Question about the middle of the earth's surface .?

i just wonder about those who live in the center of the world ( on the surface of the earth ) if you know what i mean .. for example those who lives on the greenwich or greenitch line , in the middle of earth . because they must see the night and morning since they live on the virtual line that separates between night and morning , so does they really see night and morning together or wut ? any idea about this thingy .. ?