought the realisation that our intuition does not work at all in the world of the very small. Quantum reality is incomprehensible. In my book I try to show that we are beginning to understand why.’ Carlo Rovelli. Italian by birth. Theoretical physicist. A friendly sixty-something with twinkling eyes and curls. About five years ago, he became world famous with his ­bestseller Seven Brief Lessons on Physics. A reassuringly thin, somewhat ­philosophical work on what we know about the foundations of reality.

16 | New Scientist | Leiden2022

Heligoland is thicker. Even more philoso­ phical. But it is also meant to be reassuring, Rovelli says. ‘The key message is: the particle world is no crazier than the everyday world and we can deal with it like adults. It is like the modern solar system. We see the sun moving across the sky every day, rising and setting. Yet we know: it is not the sun that moves, it is us. And no one is upset about that.’ What makes quantum physics so elusive?

‘It is that we think classically about the world of particles and atoms. You cannot do that. It goes back to Heisenberg on ­Helgoland. He tried to find order in the ­energy jumps of electrons in atoms, which we see thanks to the spectral lines in their light. How could electrons make only those steps? Heisenberg found the formulas that precisely describe the process. Provided, and there the incomprehensible begins, that numbers are replaced by matrices – by grids of numbers.’ What did that insight change?

‘Everything. Quantities are no longer fixed, as with Newton; there are only transitions between states and probabilities. This leads

mathematically to particles that are no longer in one place, but everywhere. To ­entangled particles that seem to know what state the other is in. To a cat in a box that is both awake and asleep – I don’t like to kill Schrödinger’s cat. In short, the famous quantum magic. And it’s very different from what objects do in everyday reality.’ Particles that are also waves.

‘It is often put that way, yes. But an electron is not one or the other. It manifests itself as one or the other, depending on the perspective; in the interaction with the researcher.’ There are quite a lot of interpretations in physics that aim to contain the ­craziness of the quantum world. You don’t like most of them. Why?

‘Take the popular many-worlds interpretation, in which reality continually splits







Does it help physicists?

‘Certainly. The interpretation you use is not just a philosophy; it gives new form to ­intuition. I research the quantum nature of gravity, one of the great questions of physics. Of all science, I would even say. For this, a good perspective helps to ask the right questions.’ Will ordinary people ever get used to this idea?

‘IN THE EVERYDAY WORLD, IT IS NOT AT ALL SURPRISING THAT ENTITIES ARE DEFINED BY THEIR INTERACTIONS’ when a particle jumps to a particular state. The idea is that in a parallel reality it ends up in a different state. But, of course, the idea of infinite realities is at least as crazy as the indeterminacy of states. If you subscribe to it, you are anxiously trying to hold on to your classical idea about ­particles having properties – at all costs.’ In Helgoland, you make a case for what is called the relational ­interpretation of quantum mechanics. What does that mean?

‘The main point is that objects like par-

ticles are entirely defined by their interactions; by their relationships with ­other objects. A particle without interactions is invisible and untraceable. It is not there.’ That is a pretty radical position. Are you saying that objects in ­themselves do not exist?

‘Of course objects do exist. I am a physicist, a realist; I investigate the material world, stones, stars, particles. But if you are trying to understand why the particle world is so foreign to us, it is a useful idea.’

‘Quantum effects rarely play a role in ­everyday life. But in the everyday world, it is not at all surprising that entities are ­defined by their interactions. This applies to people and their relationships, to ­organisms in eco­systems, to social ­structures and even to p ­ olitics. I do like the idea that the particle world is in fact structured in the same way. It is not a totally ­different reality. We know it very well.’ Provided you find the right ­perspective.

‘You may ask yourself why a physicist should be concerned with philosophy. Apart from the fact that it fascinates me as an inquisitive person, it has always been the case that important scientists thought deeply about their basic assumptions. ­Einstein arrived at his relativity when he realised that time and distance are fundamentally dependent on the motion of the observer. Insight changes everything; that is the way it has always been.’ Leiden2022 | New Scientist | 17

European City of Science Leiden2022

The 22 big questions of 2022

Leiden2022 presents a 365-day public programme packed with science, knowledge, art and ­craftsmanship, for everyone with a curious mind. Throughout the year, 22 topical, always urgent, universal yet unsolvable, endlessly fascinating ­scientific questions will take centre stage. ­Curious? Scan the QR code!

























