3 ms·
> Initial estimates put the sun’s lifespan at around 20 million years. It could hardly be much younger than that, so its lifetime appeared to be mostly over. So
by gwern 3y ago
> Initial estimates put the sun’s lifespan at around 20 million years. It could hardly be much younger than that, so its lifetime appeared to be mostly over. Soon it would burn out. What about the earth? It would freeze over, its orbit would decay, and it would draw closer to the husk of the sun, becoming tidally locked. Ultimately, it would fall into the remains of the sun and be destroyed, but not until long after all life went extinct.
- Vecr 3y agoYeah, that's in the article. I should look at the emissions curve for various stages of red giant stars. Maybe it's a late phase red giant, and the planet was always far away? It would need increased emissions and then they would have to start going down again. It is kind of suspicious for life to start on a planet only after the star starts expanding into a red giant, but it might be a similar handwave to the characters being human like.