Definition of Second

It is equal to the duration of 9,192,631,770 periods of radiation of Cesium-133 in ground state.

The perception of the world is changing Our thinking is shaped by several factors: education, personal experience, public opinion on certain issues. Books also have a powerful effect on him. This is especially true of literature on self-development, psychology, self-study. Books develop our thinking. They help to look at the world from the other side, to reconsider priorities, values, to set new goals.