BE ABLE TO TIME TRAVEL? 18 | New Scientist | Leiden2022




European City of Science Leiden2022


























NO ONE FORMULATED YET? Leiden2022 | New Scientist | 19

‘Knowledge is power,

but also wonderment’ Sometimes asking questions and researching them together from different perspectives is more important than finding answers. Professors José van Dijck, Peter-Paul Verbeek and Tamara Witschge agree on this. Using four questions as a guide, we talk to them about why we want to know things and the role that science plays.

Text: Dorine Schenk Photography: Bob Bronshoff




‘My research team’s central question is: how can we use media to encourage the social change that various people and organisations in society are trying to bring about, like accelerating the sustainability transition or a more inclusive society’ says Tamara Witschge. She is a professor at the Department of Media and Journalism at the University of Groningen and lecturer in Creative Media for Social Change at the Amsterdam University of Applied Sciences. 20 | New Scientist | Leiden2022

‘Not everyone experiences the same level of involvement or ownership regarding these changes. We explore how to use media to encourage ownership and find out the needs and wishes of various communities to see how we can jointly shape the necessary social change. In doing so, I run up against the role of uncertainty in society. For collective change, we need to deal with uncertainty, because there is a lot of uncertainty. But there is social pressure to find clear answers – including from ­science. We are looking at how we can give uncertainty more space in our stories.’ ‘What my research group is working on can be summarised by the question: “How do we control digital society?”’ says José van Dijck, Professor of Media and Digital Society at Utrecht University. ‘More ­specifically, we are looking at the question of how we organise digital society in a responsible way, in which we always do

justice to public values such as privacy, but also security, transparency, democratic control, equality and autonomy? We are examining what this means for the current digital infrastructure and the public ­sectors in which we want to embed these public values.’ ‘The overarching question of my research is: “How does technology shape humans and society?”’, says Peter-Paul Verbeek, Professor of Philosophy of Humans and Technology at the University of Twente and scientific co-director of the DesignLab at the same university. ‘This question is about the effect technology has on how we understand the world, how we judge ethically and how we organise our lives. I am now working on a book about how technology is helping us to answer in a new way the questions posed by the eighteenth-century philosopher Kant: “What can I know?”, “What should I do?”,

José van Dijck

‘Asking ­questions is something ­individual, ­while at the same time being very ­universal’

“What can I hope for?”. This is about how technical instruments affect science. ­Furthermore, you can judge technology ethically, but vice versa, technology also ­influences our morality. The contrast between technology and religion is less stark than we think; technology is a kind of fate, even if we think we have control over it.’





Van Dijck: ‘This question contains a broad, general “we”, but it is very important who wants to know something. If a child asks something, it is different than if

the questioner is a scientist. Asking questions is something individual, while at the same time being very universal. That is the ­beauty of curiosity. It can be individual and driven by empathy or hunger for knowledge. But it can also be driven by a specific interest.’ Verbeek: ‘The reason why we want to know things always has an existential background; why you want to know ­something. But it often has a political ­background as well; why is it important to know? I think this comes from wonderment on the one hand – you don’t understand the world and you want to be able to understand it – and anxiety on the other hand – thanks to knowledge you are better able to handle things that bother you. Knowledge is power, but also wonderment. You can see this in citizen science. Citizens are doing science, often with political motivation. You want to know about wasteLeiden2022 | New Scientist | 21

waarom willen we weten?

Peter-Paul Verbeek




water quality or noise pollution from ­aircraft. Knowledge is a better way to put these subjects on the agenda than an ­opinion. Intrinsic curiosity is also a driving force. My father-in-law, a physicist, related how moved he was as a PhD student when a measurement exactly matched his ­prediction. That is wonderful! Reality is much greater than we understand and ­getting a little closer to it is the existential drive that also motivates many scientists.’ Witschge: ‘It is important that citizen­science projects are in line with what people want to know more about and do not 22 | New Scientist | Leiden2022

force on them what they should want to know. It is often the case that we don’t want to know what we don’t yet know. I have written articles about the importance of curiosity and empathy in science, but as a person I find that super difficult at times. For example, my mother said in March that she was not going to get a covid-19 vaccine. I started asking questions: “Why not? What information do you have?” But I didn’t want to know the answers at all. I did ask questions, but that “wanting to know what I don’t know yet”, that interest, was ­completely gone.’

