SpaceWhat is a galaxy? That's a surprisingly difficult question to answer Figuring out what really counts as a galaxy could give us insights into dark matter and potentially shake up astrophysics, cosmology and particle physics, says columnist Chanda Prescod-WeinsteinComment
HealthUltra-processed foods could be making you age faster We’ve been missing an important contributor to ageing, says columnist Graham Lawton. Ultra-processed foods are known to be associated with many chronic health problems, but studies have now shown they may also speed up ageing Comment