Setting
In the world of Celestial Matters, Ptolemaic astronomy and Aristotelian physics are valid scientific models of the surrounding world and cosmos. The Earth lies at the center of the universe, surrounded by crystal spheres which hold each of the planets, the sun and the moon, all enclosed in the sphere of the fixed stars. Earthly matter, composed of the classical four elements of earth, air, fire, and water, naturally moves in straight lines. Heavenly matter naturally rises and moves in circles. This is the universe as understood by the ancient Greeks.
The science of the ancient Chinese also applies, but as the novel is told from the perspective of the Greeks, it is less well-understood. Xi, the Chinese notion of spirit and flow, can be manipulated to move objects and energy. The Chinese five elements of earth, metal, water, wood, and fire are transmuted one into the other. Part of the central theme of the book is the two system's mutual misunderstanding and bafflement of each other.
In this world, the Delian League (Greeks) and Middle Kingdom (Chinese) have been fighting a war for nearly a thousand years, ever since the time of Alexander the Great when the warrior-culture of Sparta and the Athenian Akademe were fused into a half-world conquering force. Their technologies are locked together, however, and neither empire can gain the upper hand. Each side secretly despairs of its chances and has come to consider desperate measures.
Plot summary
The story is narrated by Aias of Tyre, a scientist of the Delian League, who is preparing to embark on Project Sunthief as scientific commander. This project is an audacious and desperate mission to sail a spaceship carved out of a piece of the moon herself out through the spheres, to catch a piece of the sun and bring it back to earth to annihilate the Middler capital city. This, the league hopes, will finally end the war and give it victory.
The Middlers have been assassinating Delian generals and politicians, so Aias is assigned a bodyguard, Captain Yellow Hare of Sparta, a woman of Xeroki ancestry. Shortly after the launch of the moon-ship, Chandra's Tear, it becomes clear that there is a saboteur on board. Aias' old friend Ramonojon, a mathematician, has expressed doubts about the rightness of annihilating an entire city and is viewed with dark suspicion by Anaxamander, the heroic military commander of the project. Mihradarius, the fire scientist who has devised the sun-catching method, keeps his own counsel.
As sabotage, catastrophe, and exhilarating maneuvers overtake the voyage, Aias begins to wonder about the wisdom of the Delian strategy. Eventually he comes to understand the desperation of the Middle Kingdom, thanks to a Middler scientist stowaway, and they try to synthesize between them a way for the two world-spanning empires to resolve their differences. There remains a life-or-death race to earth on a crippled ship in the hope of bringing hope.
Flat Earth is an archaic and scientifically disproven conception of the Earth's shape as a plane or disk. Many ancient cultures subscribed to a flat-Earth cosmography.
Astronomy is the oldest of the natural sciences, dating back to antiquity, with its origins in the religious, mythological, cosmological, calendrical, and astrological beliefs and practices of prehistory: vestiges of these are still found in astrology, a discipline long interwoven with public and governmental astronomy. It was not completely separated in Europe during the Copernican Revolution starting in 1543. In some cultures, astronomical data was used for astrological prognostication.
The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since the Big Bang. While the spatial size of the entire universe is unknown, it is possible to measure the size of the observable universe, which is approximately 93 billion light-years in diameter at the present day.
The cosmos is another name for the Universe. Using the word cosmos implies viewing the universe as a complex and orderly system or entity.
Astronomy is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole.
This timeline of cosmological theories and discoveries is a chronological record of the development of humanity's understanding of the cosmos over the last two-plus millennia. Modern cosmological ideas follow the development of the scientific discipline of physical cosmology.
In astronomy, the geocentric model is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, and planets all orbit Earth. The geocentric model was the predominant description of the cosmos in many European ancient civilizations, such as those of Aristotle in Classical Greece and Ptolemy in Roman Egypt. Ptolemy’s geocentric model was adopted and refined during the Islamic Golden Age, which Muslims believed correlated with the teachings of Islam.
