KANI KARACA isn’t used to working in these conditions, but he gives it his best shot. The 75-year-old singer, one of Turkey’s best known, is accustomed to hearing his songs resonate around Istanbul’s grand mosques. But today he’s in a studio with sound-absorbing walls, and his voice sounds deadened and uninspiring. Karaca’s not about to throw a tantrum, though. His recording could be the key to preserving some of Turkey’s finest buildings. The singer is involved in a project to prevent the mosques of Mimar Sinan, the master builder of the Ottoman Empire, from losing their splendid acoustics.
Sinan lived from 1489 to 1588 and designed some of Ottoman Turkey’s grandest mosques, including the stunning Süleymaniye in Istanbul, or Constantinople as it was officially called back then. His mosques boast ornate facades and lavishly decorated interiors, but there’s more to them than just visual beauty. Sinan also took unprecedented care over the acoustics so that songs, prayers, preaching and recital—all central to the life of a mosque—would carry.
Unfortunately, restoration efforts over the years have taken their toll on these wonderful acoustics. Sound has never been a consideration in conservation, says Zehran Karabiber, an acoustics researcher at the Yildiz Technical University in Istanbul. Some efforts to preserve and restore Sinan’s mosques have inadvertently corrupted the acoustics.
Take the Süleymaniye mosque, for example. It’s Istanbul’s second largest mosque and was Sinan’s tribute to his sultan, Süleyman the Magnificent. Sinan used a Roman technique to enhance the mosque’s acoustics. He set jugs into the walls and domes, with their mouths open to the air. “The air circulation between the jugs and the room has an…
![Astronomers have long known that understanding how star clusters come to be is key to unlocking other secrets of galactic evolution. Stars form in clusters, created when clouds of gas collapse under gravity. As more and more stars are born in a collapsing cloud, strong stellar winds, harsh ultraviolet radiation and the supernova explosions of massive stars eventually disperse the cloud, and their light can bear down on other star-forming regions in the galaxy. This process is called stellar feedback, and it means that most of the gas in a galaxy never gets used for star formation. Researching how star clusters develop can answer questions about star formation at a galactic scale. Now, the state of the art has been further developed with both Hubble and Webb working together to provide a broad-spectrum view of thousands of young star clusters. An international team of astronomers has pored over images of four nearby galaxies from the FEAST observing programme (#1783), trying to solve this mystery. Their results show that it is the most massive star clusters that clear away their gaseous shroud the fastest, and begin lighting their galaxy the earliest. The team identified nearly 9000 star clusters in the four galaxies in different evolutionary stages: young clusters just starting to emerge from their natal clouds of gas, clusters that had partially dispersed the gas (both from Webb images), and fully unobstructed clusters visible in optical light (found in Hubble images). With Webb???s ability to peer inside the gas clouds, they were able to then estimate the mass and age of each cluster from its light spectrum. This image shows a section of one of the spiral arms of Messier 51 (M51), one of the four galaxies studied in this work, as seen by Webb???s Near-Infrared Camera (NIRCam). The thick clumps of star-forming gas are shown here in red and orange, representing infrared light emitted by ionised gas, dust grains, and complex molecules such as polycyclic aromatic hydrocarbons (PAHs). Within these gas complexes, each tens or hundreds of light years across, Webb reveals the dense, extremely bright clusters of massive stars that have just recently formed. The countless stars strewn across the arm of the galaxy, many of which would be invisible to our eyes behind layers of dust, are also laid bare in infrared light. [Image description: A large, long portion of one of the spiral arms in galaxy M51. Red-orange, clumpy filaments of gas and dust that stretch in a chain from left to right comprise the arm. Shining cyan bubbles light up parts of the gas clouds from within, and gaps expose bright star clusters in these bubbles as glowing white dots. The whole image is dotted with small stars. A faint blue glow around the arm colours the otherwise dark background.]](https://images.newscientist.com/wp-content/uploads/2026/05/13114322/SEI_296271016.jpg)