Verbeek: ‘Because science emancipates and connects. A critical attitude means that you don’t take everything for granted; it means that you question assumptions and what you have always taken for granted and that you realise that things can also be different. At the same time, striving for knowledge and truth connects people, because that truth can only exist if you share it with others. This is why science is so incredibly important in our society and why we should not let it be a privilege of scientists. Everyone has a right to ­participate in this community.’ Van Dijck: ‘As American politician ­Daniel Patrick Moynihan once said: “Everyone is entitled to their own opinions, but not their own facts.”’ Witschge: ‘And everyone is entitled to questions. That is not a matter of course. Years ago, I conducted research into the online debate on migration in the Netherlands. There you see how questions are ­dismissed with “we already know that” or “that is not relevant”. Let’s look at how we can enable people to continue to ask ­questions and explore questions together, without labelling all opinions as facts. It is not about finding an answer, but about the joint search that creates a connection. ­Science can contribute to this. Not with answers, but by helping citizens and organisations to formulate the right questions.’ Van Dijck: ‘This is nicely encapsulated in the term common sense; agreeing together on what is sensible. Science is a communal and incredibly social event. It is human work, even for scientists. We work together on knowledge development. Reaching common sense is also one of the most fun things to do. It involves finding a balance between curiosity – which contains a

c­ ertain amount of excess, especially in ­children who want to know everything – and researchability – what can you actually investigate. There is also an urgency component. As a science community, we seek the right balance between those three.’ Tamara Witschge




Verbeek: ‘Most of the questions have

already been asked, but we ask them in a new way each time. Now when I ask, “what is man?”, I do so from a techno­lo­ gical context. Kant did so in a very ­different way.’ Van Dijck: ‘One can indeed ask questions over and over again. One has to, because problems are often so complex – especially nowadays – that one cannot rely on just one expertise. Take, for example, questions about energy generation or the climate debate. We need to look at this through ­different lenses, with philosophers, ­psychologists, economists, and physicists. It is precisely this wealth of perspectives that can contribute to solutions. Mutual respect of perspectives and expertise is important, as is connecting people.’ Witschge: ‘I am not so interested in what question has not been asked yet, but rather in what new ways we have not yet tried to look at existing questions. That is where the keys to new knowledge lie. We must involve different types of knowledge. And I am not just talking about different disciplines, but also about expertise from society, ­experiential knowledge, and so on.’ Verbeek: ‘I agree with that. I see this in medical research, for example, in which patients actively participate, not just to implement ideas of professors, but because they have first-hand experience of their ­illness and are therefore a unique source of knowledge for the research. They do not pretend to have the knowledge of a doctor, but together they form a community of knowledge.’ Van Dijck: ‘Perhaps a better question would be: what recurring question has never been properly answered? That partly echoes what Tamara just said. A question can be asked over and over again and be relevant over and over again, as Peter-Paul pointed out. A question you asked ten years ago can now be relevant and original again, from a new perspective.’ Witschge: ‘Or: what question is worth asking over and over again?’

Leiden2022 | New Scientist | 23




A personal coach for everyone? ‘We are living longer than ever, but we are chronically ill for much longer too,’ says Andrea Evers, Professor of Health Psychology at Leiden University. ‘This is especially the case for people from vulnerable groups, like people with a low level of education. On ­average, they live nineteen years shorter in good health because, for example, they have less access to healthy food and a green environment that encourages them to go outside and exercise. The major increase in chronic diseases such as diabetes or cardiovascular disease in Western countries is mainly due to a specific lifestyle. Some people think it is easy to make a lifestyle change, but it is actually very complicated. Evolutionarily speaking, we tend to put everything in our mouths that is fatty and sweet. Especially when stressed, our willpower fails us, and we open our refrigerator anyway. If the fridge contains only healthy food, we obviously can’t grab something unhealthy. But people who are under a lot of stress – perhaps because they are in debt or ill – often have better things to do than change the contents of their ­refrigerator. In addition, some days you will be more successful in maintaining a certain lifestyle than others. Many people let this get them down and then tend to stop making changes to their lifestyle. That is why we need to approach behavioural change in a positive way. Rewards can help; think of a free gym membership for someone who keeps eating healthy. But some are more sensitive to such rewards than others. My research group and I have developed an online lifestyle program for people with cardiovascular disease. It can help encourage people to change their behaviour at home in an easy way. However, a digital approach is not suitable for everyone. Vulnerable groups often respond better to a local approach, such as a neighbourhood coach to walk with. Actually, everyone should have a personal coach like that. They can help to find out which approach works better for someone, including by examining whether they had specific healthy habits in the past. Re-introducing old healthy habits is a lot easier than teaching someone something they have never done before.’ Text: Marleen Hoebe



