> There's actually a third intractable reality up against star travel: How is this intractable? This is a moral argument. It won't stop anyone from doing it. I

> There's actually a third intractable reality up against star travel: How is this intractable? This is a moral argument. It won't stop anyone from doing it. I am not sure you are using the word intractable correctly. It implies impossible, or unrealistic to be solved even if hypothetically possible, etc. Whereas from what you say it seems it's possible, you just think it should not be done (due to being in your view immoral). Very different things.