How a 500-year experiment to revive dormant microbes could reveal the secrets to cheating time ... For almost as long as we have known about micro-organisms, we have known about dormancy. In 1702, the Dutch biologist Antonie van Leeuwenhoek collected some dried ‘animalcules’ from a nearby gutter and added water. Peering through his handmade microscope, he observed that ‘they began to extend their bodies and in half an hour at least 100 of them were swimming about the glass’. ... Aged 70, van Leeuwenhoek had just discovered the dormant states of rotifers – small, wheel-shaped animals that can be found in many transient freshwater habitats. When conditions become too Spartan, these humble organisms contract into dry, oval-shaped husks in order to survive. ... Water is essential for life, and yet anhydrobiotes appear to get by without it. How? According to the ‘water replacement hypothesis’, they exchange their cellular fluid for sugars such as sucrose and trehalose. The result is a glass-like substance that not only retains the cell’s shape on rehydration, but also slows down a lot of unwanted chemical reactions. With this scaffolding in place, they reduce the fires of their metabolisms to embers, conserving their energy like a ground squirrel within its winter den, waiting for conditions to improve. They keep things ticking over.