There are many technical and popular accounts, both in Russian and in
other languages, of the non-Euclidean geometry of Lobachevsky and
Bolyai, a few of which are listed in the Bibliography. This geometry,
also called hyperbolic geometry, is part of the required subject matter
of many mathematics departments in universities and teachers' colleges-a
reflec- tion of the view that familiarity with the elements of
hyperbolic geometry is a useful part of the background of future high
school teachers. Much attention is paid to hyperbolic geometry by school
mathematics clubs. Some mathematicians and educators concerned with
reform of the high school curriculum believe that the required part of
the curriculum should include elements of hyperbolic geometry, and that
the optional part of the curriculum should include a topic related to
hyperbolic geometry. I The broad interest in hyperbolic geometry is not
surprising. This interest has little to do with mathematical and
scientific applications of hyperbolic geometry, since the applications
(for instance, in the theory of automorphic functions) are rather
specialized, and are likely to be encountered by very few of the many
students who conscientiously study (and then present to examiners) the
definition of parallels in hyperbolic geometry and the special features
of configurations of lines in the hyperbolic plane. The principal reason
for the interest in hyperbolic geometry is the important fact of
"non-uniqueness" of geometry; of the existence of many geometric
systems.