On a globe hanging in empty space, where is "up"? The Sūrya-Siddhānta (~5th century CE) answers: nowhere. Everywhere on Earth, it says, people "think their own place to be uppermost" — and observers on opposite sides of the planet each suppose the other underneath. Aristotle's Greece had the spherical Earth by ~350 BCE; a millennium after this Sanskrit verse, European scholars were still debating whether the antipodes could be inhabited. The Siddhānta treats it as geometry, not controversy.