Revolutions in science

Presents an introduction to English scientist James Lovelock and his Gaia hypothesis, explaining how and why he came to the conclusion that Earth is alive, discussing how his theory was initially received, and looking at how scientists are using the Gaia theory to guide inquiries into how Earth works.

Investigates the reasons why sixteenth-century astronomer Nicolaus Copernicus was led to believe that the Earth was not the center of the universe but circled around the sun, and discusses the far-reaching consequences of his discovery for society and science.

Examines a twenty year period in the history of medicine, from 1879 to 1900, during which germ theory came to be accepted as common knowledge which totally transformed the field.