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You know how it is. You watch your diet. You try to eat the right stuff, in the right amounts. You keep an eye on the latest news about diet and health. It’s tough enough at the best of times, yet for some reason the advice seems to keep on changing, so you end up not knowing whether you are doing the right thing or eating yourself into an early grave.
Take dietary fibre. You could be forgiven for thinking that eating lots of fibre is a good idea: according to almost every piece of official advice, it helps prevent colon cancer. Yet last year a large study published in The Journal of the American Medical Association concluded that you might as well not bother.
And it’s not just fibre. In the past few months the supposedly rock-solid benefits of eating a low-fat diet have been called into question by one of the biggest nutritional studies ever conducted. Another study debunked the benefits of oily fish. Add to that the endless flip-flopping over particular foods and nutrients – carbs, fats, eggs, nuts – and it’s no wonder we’re all finding it so hard to know what to eat.
Why is it so difficult to nail down what constitutes a healthy diet? Why, despite hundreds of studies over many decades, do we still not have a sure-fire recipe for good health? The answer, it turns out, is that when it comes to humans and food, getting rock-solid answers is like squeezing juice from a kumquat.
The idea…
![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)
