But people did had eyes to see how easily birds can ride the winds along the sky. And ships also existed from where birds flying in formations over the sea coul

But people did had eyes to see how easily birds can ride the winds along the sky. And ships also existed from where birds flying in formations over the sea could be seen. edit: But it seems people did know since 3000 years, not all were trapped in superstition and ignorance. https://en.m.wikipedia.org/wiki/Bird_migration https://en.m.wikipedia.org/wiki/Bird_migration