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Harmonices Mundi

Johannes Kepler · 1619

Kepler's 1619 book linking geometry, music and astronomy, in which he announced his third law of planetary motion.

Kepler wrote this book, in which he announced his third law of planetary motion.

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Title page of Johannes Kepler's Harmonices Mundi, 1619, printed in Linz, Austria. It lists the five books in Latin, shows a small woodcut vignette of a winged figure, and bears handwritten notes in pencil at lower left.
Johannes Kepler, title page of Harmonices Mundi, 1619.

About this source

What it is

Harmonices Mundi ("The Harmony of the World") is a Latin book written by Johannes Kepler and published in 1619 in Linz. It is divided into five books covering geometry, polyhedra, music theory, astrology and astronomy.

Why it matters

In its final section Kepler announced his third law of planetary motion, relating the time a planet takes to orbit the Sun to the size of its orbit. The book shows how Kepler combined mathematics, music theory and religious conviction into a single vision of the universe, seeing geometric and musical harmony in the motions of the planets. It reveals how deeply his science was tied to his belief in a divine, ordered cosmos.

Look closer

  • Why might a scientist of this era describe the planets' motions using musical terms like "soprano" and "bass"?
  • What does the small woodcut and the handwritten pencil notes on the title page suggest about how this book was used and kept over time?
  • How might Kepler's personal circumstances while writing this book have shaped his search for cosmic order?

This book is part of the curated material that grounds the AI version of Johannes Kepler on Humy.ai — when students ask about related events, the AI can quote it and cite it.

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Title page of Astronomia Nova, printed in Latin with mixed roman and italic capitals and a Greek subtitle. It reads Astronomia Nova, Aitiologetos, seu Physica Coelestis, on the motions of the star of Mars, from the observations of Tycho Brahe, by Johannes Kepler, Prague, 1609. A small library stamp appears at the lower left.Book

Secondary source

Astronomia Nova

Johannes Kepler · 1609

Title page of Kepler's Mysterium Cosmographicum in Latin, printed in Frankfurt by Erasmus Kempfer for Godefridus Tampachius, dated 1621 (MDCXXI) on this edition. Aged, brownish paper with a red library stamp at right.Book

Secondary source

Mysterium Cosmographicum

Johannes Kepler · 1596 (2nd edition 1621)

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Secondary source

The Martyrs of Science: Galileo, Tycho Brahe and Kepler

David Brewster

Two-page scan of an early 17th-century book: on the left, an engraved frontispiece of a domed rotunda with columns, astronomical instruments and figures, and a tablet reading Tabulae Rudolphinae; on the right, a title page in Latin with large capitals announcing Tabulae Rudolphinae by Johannes Kepler, dated 1627, with a red library stamp at top right.Book

Secondary source

Rudolphine Tables

Johannes Kepler · 1627

Scan of the title page of the book Epitome Astronomiae Copernicanae, printed in Latin in 1618 by Johannes Kepler, with the title, author line, publisher line, date MDCXVIII, and two library stamps at the bottom.Book

Primary source

Epitome Astronomiae Copernicanae

Johannes Kepler · 1618-1621

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