Scientists and non-scientists co-creating breakthrough citizen science projects for measuring, understanding, and mitigating air pollution. That’s what happened during the first international workshop of the newly established Citizen Science Lab from 22 until 26 January at the Lorentz Center at Leiden…

On Friday morning, 8 June, Thijs Bosker, Associate Professor at Leiden University College, was interviewed by NPO Radio 1 on plastic pollution in Antartctica: ''Anually, an additional 4 - 12 billion kilos of plastic ends up in our ocean''.

From 26 to 29 September 2017 the International Conference on Microplastic Pollution in the Mediterranean Sea was held.

On 27 November 2019, the Royal Netherlands Academy of Arts and Sciences (Koninklijke Nederlandse Akademie van Wetenschappen) organized a symposium on the plastic pollution crisis.

Catalyst research aims to make gasoline less polluting. It turns out that during experiments it is actually necessary to protect catalysts from air itself. Publication in The Journal of Physical Chemistry C on August 26.

Promotores: Prof.dr. C.U. Keller, Prof.dr. H.C. Gerritsen

In astronomy, the interpration of observations and measurements plays a crucial role: we rely purely and fundamentally on the information that reaches us as observers. And 80% of all matter in the universe is undetectable directly.

Two years after the first conference, the Napels based Institute of Chemistry and Technology of Polymers, together with a consortium of organisations and research institutes, organised the second conference from 15 to 18 September in Capri, Italy.

In our globalised economy, goods and services are frequently produced abroad. Is it the producer or the consumer that should be held responsible for greenhouse gas emissions associated with production? Together with colleagues from Berlin, Hauke Ward of the Institute of Environmental Sciences (CML)…

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.

After many years of preparations, CERN has approved a groundbreaking new experiment: the Search for Hidden Particles (SHiP). Physicist Alexey Boyarsky was involved from the start. ‘We know there is physics that’s missing and we aim to find it.’

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…

More than three quarters of the 237 million Indonesian population has no access to tap water. They are dependent on water from rivers often polluted by industry. Laure d’Hondt conducted research into why it is so difficult to tackle these polluters and will defend her PhD dissertation on 17 October.

Leiden PhD student Xuequan Zhou has designed a new promising molecule that efficiently kills cancer cells, but does not harm healthy tissue. The trick: the drug is only active when irradiated with light. Zhou’s new compound does this extra efficiently by cleverly self-organising into nanoparticles.…

From 27 to 31 January, a workshop on the regulation of plastic pollution based on scientific evidence will be held at the Lorentz Center in Leiden.

This study seeks to identify suitable local environments conditions for the objects displayed at the Jordanian museums using the proper methods in order to contribute to the stabilization of these objects.

This thesis studied in depth the energy use and CO2 emissions of the industrial sector in China.

Has the industrial sector in China effectively been decarbonizing in recent years, across different regions and subsectors, and is it plausible that it will reduce its CO2 emissions in conformity with national and internationally pledged emission goals?

Fishes rely heavily on sound to find their way during migration or dispersal. Many species are affected by noise pollution. Hans Slabbekoorn from the Institute of Biology Leiden received a HORIZON2020 grant of 500,000 euros to study the impact of sound conditions on movement decisions of fishes.

Anthropogenic noise has been shown to affect marine animals in various ways, this may have fitness consequences at individual and population level. This thesis aims to increase insight into the quantification of sound-induced behavioural responses that are relevant to fitness, and into factors that…

This article traces the evolution of interpretations of international law and international cyber norms on responsible state behaviour in cyberspace by reassessing five major – and allegedly state-led – cyber operations: Stuxnet 2010; Belgacom 2013-2014, the Ukrainian power grid 2015, the US presidential…

Promotor: S.M. Verduyn Lunel, Co-promotor: O. van Gaans

Light makes us flourish – in this respect we humans are just like a rose or an azalea. Light can also be used to treat people who are ill. In Leiden, Sylvestre Bonnet and Esther Habers are working – each in their own discipline – on new applications of light in a clinical context.

