The concept of "up" and "down" is subjective and relative to the observer's perspective. The choice of which direction is considered "up" and which is considered "down" is primarily based on cultural and historical factors, rather than any inherent property of the Earth or the universe.
The convention of using north as up and south as down on maps and globes can be traced back to ancient civilizations and the development of cartography. Early mapmakers, such as the ancient Greeks, chose to align maps with north at the top due to various historical and practical reasons. The concept of cardinal directions, including north, south, east, and west, emerged from celestial navigation, where the North Star (Polaris) served as a reference point for determining direction.
The choice of north as up is also influenced by the fact that the Earth has a magnetic field, and the magnetic north pole is near the geographic North Pole. This connection between magnetic north and geographic north might have reinforced the perception of north as "up" over time.
It's important to note that this convention is not universally followed. In some cultures or regions, maps are oriented with east or another direction at the top. For example, ancient Egyptian maps were often oriented with east at the top to align with the direction of the rising sun.
Ultimately, the choice of which direction is considered "up" is arbitrary and based on convention and human cultural practices. There is no inherent reason why any particular direction should be considered "up" or "down" in an absolute sense.