Eight people sealed themselves in a glass dome to prove humanity could feed itself on plants, and spent two years starving in front of the world's press. Biosphere 2 cost a hundred and fifty million dollars. Three acres of Arizona desert under sealed glass, eight crew, door shut on 26 September 1991, nothing in or out for two years. The farm inside was worked intensively and by any agronomic measure it was superb, out-producing the most efficient smallholder farming on earth by a wide margin. It produced 83 per cent of what they needed. Which left Roy Walford, the crew doctor, in a sealed box with seven hungry colleagues and his own life's work. Walford was a UCLA pathologist who had spent thirty years arguing that severe calorie restriction extends lifespan. He had doubled it in mice. And here was reality handing him his own hypothesis with the door welded shut. So he called it a health programme. The menu became vegetables, half a glass of goat's milk a day, and meat or fish about once a week. The men lost close to a fifth of their body weight, the women about a tenth. And the markers Walford cared about behaved impeccably: blood pressure, glucose, cholesterol and triglycerides all down at least twenty per cent, into ranges any doctor would frame. He published it in PNAS in 1992. The bloodwork was magnificent. The people were falling apart. Jane Poynter wrote the book afterwards. Fatigue, depression, mental fog, and a preoccupation with food that ate the entire interior life of the crew. They stole from each other. They split into two factions that stopped speaking. The ecological research the building had been constructed for was largely abandoned by people who no longer had the headroom for anything past the next meal. The ants and cockroaches, by contrast, were thriving. The air was leaving too. Oxygen started at 20.9 per cent and kept dropping and nobody knew where it was going. Columbia eventually worked it out: the concrete was quietly eating it. So oxygen had to be pumped in from outside, which is an interesting result for a sealed world. Walford's verdict on the mutiny is the whole thing in one sentence. He said afterwards that any other physician aboard would have panicked and declared they were starving, but that he knew they were on a programme of health enhancement. He knew. Seven other people, visibly wasting, were simply mistaken. He came out in 1993, developed ALS, blamed the conditions inside, and died in 2004 aged 79 after years on 1,600 calories a day in pursuit of a longer life. The mice got double. He did not make it to average for an American professor. Every argument you have heard this decade was already in that building. Grow it locally. Take the animals out. Eat less. Watch the numbers improve. Eight of the most motivated humans alive, handed three acres of the best-managed farmland on the planet and no meat, could not feed themselves. The press reported the fighting as a personality clash.