Recent studies suggest that the brain clears metabolic waste far more efficiently during deep sleep than while awake. As neurons rest, the fluid-filled spaces between them widen, allowing cerebrospinal fluid to flush out proteins linked to neurodegenerative disease. Researchers argue this nightly cleanup may explain why chronic sleep loss is so strongly associated with cognitive decline.

For decades, city planners prioritised cars, widening roads and demolishing older neighbourhoods to make room for traffic. A growing movement now reverses that logic, reclaiming street space for pedestrians, cyclists and public transport. Advocates point to quieter, cleaner districts and stronger local economies, while critics warn that poorly managed changes can simply push congestion elsewhere.