The future history of the Sun

Imagine you knew nothing of the human species. I hand you a photo of a child, say 8 years old. What can you say about that child’s future, biologically? 

Not much. You can maybe measure their height, look at their skin and hair color and shape, the lengths of fingers and arms and such… basically make physical measurements and observations but there’s not much of a conclusion you can draw about their future. You lack knowledge of their past and importantly their context; you’ve only seen this on...