Robin Hanson and Katja Grace pose an interesting question:
Consider two possible civilizations, stretched either across time or space:
•Time: A mere hundred thousand people live sustainably for a billion generations before finally going extinct.
•Space: A trillion people spread across a thousand planets live for only a hundred generations, then go extinctEven though both civilizations support the same total number of lives, most observers probably find the time-stretched civilization more admirable and morally worthy. It is “sustainable,” and in “harmony” with its environment. The space-stretched civilization, in contrast, seems “aggressively” expanding and risks being an obese “repugnant conclusion” scenario. Why?
The Dish 