Scott Alexander examines the concept of 'light water' and its potential health benefits, critically analyzing various arguments while expressing fascination with this unexpected area of scientific inquiry. Longer summary

Scott Alexander explores the concept of 'light water' (water depleted of deuterium) as a potential health treatment. He begins with a hypothetical scenario about poisoning Castro with heavy water, then explains the science behind isotopes of water. The post discusses various arguments for light water's health benefits, including evolutionary, molecular biology, and oncological perspectives. Scott critically examines these claims, pointing out flaws in some arguments while acknowledging that some cancer studies seem intriguing. He concludes by expressing fascination with the unexpected dimensions along which scientific inquiry can progress, even if the medical benefits of light water remain unproven. Shorter summary