Ten milestones that have helped to tell life's story: Walter Alvarez's asteroid theory of dinosaur extinction, the first identification of dinosaur...

Twelve landmark steps to understanding the Earth's structure: Richard Oldham's theory of a liquid core, Inge Lehmann's conclusion that the core is...

Thirteen discoveries that help explain why matter and energy behave as they do: Galileo's law of falling bodies, Isaac Newton's conclusions of...

Thirteen achievements in medicine: Andreas Vesalius's anatomical charts, William Harvey's breakthrough on blood circulation, Karl Landsteiner's...

Thirteen crucial benchmarks in the history of what may be the oldest science: Ancient awareness that the planets move, Copernican cosmology, Johannes...

Thirteen building blocks in a science that may be the foundation of the modern world: Joseph Priestly and Antoine Lavoisier's discovery of oxygen,...

Thirteen breakthroughs in the science of living things: Anton van Leeuwenhoek's discovery of micro-organisms, Robert Brown's identification of cell...

Thirteen vital contributions to a field tht is now a cornerstone of the life sciences: Gregor Mendel's rules of heredity, Thomas Hunt Morgan's...