"The narrow scientists of his day accused him of insane."
Early science was not distinguished from philosophy - and the rejection of Aristarchus is one effect of that. People may have accused Aristarchus of being wrong, but none accused him of being an ignoramus. Aristarchus had good reasons for his opinions, but the scale of distances he was talking about were unbelievable to most people (infinity). Archimedes was one of those who disagreed with him - the same Archimedes who was one of the top 4 mathematicians of all time, and among the greatest scientists who ever lived. Hardly a "narrow" scientist. Nevertheless it's important to distinguish the scientists who disagreed from the philosophers and politicians who might have argued for some kind of suppression or punishment.

But even in that period, the world was known to be round - Eratosthenes was a contemporary of Archimedes and computed the circumference of the world.