The Cosmic Game ( PDFDrive.com )

Cosmic Game © Douglass A. White, 2012 v151207 53
that the first three devices involved an object sliding on a flat surface at an angle from an
arbitrary "horizontal" reference surface, and the second three involved a body rotating on
a pivot. The wedge is a movable inclined plane, and a screw is actually a combination
of the incline and the pivot of a lever. A gear is a specialized wheel with axle. The gear
teeth serve as a form of lever attached to a wheel to enhance the gripping power of the
wheel rim against another object. We shall first investigate the knowledge of inclined
planes that is encoded in the Senet Oracle Board.
The Inclined Plane
Earlier in our discussion I drew diagonal lines across the rectangular Senet Board. This
divided the rectangle into two wedges or inclined planes. If the slope is too steep, the
advantage of the ramp in assisting the lift is much reduced. It becomes like climbing a
sheer cliff as opposed to walking up a gentle hill. On the other hand, if the slope is too
gentle, then the length of the ramp becomes an issue. The Senet Board incline of 1:3 or
3:10 are smooth inclines. If one builds a staircase, the rise-to-tread ratio of around 17/29
≈ .59 is considered optimal, but ranges to 7/10.6, which gives a ratio of .66. If we take
the 3:10 Senet Board as a staircase with two steps, one in the domain of earth and one in
the domain of heaven, then we have a ratio of 3/5 = .6, which fits nicely in the optimal
range for an incline, ramp, or stair step. A rise of only 51 mm requires a tread of 523
mm to accomodate the swing of the climber's leg.
The Lever in the Senet Oracle Board
The lever was definitely a core device in Egyptian culture, because it was enshrined in
the sacred text that we usually call the Book of the Dead and appears as a standard
feature of Egyptian tomb art in the form of the Scale of Justice used to weigh the heart.
The layout of the Senet Oracle Board is based on this Weighing of the Heart Tableau, and
although we do not have surviving Oracle Boards that show this layout, its importance to
the Senet Board is heralded in the opening phrases of the Senet Game Text that invoke
the traditional sequence of nature deities that would appear on it. The word "lever"
means to lift and expresses the common use of the device.
The lever consists of four fundamental components: a resistor, an arm, a fulcrum, and a
tensor -- the latter being someone or something that pushes or pulls on the arm with
effort. The fulcrum is the pivot point of the lever and requires an external object on
which the lever arm rests with a small contact surface or an axle that passes through the
arm. The contact surface or axle must form an axis normal to the direction of the arm's
intended motion so that the motion is equatorial to the axis. Some levers are used to
move things, and other levers are intended to be static and hold a system in equilibrium.
The resistor is often a weight that is to be moved.
There are three possible classes of levers, that depend on the relative positions of the four
key components. There is no hierarchical order in the classification and in all cases the
mechanical advantage depends on the relative locations of the resistor, tensor, and