An armillary sphere is a model of objects in the sky, consisting of a spherical framework of rings, centered on Earth or the Sun, that represent lines of celestial longitude and latitude and other astronomically important features, such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations. It was invented separately first in ancient China during the 4th century BC and ancient Greece during the 3rd century BC, with later uses in the Islamic world and Medieval Europe.
Spherical Earth or Earth's curvature refers to the approximation of figure of the Earth as a sphere. The earliest documented mention of the concept dates from around the 5th century BC, when it appears in the writings of Greek philosophers. In the 3rd century BC, Hellenistic astronomy established the roughly spherical shape of Earth as a physical fact and calculated the Earth's circumference. This knowledge was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages. A practical demonstration of Earth's sphericity was achieved by Ferdinand Magellan and Juan Sebastián Elcano's circumnavigation (1519–1522).
The cosmological model of concentricspheres, developed by Eudoxus, Callippus, and Aristotle, employed celestial spheres all centered on the Earth. In this respect, it differed from the epicyclic and eccentric models with multiple centers, which were used by Ptolemy and other mathematical astronomers until the time of Copernicus.
The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the apparent motions of the fixed stars and planets are accounted for by treating them as embedded in rotating spheres made of an aetherial, transparent fifth element (quintessence), like jewels set in orbs. Since it was believed that the fixed stars did not change their positions relative to one another, it was argued that they must be on the surface of a single starry sphere.
In astronomy, the fixed stars are the luminary points, mainly stars, that appear not to move relative to one another against the darkness of the night sky in the background. This is in contrast to those lights visible to naked eye, namely planets and comets, that appear to move slowly among those "fixed" stars.
The Wind from the Sun (ISBN 0-15-196810-1) is a 1972 collection of science fiction short stories by British writer Arthur C. Clarke. Some of the stories originally appeared in a number of different publications. A part of the book was included in CD on board the Planetary Society's solar sail, Cosmos 1.
On the Heavens is Aristotle's chief cosmological treatise: written in 350 BC, it contains his astronomical theory and his ideas on the concrete workings of the terrestrial world. It should not be confused with the spurious work On the Universe.
Cosmology is a branch of physics and metaphysics dealing with the nature of the universe. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis. Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology. In the science of astronomy, cosmology is concerned with the study of the chronology of the universe.
The Ray of Creation is an esoteric cosmology which was taught by G. I. Gurdjieff. It is a diagram which better represents the place which Earth occupies in the Universe. The diagram has eight levels, each corresponding to Gurdjieff's Law of Octaves.
In Aristotelian physics and Greek astronomy, the sublunary sphere is the region of the geocentric cosmos below the Moon, consisting of the four classical elements: earth, water, air, and fire.
Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the Ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the language of scholarship throughout the Hellenistic world following the conquests of Alexander. This phase of Greek astronomy is also known as Hellenistic astronomy, while the pre-Hellenistic phase is known as Classical Greek astronomy. During the Hellenistic and Roman periods, much of the Greek and non-Greek astronomers working in the Greek tradition studied at the Museum and the Library of Alexandria in Ptolemaic Egypt.
Islamic cosmology is the cosmology of Islamic societies. It is mainly derived from the Qur'an, Hadith, Sunnah, and current Islamic as well as other pre-Islamic sources. The Qur'an itself mentions seven heavens.
An astronomical system positing that the Earth, Moon, Sun, and planets revolve around an unseen "Central Fire" was developed in the fifth century BC and has been attributed to the Pythagorean philosopher Philolaus. The system has been called "the first coherent system in which celestial bodies move in circles", anticipating Copernicus in moving "the earth from the center of the cosmos [and] making it a planet". Although its concepts of a Central Fire distinct from the Sun, and a nonexistent "Counter-Earth" were erroneous, the system contained the insight that "the apparent motion of the heavenly bodies" was due to "the real motion of the observer". How much of the system was intended to explain observed phenomena and how much was based on myth, mysticism, and religion is disputed. While the departure from traditional reasoning is impressive, other than the inclusion of the five visible planets, very little of the Pythagorean system is based on genuine observation. In retrospect, Philolaus's views are "less like scientific astronomy than like symbolical speculation."
