Fish populations in lakes and rivers have declined in recent decades. This is probably due to light and noise pollution. The Horizon Europe grant enables ecologist Hans Slabbekoorn to investigate this and improve the situation for migrating fish. In order to do so, a seven-metre-long swimming tunnel…

The University believes it is important to provide you with a satisfying work environment. How do you feel about your career opportunities, the interaction with your colleagues and supervisors, and the work facilities at your disposal? We ask for your opinion via the personnel monitor. This survey guarantees…

After months of preparation, the moment of truth had arrived: would the skies above Leiden clear for the promised glitzy planet-and-star show? The people of Leiden turned out in their hundreds to go star-hunting on 25 September. They became more aware than ever of the effects of light pollution.

‘What if we switch off all the lights one evening? That idea crossed my mind from time to time. And when I mentioned it to a taxi driver one day, he said: “Oh, you mean: lights out, stars on!” That’s not completely true, of course, because the stars are always on, but his phrase summed up the idea n…

Did you know that algorithms can help with the prevention of air pollution and ships sinking in the sea? A team of Leiden University researchers have worked together with the Dutch Ministry of Infrastructure and Water Management to look in data-driven inspection of ships. In this interview, Gerrit Jan…

Rich countries are getting richer because of environmentally polluting (construction) investments from the past, largely at the expense of poor countries. This was shown by long-term economic and environmental data. 'The gap between poor and rich countries is widening.' Scientists from the Leiden Institute…

On 25 September, lights throughout Leiden will be turned off for the Seeing Stars event. What makes the urban night so special? We asked university lecturer Sara Brandellero, who researches cities, night and migration.

Cotton is the most widely used natural fibre for clothes. But how polluting are our jeans and shirts actually? Environmental scientist Laura Scherer coordinated an international research project on the impacts of cotton. ‘The purchases of consumers in Europe can contribute to water scarcity in China…

What will happen if the lights in a large part of the city are switched off? How many stars can you see without all that light pollution? This is what researchers, artists and the residents of Leiden are going to investigate during Seeing Stars Leiden on 25 September. ‘Leiden is the ideal place for…

Canal Watch (De Grachtwacht), which has been cleaning canals since 2018, has received the Dutch Research Council (NWO) Communication Initiative Award.

Rather than one key and one strong lock, biology often uses tens or hundreds of weaker links to bind parts together, such as cells membranes. This allows for selectivity and also reversibility: the binding can also be undone. Researchers first caught this phenomenon using spheres or colloids, and published…

Human resources

Nausea, neurologic pain and hair loss: some of the severe side effects of chemotherapy. Not necessary, biochemist Liyan Zhang showed. Together with Leiden biologists and others, she achieved great results with a drug that is only active in combination with light. Zhang will defend her PhD on 4 July.

Petr Steindl works on quantum dots in microcavities for his PhD research. He manipulates single-photons to create complex structures of light. Applications could include quantum communication and gates for quantum computers.

How wonderful would it be to use art, technology and science in Ukraine's recovery? Young Ukrainians currently residing in Poland get guidance to develop creative programmes and activities that can later be implemented. Leiden astronomers Pedro Russo and Kateryna Frantseva cooperate in the project.

Research to experiment with bacteria that grow like plants has been granted the NWO XS grant. These bacteria use light and carbon dioxide to grow, and will be designed especially for use in the biotechnological field. Tijn Delzenne and his supervisor Dennis Claessen can spend 50.000 euros on the exp…

New archaeological research into grave goods and skeletal material from the oldest grave field in the Netherlands shows that male-female roles 7,000 words ago were less traditional than was thought. The research was conducted by a multidisciplinary team of researchers led by Archol, the National Museum…

From 3 to 13 December you can see the exhibition Plastic Justice at the Kamerlingh Onnes Building. Esther Kentin, coördinator of the Leiden Advocacy Project on Plastic, saw the exhibition at the Plastic Health Summit and initiated a collaboration with the Royal Academy of Art in The Hague.

Writing with Light Magazine. Issue no.1 is now available for download as a open access pdf/interactive edition or purchase as limited-run print edition. The magazine builds on our prior work with the journals Cultural Anthropology and Visual Anthropology Review and the editorial collective consists…

For the first time, an international group of astronomers have seen the heat glow of two ice giant planets colliding. They could also observe the resultant dust cloud move in front of the parent star several years later. Led by Leiden astronomer Matthew Kenworthy, they monitored the star's brightness…

Archaeologist Bjørn Peare Barthold suspected farmers in a doctorless 19th century Dutch village may have been self-medicating to manage pain and disease. By examining the skeletons' dental calculus this hypothesis could be tested. Science Magazine interviewed him about this new technique.

Auke-Florian Hiemstra is the Leidsch Dagblad Person of the Year 2022.

'Education has always been something I am very interested in,' says the passionate Michiel Hogerheijde. He was already chairman of the astronomy programme committee and has been teaching for many years. Since 1 October, he is also the new Programme Director of the astronomy bachelor. 'I really enjoy…

We all know smoking is bad for our health. But we might not have known that the cigarette filters that litter our streets also impact the environment. Esther Kentin is a lecturer at Leiden Law School. She is raising awareness of the University’s cigarette butt problem.

The university is launching a campaign to focus extra attention on our smoke-free university locations. The University is using aptly named cigarette barrels to try to show clearly just how many cigarette filters are being saved from the environment. How harmful are these cigarette filters to the e…

December 2020 saw the crowning publication of the Landscapes of Survival project by Professor Peter Akkermans. Its main topic is human habitation in marginal environments like the deserts of the Arabian Peninsula. ‘The people living here built their own society, and they would not have viewed it as…

On paper it is recycled, but in reality enormous quantities of plastic waste from the Netherlands end up in Asian seas. Researchers from the Leiden Institute of Environmental Sciences charted the fate of plastic food packaging waste from the Netherlands. They published their results on July 8 in the…

Cosmologists can measure with increasing precision how the universe is expanding and changing. This is producing unexpected results and causing cracks in our picture of the universe. At the ESOF session The Dark Side of our Mysterious Universe, cosmologists, astronomers and philosophers will discuss…

Over the past few months, Urban Studies students have been helping to think about the realisation of the Humanities Campus. To test their knowledge in practice, the future urban specialists gave advice on several different aspects, including thermal energy storage and the new central campus building…

Leiden physicists Alexandre Morin and Samadarshi Maity study self-organisation and flocking phenomena. They shed light on flocking, which helps to understand how it is possible that birds in a flock don't collide. With plastic microbeads, they create an experimental setup and they developed a mathematical…

Leiden academics Remco Breuker and Auke-Florian Hiemstra stand to win the title of Person of the Year.

Veel mensen denken dat zware metalen giftig zijn en mens en natuur altijd schade aanbrengen. Dat beeld moet genuanceerd worden, vindt hoogleraar Sylvestre Bonnet.

Lecture, This Week's Discoveries

A group of biology students are working on a solution to the world’s plastics problem by getting bacteria to make biodegradable plastic.

Piercing through the skull with an ice pick, administering electric shocks without an anaesthetic, or applying leeches to the uterus: these may seem like medieval methods of torture, but they are in fact therapies used in medicine. Willem van der Does writes about all of them in his new book. ‘Physicians…

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