Exercise 4
Sense of Direction

Contents List:

Preparation
Procedure

Go to:

Exercises
"Campus"

Preparation

Select a time when you feel tranquil and have no pressing worldly concerns. Find a quiet spot, indoors or out, where you are unlikely to be disturbed.

Procedure

Think of the words that are commonly used in your language to denote a spatial direction, e.g.: front, back, before, behind, right, left, up, down, above, below, north, south, east, west, around, clockwise, anticlockwise.

Now suppose you are writing a description of a local scene in such a way that any reader with a good grasp of English could readily make a reasonably accurate mental picture of the scene you are describing. Which of the words listed in the preceding paragraph would you be most likely to use? Could any of them convey a clear meaning to a reader anywhere on Earth without a mutual understanding of one "datum" point and at least one specific direction or "axis" passing through that point? In other words, would you not first have to "set the scene" by writing something like "I am standing on a hill and looking towards the northwest"?

Carefully consider what factor or factors you may safely assume that you and your readers have in common that will enable them to "make sense" of the remainder of your description.

Now, as in Exercise 3, imagine yourself leaving the Earth, rising higher and higher through the Solar System, and eventually floating in inter-galactic space beyond the Milky Way. You decide to halt your progress at a point where there is no detectable gravitational attraction in any direction. From where you are, you can see countless galaxies glowing in the far distance and perceive that the Milky Way is just one of them.

Imagine you suddenly find yourself surrounded by six or seven little white balls each individually identifiable by one spot of a colour different from that on all the others. The balls are moving around you in orbits in different planes. By carefully observing their spots, you see that all the balls are rotating in different directions with respect to both their orbits and their axes of rotation, and that their several axes seem to be inclined at various angles with respect to each other.

How could you begin to give a clear description of the behaviour of each ball relative to all the others for the benefit of an Earth-bound reader? Would such a reader be able to translate your description so as to tell his neighbour how one of these little balls moved relative to the Earth?

The introduction of this Exercise need not inhibit the continued practice of Exercises 1, 2, and 3.