human being as well as nature can be described with
periods, that is why a man is exposed to the periodic
influences. Lunar cycles, winter-summer seasons and
day-night changing are considered to be external
influence's factors. On the other hand the
"biological clock" determines a person's life.
In the East the biorhythms had been known long before
3000 years ago. The famous Book Of Changes which
predicts the future and gives advice for any occasion
was written on its basis.
The first studies of biorhythms were made in Berlin in
the 19th century. Nowadays the biorhythmic theory can
explain the reasons of being in good or bad state
without the apparent cause; being tired when a person is
fit for nothing; feeling surge of strength to do one's
The theory makes it possible to know for sure when a
person can get the best of it in business, sport,
education and even in private life. Biorhythms are also
widely used to prevent accidents, to control the
person's state of health and to predict the possibility
of partners' compatibility.
Each of these biorhythms starts at the time of birth.
Cycle is divided into active phase (above zero level)
and passive one (below zero). The day of changing phase,
when one or more rhythms are changing from active to
passive phase and vice versa is a critical day. The
"critical day" means that the associated abilities are unstable,
and it is wise to be really careful during that day.