On the Structure of Underground World in Verne's Journey to the Center of the Earth

Suppose your room is in the center of the earth, and the space is much larger, almost circular. The four walls of the ceiling floor are the crust inside the center of the earth, and the light bulb in the middle is the center of the earth. So whether you stand on the floor or on the western wall, the eastern wall, the northern wall, the southern wall or the ceiling, you can see the bulb-shaped core and the poor roof behind you at the same time. This is similar to the galaxy behind the sun that we can see on earth. If there is a shell behind the sun, we should be able to see it. After all, the inner diameter of the center of the earth is not as wide as the universe.