The Uncertain Heavens: Christiaan Huygens’ Ideas of E.T. Life in the 1680s

During the 17th century, as knowledge of the Universe and its contents increased, so did speculation about life on other planets. This article, The Uncertain Heavens: Christiaan Huygens’ Ideas of Extraterrestrial Life, was originally published in The Public Domain Review under a Creative Commons Attribution-ShareAlike 3.0. If you wish to reuse it please see: The author[…]

The Three Major Forms of Modern-Day Astrology

Thanks to the trend of publishing daily horoscopes in newspapers and magazines, every person in America knows about astrology. The general idea is that astrology calculates the position of the sun, moon, stars, and other celestial objects to determine the impact that can have on our everyday lives. However, most people are not aware of[…]

Ancient Greek Astronomy and Cosmology

A brief tour of some of the astronomical ideas and models from ancient Greece. Introduction As the stars move across the sky each night people of the world have looked up and wondered about their place in the universe. Throughout history civilizations have developed unique systems for ordering and understanding the heavens. Babylonian and Egyptian[…]

Comets, Omens, and Fear: Understanding Plague in the Middle Ages

In medieval times natural phenomena, such as comets and eclipses, were regarded as portents of natural disasters, including plagues. Introduction On August 30 2019, a comet from outside our solar system was observed by amateur astronomer Gennady Borisov at the MARGO observatory in Crimea. This was only the second time an interstellar comet had ever[…]

The Exile of Anaxagoras in Ancient Greece for Blaspheming the Moon

2,500 years ago, Anaxagoras correctly determined that the rocky moon reflects light from the sun, explaining lunar phases and eclipses. Close to the north pole of the moon lies the crater Anaxagoras, named for a Greek philosopher who lived in the fifth century B.C. The eponym is fitting, as Anaxagoras the man was one of[…]

Ancient Papyrus Horoscopes: Stars, Planets, and Fortunes

Heavenly bodies and human fate have long been perceived as intertwined. ‘The stars (…) disclose for men what will pertain to them from the time of their birth till their leaving the world’. This is what Dorotheus of Sidon, an astrologer who lived in 1st-century Alexandria, wrote at the beginning of his verse treatise on[…]

Astronomy in China since the Ancient World

China continues to be active in astronomy, with many observatories and its own space program. Introduction Astronomy in China has a very long history. Oracle bones from the Shang Dynasty (second millennium B.C.E.) record eclipses and novae. Detailed records of astronomical observations were kept from about the sixth century B.C.E. until the introduction of Western[…]

Galileo Galilei: A Scientific Break from Aristotle

The Catholic Church didn’t finally officially recognize their own error until John Paul II in 1992. Introduction Galileo Galilei (February 15, 1564 – January 8, 1642) was an Italian physicist, astronomer, and philosopher, whose career coincided with that of Johannes Kepler. His work constitutes a significant break from that of Aristotle and medieval philosophers and[…]

‘De Revolutionibus Orbium Coelestium’: The Medieval Copernican Revolution

His work marked the starting point of modern astronomy and cosmology. Introduction Nicolaus Copernicus (February 19, 1473 – May 24, 1543) was one of the great polymaths of his age. He was a mathematician, astronomer, jurist, physician, classical scholar, governor, administrator, diplomat, economist, and soldier. Amid his extensive accomplishments, he treated astronomy as an avocation.[…]

The 1900 Total Eclipse That Helped Prove Einstein’s Theory of Relativity

It was a matter of the right eclipse, the right place, and the right time. By Charles EmmersonHistorian and Author When Albert Einstein published the first draft of his general relativity theory in 1911, it predicted that light would bend when passing the gravitational pull of a large object. To verify his calculations, he needed[…]

Exploring Our Moon and Learning about Earth’s Youth Billions of Years Ago

The moon might harbor bits of the Earth that blasted off our planet billions of years ago that hold secrets about our home. Introduction The surface of the Earth preserves little or no information about its distant past. Constant tectonic activity has recycled Earth’s crust and shifted landmasses. Rainfall, wind, ice and snow have weathered[…]

Written in the Stars: Astronomy and Astrology in Medieval Manuscripts

Faith, science, and stargazing influenced everyday decisions in the Middle Ages. Introduction Humankind has always looked to the sky in wonder, with a desire to understand our place in the universe. Eclipses, comets, and star and planet sightings mesmerize us and inspire awe. In the medieval world, from about 500 to 1500, astronomy was a[…]

Astronomy in Pre-Columbian Mesoamerica

The observation of the sky was of considerable importance to the Maya, Aztecs and other prehisanic peoles of Mesoamerica. Overview The observation of the sky was of considerable importance to the Maya, Aztecs and other prehispanic peoles of Mesoamerica. Their familiarity with the regularities of the apparent motion of the Sun, the Moon and bright[…]

Ancient Cosmologies: Understanding Ancient Skywatchers, Mayas, and their Worldviews

Since the beginning of humankind, the fascination with the celestial vault has been regarded as an important element in human life, their future, and history. Overview Ancient and pre-modern worldviews of the cosmos originated in practical lifeworld structures and experiences and therefore cannot be analyzed in the same manner as modern cosmologies are. Being embedded[…]