Visual space, unlike the spaces which relate to or emanate from touch and taste and hearing has a stable and enduring character. When a plane lives the ground it quickly diminishes in size and the little boy was justified in asking his question. Perhaps the answer is in the fact that the enclosed space of the cabin is visual and static. In fact, visual space is a figure without a ground , having abstracted itself from the ground of the other senses. Acoustic space, for example has quite different properties from visual space.
Acoustic sphere is discontinuous and non uniform and dynamic.
In the classic study of play in Homo Ludens , J. Huizinga reveals the indispensable quality of a mobile relation between figure and ground which creates patterns of deep involvement and participation for the user. On a visit to Nassau, I asked Al Sheppard whether there was any upside-down in outer space. This seems to have some bearing on other matters, since for most small children there is no upside-down in a picture book. This relationship is discovered later by our children, but seems not to be part of the Eskimo experience. In the same way, the cave painters did much of their work completely out of sight, under rock ledges.