‘Occasionally, I put obstacles in my own path’ Not once but three times during the career of ­‘adolescence specialist’ Eveline Crone have there been parallels between her research and her own life. ‘The question, of course, is: do I start researching something because it really occupies me? Or is my research changing me?’ Text: Mirna van Dijk Photography: Bram Belloni

Science ‘I didn’t really know what I wanted to do after high school, and I ended up in psychology more or less by accident. It was a hit; I loved it from day one. I wanted to know everything that was in those books. I was and am utterly captivated by it. We will never be able to fully understand the ­complex relationship between brain and behaviour, but I welcome every step, every piece of the puzzle.’

MRI ‘When I started out as a young researcher, just getting my PhD, I heard that there were scientists in the United States who were taking pictures of the brain while someone was performing a certain task. I found that 26 | New Scientist | Leiden2022

so fascinating! I thought: “Wow, you can really see into the brain! That’s where I have to go, I want to learn that too.” So, without thinking whether I had the right skills – I have no physics background at all – I bluffed my way in.’

Risky behaviour ‘At the time, I was very curious about the risky behaviour of young people – and my own career was also characterised by risky behaviour. They don’t say “research is ­me-search” for nothing, haha. Starting in the year 2000, I immersed myself in brain research in the US, looking at how the brain responds to getting rewards. We ­discovered that there is an area, very deep in the brain, all the way down below the cortex – we call it the reptilian brain ­because it is also present in primary animals – that is more active in adolescents than in adults. This explains, among other things, why they take risks more easily.’


EVELINE CRONE is Professor of Neurocognitive Developmental Psychology at Leiden University and Professor of Developmental Neuroscience in Society at Erasmus University Rotterdam. As head of the Brain & Development Lab in ­Leiden, which she founded, and of the recently founded Society, Youth & Neuroscience Connected Lab in Rotterdam, she and her team conduct innovative research into adolescent brain processes using MRI scans. As one of the first in the world, Crone follows young people, their lives, their thoughts and the neurological processes in their brains through the years. Her personal mission is to ­create social opportunities for young people that meet their needs. Crone is a member of the Royal Netherlands Academy of Arts and Sciences and the European Research Council. She wrote the bestseller The Adolescent Brain (2008) and has won numerous prestigious academic awards, including the Spinoza Prize in 2017. She lives with her family in Oegstgeest.

Self-image ‘At first, I was mainly concerned with the behaviour of young people, but I became increasingly interested in how they think about themselves. And, in a very funny ­coincidence: at that time, I myself was also very preoccupied with what my role is, with my identity as a scientist. After all, I had delved into a new field, neuroscience, but I was trained as a psychologist. This sometimes led to friction because people asked: “Are you a psychologist or a neuroscientist?” It seems like you always have to choose. And I also became interested in writing popular science books. Of course, no good scientist would ever do something like that.’

where I wasn’t so worried about what ­others thought of me. I just thought: I have achieved this, now what can I do for other scientists? How can I inspire young people? How can I build networks between scientists in which everyone benefits? So, that was the third time that there were parallels between my research and my own life. The question, of course, is: do I start researching something because it really occupies me? Or does something have such an effect on me because I am researching it? You may well be moving ­along with your own research. In any case, it is good to keep developing. I want to challenge myself; occasionally, I feel the need to put obstacles in my own path.’

Social behaviour


‘Gradually I expanded the focus of my ­research to prosocial behaviour. Because even though adolescents take a lot of risks, only a small percentage of them really get into trouble. Most young people develop into people who contribute something to society, who like to do good things for ­others. As a scientist, I also reached a point

‘Young people have been restricted by the pandemic in three of their fundamental needs: to discover the world through risk-taking and exploration, to form close social connections with friends, and the need to be seen and heard and to be given respect. The question is: what makes young people resilient enough to deal with