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…

Chemotherapy that does nothing until you irradiate it with light. Sylvestre Bonnet receives a Vici grant of 1.5 million euros for the development of this treatment. The Leiden chemist wants to build a new molecule to fight tumours that are at the time still difficult to treat.

In 2013, Sylvestre Bonnet received an ERC Starting Grant to kill cancer with molecules that can be activated by light. Two postdocs and three PhD students later, the end approaches of his so far successful project.

Dark matter is one of the biggest mysteries of the Universe. Its properties cannot be explained with the known laws of physics and elementary particles.

Physicist Martin van Exter works with light at nanoscale, at the forefront of nanocomputer research. But as Director of Education he also has a vision for physics teaching. Inaugural lecture 18 November.

Depictions of Rembrandt, Michelangelo and many other artists are given a new dimension in an exhibition in the hall of the Oude UB at Leiden University. The exhibition - 'Multiple Images' - opens officially on 15 February. Artist Rudi Struik has given the slides of Leiden art historian Henri van de…

Farmers on the outskirts of Nairobi National Park protect their livestock using flashing lights on top of the animal enclosures. This system keeps lions away at night. Leiden research has shown that the method is both simple and effective. Publication in PLOS ONE.

Promotor: W.T. de Groot

Promotor: Carel J. ten Cate, Co-Promotor: Hans W. Slabbekoorn

The Old Observatory houses four historical telescopes. On this page you can learn more about them.

An international team led by Leiden astronomers has, after years of searching and defying the boundaries of a telescope, for the first time directly captured polarised light from an exoplanet. From this light they can deduct that a disk of dust and gas orbits the exoplanet. In this disk moons are possibly…

Physicists have manipulated light with large artificial atoms, so-called quantum dots. Before, this has only been done so well with actual atoms. It is an important step towards light-based quantum technology. Publication on August 30th in Nature Communications.

Bredero (1585-1618) was known for his farces and comedies, but he also wrote one tragedy. According to Olga van Marion and Tim Vergeer, the play's main protagonists Rodd’rick and Alphonsus were not competing for the love of a lady, but were in love with one another.

Many astronomers suspect that most of the matter in the universe is invisible. So how can you weigh dark matter if you can't actually see it? Professor Henk Hoekstra is looking for a solution. Inaugural lecture 25 June.

Leiden astronomers and ecologists are developing an instrument that lets people measure the quality of surface water with a smartphone.This international citizen science project, MONOCLE, is a collaboration between scientists and local people in Tanzania, Brazil and four European countries.

From simulations of galaxies to analyses of MRI scans: scientific research needs more and more computing power. Leiden University is planning to set up a completely new facility for high-performance computing. The green light was given officially on 20 June.

An international team of astronomers has found an unexpected link between dark matter and visible stars in stellar systems. This discovery may even cause us to reconsider our understanding of gravity. They published on their discovery in 'Nature' on 1 October.

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…

On 16 May the first International Day of Light was celebrated all around the globe. Initiated by UNESCO, organisations in 87 different countries set up a total of more than 600 events to embrace the vital role of light and related technologies in science. In the Old Observatory in Leiden visitors could…

On 16 May the first International Day of Light was celebrated all around the globe. Initiated by UNESCO, organisations in 87 different countries set up a total of more than 600 events to embrace the vital role of light and related technologies in science. In the Old Observatory in Leiden visitors could…

It appears to be a paradox: ultra-thin material that absorbs all the incident light. Nonetheless, it does exist. Two Leiden researchers report on their research in ‘Applied Physics Letters’. The article is among the Top 20 of the most downloaded articles of this reputable journal in May.

A new way to decipher the light from distant worlds could give us unmistakable evidence of extraterrestrial photosynthesis, and maybe alien plants, finds astronomy author Colin Stuart in the New Scientist. In his article, he describes the work of the group led by Leiden astronomer Rob van Holstein.…