‘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…

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…

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.

A suitcase covered with stickers from various universities, containing a quantum light source. Since April 2024, this suitcase has been visiting scientists in Europe researching single photons: the smallest possible quantity of light. The suitcase, also called ‘Q-torch’, travels from lab to lab like…

Hoping to learn something about the human brain, Leiden researchers are creating a setup to shoot single photons, particles of light, into someone’s eye. ‘The eye is a passageway to the brain.’

Packages of DNA strands containing silver, measuring just two or three nanometres in size. Leiden physicists Donny de Bruin and Dirk Bouwmeester create these packages, which can enter living cells on their own. They then activate the silver with light, causing the cells to break down. This could, in…

Ecologist Sebastiaan Grosscurt became a successful wildlife journalist after graduating. But he decided to focus on science instead. He started his PhD research this year on the cumulative effect of light and noise pollution on animal behaviour.

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…

'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…

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.’

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…

PhD student and research journalist Sebastiaan Grosscurt won a Tegel in May. In the data category, Grosscurt and his colleagues won the prestigious Dutch journalism award. 'For me, ecological research and journalism are two ways of achieving the same thing.'

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Since 24 March, the Kamerlingh Onnes Building of the Faculty of Law has been full of hundreds of colourful jellyfish. When the light falls in through the skylight, passing students imagine themselves in a magical underwater landscape for a moment. But behind that enchanting sight is a serious message:…

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…

While investigating 16 years of images of young stars from a retired astronomical camera, Leiden master's student Sam de Regt discovered that two of those stars were still enveloped in birth clouds. Never before has anyone captured these two stars in so much detail. He publishes his data-cleaning method…

A suitcase as a messenger of quantum science. That is the idea behind QuanTour, a project connecting researchers from 12 European universities. In December, the suitcase landed in Leiden. A month later, it is time to pass the baton to Copenhagen. But what happened to it in Leiden?

James Webb life’s building blocks

Smart drug carriers, uneven cosmic expansion, and solar energy storage in molecules. These are the topics of three newly awarded NWO-XS grants to researchers at the Faculty of Science.

Leiden artist Jos Agasi gets to create the artwork for the atrium of the new Gorlaeus Building. His work was chosen from several entries and will be a real eye-catcher in the building. The artist has a fascination for light and uses it to create works of art with all kinds of materials, objects and…

Researchers using NASA’s James Webb Space Telescope may have detected atmospheric gases surrounding 55 Cancri e, a hot rocky exoplanet 41 light-years from Earth. This is the best evidence to date for the existence of any rocky planet atmosphere outside our solar system.

For over a year now, the James Webb Telescope has been sending stunning images that exceed astronomers’ expectations. The photos are fascinating to see, but what exactly are we looking at? Assistant professor Melissa McClure explains.

The two instruments of ESA's space telescope Euclid have taken their first test images. The first images indicate that the space telescope will achieve the scientific goals for which it was designed - and possibly much more. Euclid will create a 3D map of a third of the sky, allowing scientists to study…

Minuscule elementary particles from space colliding with Earth can give us an insight into the distant objects they come from. But first, you need to know how to catch them. With a Vidi grant from NWO, researcher Sjoert van Velzen will 'hunt' for neutrinos coming from exploding black holes.

Astronomers have used data from the European Gaia Space Telescope to discover 55 high-speed stars launched from the young star cluster R136 in the Large Magellanic Cloud, a satellite galaxy of the Milky Way. This increases tenfold the number of known “runaway stars” in this region. The team of astronomers,…

An international team of astronomers led by Ardjan Sturm of the Observatory has made the first two-dimensional inventory of ice in a planet-forming disk of dust and gas surrounding a young star. The researches, including Melissa McClure, used the James Webb Space Telescope and publish their findings…

From the birth of the universe to the molecules in a planet's atmosphere. The first five pictures from the James Webb Space Telescope (JWST) show the enormous range in which the space telescope can operate. Ewine van Dishoeck, professor of molecular astrophysics, took a look at the first images Tuesday…

A group of astronomers led by Leiden PhD student Sebastian Zieba has discovered using the James Webb Space Telescope (JWST) that the rocky exoplanet TRAPPIST-1 c has a thin atmosphere. Although the planet is nearly identical to Venus in size and temperature, and was expected to have a thick atmosphere,…

Are magnetic fields older than the first light? And how did they influence the development of our universe right after the Big Bang? Cosmologists from Leiden, Groningen, and Utrecht are now collaborating to investigate this.

Space telescope Euclid is capable of unravelling the secrets of the universe. That is what the images published by ESA today show, according to astronomers working with the telescope's data. The images exceed all expectations. Scientists within the Euclid consortium, including astronomers Henk Hoekstra…

The first full-colour images of the cosmos from ESA's space telescope Euclid were presented today. Never before has a telescope been able to take such crystal-clear astronomical images of such a large part of the sky and so far into the deep universe. The five images illustrate Euclid's full potential;…

The 'deepest and sharpest' image of the Universe to date: the first photos from the new James Webb space telescope yesterday mesmerised astronomers and the public alike. Leiden Professor of Molecular Astrophysics, Ewine van Dishoeck, spoke to various media outlets about the first images, which include…

Students for Palestine – a group of students from Leiden and The Hague – are holding a panel discussion in the Leiden University in The Hague Wijnhaven building on Tuesday 24 May entitled ‘Silencing Palestine’.

How do galaxies form? That is what astronomer Mariska Kriek will be researching in the coming years. She received an NWO Vici grant of 1.5 million euros to study galaxies in the early universe. ‘This research uses new and unprecedented observations from the James Webb Space Telescope (JWST). These allow…

An international team of astronomers has discovered a large reservoir of hot gas in the cluster-in-formation around the Spiderweb Galaxy. Based partly on that hot gas, the astronomers predict that the cluster-in-formation will grow into one of the largest objects in the universe. A step closer to discovering…

For the first time, we’re seeing what Euclid sees. The telescope’s initial observations have provided a wealth of new information about our universe. But according to cosmologist Alessandra Silvestri, this is just the beginning. The research helps us gain a deeper understanding of the past, present,…

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