rotation

Photographs and simple text describe some of the changes that occur with the seasons, and explain why seasons happen.

Explains the difference between day and night, why days are longer in the summer, and what animals only come out at night. Activities show readers what the sun, earth, and moon do and how this makes days, months and years.

Explains why the Earth experiences day and night; looks at the sun's path across the sky, shadows, and the sky at night; and provides information about other related topics such as time zones, moon phases, and eclipses.

Explores the life and work of nineteenth-century French physicist L?on Foucault, who invented a pendulum that provided proof that the Earth rotated on its axis.

Explains why day turns into night, how the moon changes shape, and why we have different seasons and time zones.

Simple text and photographs explain a year as a unit of time and Earth's orbit of the sun.

Simple text and photos explain a month as a unit of time and the months in a year.

Provides answers to thirteen questions about time, tides, and revolutions, discussing the Earth's orbit, seasons, the length of a year, clocks, the International Date Line, and more.

An examination of the phenomena and scientific principles behind the changing of the seasons.

Photographs, diagrams, and illustrations describe the Earth's natural cycles, how the cycles all connect with each other, and their importance to the environment.