‘WHAT COVID HAS MEANT FOR YOUNG PEOPLE SHOULD NOT BE UNDERESTIMATED’ these limitations? We looked into this and found that if young people could do something to help their friends or family, such as deliver groceries, or do something that mattered in society, such as help at the testing sites, it gave them a sense of power. This really turned out to be an important resilience factor. We should cherish our young people ­because they are renewing society and ­there is a fire burning in them: they want to make the world a better place. What ­COVID has meant and still means for young people, should not be downplayed with remarks like “there are worse things”, because they will not get this time back. It is a very important and beautiful period.’ Leiden2022 | New Scientist | 27

‘Another thirty to fifty years and we will know’ Are we the only ones in the universe? Is that why it is so eerily ­quiet in our part of the galaxy? Or do alien ­creatures, lightyears away, feel the warmth of a star just like we do? Lauded Professor of Astrochemistry Ewine van Dishoeck expects that all speculation about this will come to an end before the end of the century. Text: Sebastiaan van de Water Photography: Bram Belloni



BEGINNING? 28 | New Scientist | Leiden2022


o six-toed footprint on the moon, not even a cracking signal from the dark void. In the past seventy years, astronauts and astronomers have been unable to find a shred of evidence for the existence of extra-terrestrial life. The only voice that sometimes breaks the silence around our home planet is the echo of our own unanswered question: ‘Hello, is anyone there?’

Nevertheless, Leiden astronomer Ewine van Dishoeck is not disappointed. ‘I am a cautious person. As a student, I thought: “It may take many centuries to answer that big question.” ’ Since then, she has peered through imposing telescopes built on mountain tops. She discovered how and where new planets are born. She organised conferences on the atmospheric fingerprints that life forms leave in the universe.



And just as she predicted, she and her colleagues still cannot say whether extra-terrestrial life exists or not, let alone whether it floats, swims or crawls, or whether it is multi­cellular, unicellular or noncellular. But she has since revised her original prognosis. We no longer have to wait for centuries. ‘We are really lucky. We are the first generation with the knowledge and technology to answer this question scientifically. Another thirty to fifty years and we will know.’

with its seven seas is a unique celestial body has shown to be cosmic narcissism of the highest order. ‘Water is the most ­common molecule in space,’ says Van Dishoeck. ‘We have recently discovered that in a region of space where new planets are born, there is enough water floating around for six thousand Atlantic Oceans.’ So, it is possible that the Milky Way Galaxy contains countless planets that are ­completely covered with the same stuff that falls from our sky in drops.

Cosmic narcissism

Alien brothers

Two powerful instruments are about to change the human view of space forever. In Chile’s bone-dry Atacama Desert, the Extremely Large Telescope (ELT), equipped with a 39-metre-wide mirror, is currently being built. The James Webb Space Telescope is the successor to the legendary Hubble. In addition, the next large space telescope is on the drawing board, ­designed specifically for the search for ­extra-terrestrial life, with a launch date around 2050. ‘These new telescopes will allow us to focus on the exoplanets that have been ­discovered in recent years,’ says Van Dishoeck. ‘Like the Earth-like planet orbiting Proxima Centauri, our neighbouring star.’ A little further away, but just as interesting, are three planets orbiting the star 2MASS J23062928-0502285, also known as TRAPPIST-1. What makes these planets so exceptional? That is the crux of the matter: they are not exceptional. Just like the Earth is not. The ancient notion that our home planet

This is good news, because water is the best conceivable breeding ground for ­molecules to collide and start the accident called life. That does not mean that swimming takes place on every watery planet. It does not have to. ‘A few hundred billion stars twinkle in the Milky Way alone. We now know that on average they all have at least one planet. Even if only 1 per cent of those stars have an Earth-like planet with liquid water orbiting them, that gives us over a billion potential breeding sites.’ We can tell which planets are the lucky ones by their atmospheres. Living beings are by definition biochemical factories. They take substances from their surroundings and excrete other substances. So, they leave a chemical fingerprint. ‘There are fierce discussions about what those fingerprints might look like,’ says Van Dishoeck. ‘But let me put it this way: if aliens were to look at Earth from one of the TRAPPIST-1 planets with telescopes like the ones we will be building in the coming decades, they will unmistakably conclude that they are not alone.’ It is possible that the discovery of ­extra-terrestrial life will send shock waves through our society. It is therefore timely that Van Dishoeck joined the Pontifical Academy of Sciences in the summer of 2021. She may soon be explaining to ­Francis and his cardinals what the approa­





EWINE VAN DISHOECK is Professor of Molecular ­Astrophysics at Leiden University and scientific director of the Netherlands Research School for Astronomy. From 2018 to 2021, she was President of the International Astronomical ­Union. In 2021 she became a member of the Pontifical ­Academy of Sciences. She has received many awards, ­including a Spinoza Prize in 2000 and the Kavli Prize for Astrophysics in 2018.



