Tennis Courts for Two-, Three-, Four-Dimensional Games. - N.d. - Drawing : lead pencil and pen : 20 x 26 cm
At the foot of the drawing, a text reads as follows:
In this 2-D game, the court is 1-dimensional, and the net and players stand at right-angles to it in a second dimension.
The ball is flying thru two-dimensional space; only when it bounces does it touch the line of the court. The players are flat and the ball is disc-like.
In this 3-D game, with which we are familiar, the court is 2-dimensional, and the net and the players stand (at right-angles to it) in a third dimension.
The ball is always flying thru three-dimensional space; only when it bounces does it touch the two-dimensional surface of the court, or when it rolls on the ground.
FOUR-DIMENSIONAL GAMES (perspective views)
In this 4-D game, the court is three dimensional, the net and the players stand out (at right-angles to it) in a fourth dimension.
The ball is always flying thru four-dimensional space; only when it bounces does it touch the three-dimensional space of the court, or when it 'rolls around' in the volume or "ground" of the court.
The players feet are usually touching the volume of the court. Only if they fall do others parts of their body come in contact.
The players have to be 4-dimensional and the ball a hyper-sphere!