Hinton - The Fourth Dimension.pdf

74
THE FOURTH DIMENSION
constituents, would have to be described as two-dimensional.
But, however artificial the conception of a plane being
may be, it is not the less to be used in passing to the
conception of a greater dimensionality than ours, and
hence the validity of the first part of the objection
altogether disappears directly we find evidence for such a
state of being.
The second part of the objection has more weight.
How is it possible to conceive that in a four-dimensional
space and creatures should be confined to a threedimensional
existence?
In reply I would say that we know as a matter of fact
that life is essentially a phenomenon of surface. The
amplitude of the movements which we can make is much
greater along the surface of the earth than it is up
or down.
Now we have but to conceive the extent of a solid
surface increased, while the motions possible transverse
to it are diminished in the same proportion, to obtain the
image of a three-dimensional world in four-dimensional
space.
And as our habitat is the meeting of air and earth on
the world, so we must think of the meeting place of two
as affording the condition for our universe. The meeting
of what two? What can that vastness be in the higher
space which stretches in such a perfect level that our
astronomical observations fail to detect the slightest
curvature?
The perfection of the level suggests a liquid—a lake
amidst what vast scenery!—whereon the matter of the
universe floats speck-like.
But this aspect of the problem is like what are called
in mathematics boundary conditions.
We can trace out all the consequences of four-dimensional
movements down to their last detail. Then, knowing