GO ROUND? ching discoveries can mean. ‘I hope to meet the Pope soon. I think he is pretty open to the possibility of extra-terrestrial life. He is a chemistry graduate; did you know that?’ says Van Dishoeck. In his latest encyclical, Fratelli tutti (All Brothers), the supreme pontiff already wrote that in this era in which we discover distant planets, we must not forget the needs of our closest neighbours. ‘I couldn’t agree more,’ says Van Dishoeck. ‘But I did say at the time in the Pontifical Academy: close neighbour is a relative term. Even on distant planets we may find our fratelli.’

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ype & ionica WHAT CAN’T WE



The mathematical walk

30 | New Scientist | Leiden2022



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LAST CENTURY’ We have to get rid of the idea that we have to ensure growth all the time, says economist Kate Raworth. ‘Progress comes from a dynamic balance between the environment and what we need.’

32 | New Scientist | Leiden2022




We have to move towards fewer ­possessions so there is space in the streets again for cycling, playing and ­creating connections between people

Text: Marleen Hoebe Photography: Roman Krznaric


f we want to shape the future in a ­better way, we must first realise that we need to change the global economy, as complex as that is. Our economy is still focused on growth and has been since the middle of the last century. This is partly due to the concept of gross domestic product – GDP – developed by American economist Simon Kuznets. The idea ­behind this is that an increase in this value equals economic growth. And that should mean prosperity. GDP is a very powerful tool for comparing national income across countries. But it says little about prosperity. You need more figures for that. The message of the twentieth century was to ensure continuous growth. For the twenty-first century, that message must be different. Growth is very destructive to the Earth. Progress comes from a dynamic ­balance between the environment and what we need. We have to go through a transformation. That is where the doughnut model can help. This diagram, a circle with a hole in the middle, shows whether we are meeting people’s basic needs and whether in doing so we are crossing planetary boundaries, such as biodiversity loss, freshwater withdrawal, and climate change. I created this visual model because I believe images help

us think differently. They show things we don’t notice at first. People’s reactions demonstrate this. I am surprised so many people are attracted to this model. Personally, I see the doughnut model as a compass for changing the economy. It helps us capture how we affect planetary boundaries as we realise our needs. This insight will keep us from focusing on growth. We have not applied a model like this before. That is why I set up the Doughnut Action Lab with colleagues, so that we could put the doughnut model into ­practice, for example in a community or classroom. We work a lot with cities, including ­Amsterdam. Amsterdam uses the doughnut model to become circular. This means that no waste matter is left over; all materials, such as textiles and plastic, are reused. This is an ambitious goal, but cities have to move in this direction. Our ecological ­footprint must be reduced. Amsterdam’s ambition is to be completely circular by 2050. By 2030, the city aims to achieve 50 per cent circularity. And by 2022, 10 per cent of the city’s purchases must be circular. This goal is not only good for the environment, but it also creates new initiatives. Amsterdam is already very ­focused on cyclists and accessible public transport, with its trams and metros, but new things are being added as well. One example is car sharing. Sometimes people think that replacing fossil fuels with


KATE RAWORTH is an economist at Oxford ­University and Professor of Practice at the Amsterdam ­University of Applied Sciences. In 2017, she published the book Doughnut Economics: Seven Ways to Think Like a 21st-­ century Economist.

electricity is enough, but that is not the solution. There is still a lack of space, and we still consume a lot of energy, because many people have their own car. We must move towards fewer possessions so there is space in the streets again for cycling, ­playing and creating connections between people, among other things. That is why car sharing is better. I do the same with my family now and it works out fine. In the doughnut model, these kinds of initiatives work both ways: they are better for our social needs and for our planet. So, if we want to shape the future, we have to change our old behaviours and believe that we can do it.’ Leiden2022 | New Scientist | 33

Corinne Hofman

Hanne Riekerk Ferry Breedveld

Five driving


Countless people are working extremely hard to realise the many activities surrounding ­Leiden as the European City of Science in 2022. Including these five. Text: Peter de Jong Photography: Bram Belloni

