From the deck of a ship or the window of a plane, it feels obvious that “down” points toward Earth and “up” points toward the ...

How Gravity Shapes Our Sense Of “Down” On Earth, gravity is the invisible force that shapes our understanding of space and direction. To us, “down” simply means toward the planet’s center. No matter ...

In the bigger picture, “down” could be defined as being below the plane of the solar system, which is known as the ecliptic. By convention, we say that above the plane is where the planets are seen to ...