Nitpick: It wouldn’t have to be commercial use of nuclear energy. Even if we’re limited to human institutions, it could be governmental use, and I have a notion that religion might be the best sort of institution for getting people off the planet. Religions have a potential for big, long term projects that don’t make practical sense.
Thanks for looking into the question of planetary mass and getting off the planet—once the question occurred to me, it exploded into a lot of additional questions, and we haven’t even gotten to whether planetary mass might have an effect on the evolution of life.
One additional factor: the amount of radioactive elements still usable (that is, not completely decayed) vs. how many billion years it took to evolve from alien amoeba to alien tool-users.
Nitpick: It wouldn’t have to be commercial use of nuclear energy. Even if we’re limited to human institutions, it could be governmental use, and I have a notion that religion might be the best sort of institution for getting people off the planet. Religions have a potential for big, long term projects that don’t make practical sense.
Thanks for looking into the question of planetary mass and getting off the planet—once the question occurred to me, it exploded into a lot of additional questions, and we haven’t even gotten to whether planetary mass might have an effect on the evolution of life.
One additional factor: the amount of radioactive elements still usable (that is, not completely decayed) vs. how many billion years it took to evolve from alien amoeba to alien tool-users.