Ferry Breedveld (71), Professor of Internal Medicine, specialising in ­Rheumatology, leads the highlight of ­Leiden2022 together with Corinne ­Hofman: the EuroScience Open Forum (ESOF). With an expected 1500 physical participants and another 3500 online, this is the largest interdisciplinary conference 34 | New Scientist | Leiden2022

in Europe. ‘The ­subjects chosen can best be summarised as the greatest challenges of our time: ­migration, climate, energy transition, medicine development, identity and ­science for policy,’ says Breedveld ­enthusiastically. ‘I am hoping for a ­celebratory meeting between all kinds of ­scientists and the citizenry, centred around the magnificent Pieterskerk, ­connected by red carpets to the nearby auditoriums. I am looking forward to ­attending many great talks, meeting many people and visiting the cafés.’

Corinne Hofman (62) is a Professor of ­Archaeology and senior researcher at the Royal Netherlands Institute of Southeast Asian and Caribbean Studies. Together with Ferry Breedveld she is at the helm of ESOF. Hofman’s main goal is to build bridges between science and society. ‘Collaboration between the two is now more important than ever. Just think about climate change. Scientists and politicians can come up with all kinds of ideas, but the citizens will ultimately have to ensure that the world remains liveable. It is important that they feel involved in the problem. So let the field of science listen to society. The people themselves also have all sorts of ideas and solutions. When it comes to earthquakes, tap into the knowledge of the people in a ravaged country like Haiti. What materials do they use to make their homes earthquake-proof? They know the local situation

Chris Jaeger

Sahra Almahmood

best. Hopefully we can also bring together Western and non-Western knowledge at the conference, so that we can learn from each other. I would love that.’ Hanne Riekerk (25) is in luck. Last ­summer she completed her studies in ­biomedical sciences, one week later she ­already started working at Leiden2022 as a science communicator. Her favourite event is the European Union Contest for Young Scientists (EUCYS), a competition in which people between 14 and 24 from all over ­Europe are given a chance to share their research with the world. Riekerk: ‘We ­attended the previous edition of EUCYS in Salamanca, Spain. It features everything: technology to detect deepfakes, a study on the dying of stem cells and someone who had grown algae in PET bottles. What those young people showed us was impressive. The competition is given a new look in ­Leiden2022. We are making room for the ‘soft’ side of science, such as philosophy,

linguistics, and sociology. And the arts are also given prominence. Art stimulates ­curiosity and makes you look at reality in a ­different way. Maybe we will discover a new Rembrandt!’ Chris Jaeger (33) is project manager at Kennis door de Wijken (Knowledge through the Neighbourhoods). She has been speaking to an endless number of ­residents to see how they can participate throughout the year. A good example is the Tuinstad­Staalwijk neighbourhood. ‘This neighbourhood is keen to focus on architecture. Buildings range from Dudok (Dutch architect, 1884-1974 - ed.) to social housing. ­Together we walk past the various architectural styles where the knowledge of the city historian meets that of residents who have lived there since childhood.’ ­Kennis door de Wijken is something that has never been done before and of which Chris is very proud. ‘I was born in Oegstgeest and have lived in Leiden for twelve years. It is nice to meet other

‘It will be hard work, but we have a great team and I get a lot of energy from all the enthusiasm in the neighbourhoods’

proud residents and to create something together.’ Is she reluctant to go into the 101 neighbourhoods of Leiden and the surroun­ ding area for 365 days? ‘No, I am looking forward to it! It will be hard work, but we have a great team and I get a lot of energy from all the enthusiasm and initiatives in the neighbourhoods.’ Sahra Almahmood (29) is the indispensable oil in the wheels of the organisation of Leiden2022. As office manager, she ensures that everything runs smoothly in terms of secretarial and organisational work. During our conversation she is called no less than three times with urgent messages, but she doesn’t let herself get distracted. Almahmood, a communications management graduate, says: ‘I am looking forward to the different ways we are going to connect ­science, knowledge, arts and craftsmanship. Art features heavily in ArtScienceWeek, ­science in the Euro Science Open Forum, and so we fill the whole year. Personally, I am most looking forward to the outreach activities, in which we can entice people who do not usually encounter science to do so. We will see if we can really connect ­society with science. I am already looking forward to seeing what is going to happen at the Night of Discoveries.’ Leiden2022 | New Scientist | 35