How do you imagine heaven? Perhaps the traditional image is that of sitting on clouds, Yahweh or Allah or Zeus always being around the corner not having to explain the problem of evil, where you meet all your friends in life as well as those people you admired but never met—and generally a world in which everyone is as happy as they can be. People and religions vary in their conceptions of what this utopia is like. Some Hindus, for instance, believe that heaven is a place where you have none of your earthly desires. Muslims, on the other hand, see heaven as a place in which all your earthly desires are sated. But what is a perfect world, and is such a thing possible in principle, even if not in practice? [Read more →]