Burning Man at 40: the once anarchic desert festival faces a midlife crisis

The subversive bacchanal for San Francisco's eccentric underground is ageing out amid an influx of the super-rich

Burning Man, the infamous arts festival in the Nevada desert, turned 40 this year, and it's showing some distinct signs of middle age.

It's not just the tech billionaires who show up to party, the chartered flights straight to the desert or the HBO documentary about behind-the-scenes power struggles. The tens of thousands of people who assemble each year to create a tent city in the wilderness appear to be growing older, and it doesn't seem that they're being replaced by as many younger burners", as festival participants are called.