Life Extension

Because of the time-dilating effects of Interstellar travel, there can be significant differences between the number of years someone has experienced in the course of their life, and their “real” age. “Subjective age” describes someone’s perceived age – in terms of how old they look to observers, and how many years they have experienced – and “real age” describes their age in Union Standard Years (abbreviated as “u”). Union’s standardized system measures the passage of time as it is perceived on Cradle. Therefore, a Cosmopolitan’s real age might be much higher than their subjective age, depending on how much time has passed on Cradle while they travel between the stars. This phenomenon is called “relativistic life-extension” (and is a reliable method of ”time travel” in Lancer, though it only goes forward).
Without augmentations or significant bioengineering, the average Diasporan from a developed world has a lifespan somewhere between 120 and 150 subjective years. The average Cosmopolitan tends to live between 170 and 200 subjective years. Meanwhile, most Metropolitans live between 180 and 220 subjective years. With access to the most advanced medicine, augmentations, and other technologies, humans can live to a maximum subjective age of around 300 years. Real ages can vary considerably from these numbers, even for people who don’t travel, as the particular interactions of worlds and stars can lead to slippery interpretations of time. It’s perfectly possible for someone to be 300 years old according to Union’s records even though they’re only 30 years old in subjective time.
By contrast, the relativistic life-extension that takes place as a result of interstellar travel has no real limit, but neither does it change the subjective experience of time. The span of life itself remains limited by physiology and the technologies that support it.