Stefoff, Rebecca

Examines the history of alchemy and how it split into two branches--alchemy and chemistry.

Looks at how scientists developed the size and shape of planet Earth.

Looks at the history of chemistry and how knowledge of the physical world has changed from the four elements of the ancient world to the development of the periodic table.

Examines astrology and astronomy and how they became two different ways to study the stars during the seventeenth century.

Discusses the travels of Vasco da Gama and other Portugese explorers who helped establish an extensive empire for their country.

Reflects on the puzzle of human revolution, on where we came from and where we may be heading.

Explains how coal power works, discusses its economics, and presents opposing sides on several issues concerning its use.

Describes the debate between the geocentric and heliocentric models of the solar system, with a discussion of the scientific method, which relies on observable phenomena and technologies such as the telescope.