Celestial spheres in the context of "Nicholas Copernicus"

Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a model of the universe that placed the Sun rather than Earth at its center. The publication of Copernicus's model in his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), just before his death in 1543, was a major event in the history of science, triggering the Copernican Revolution and making a pioneering contribution to the Scientific Revolution. Though a similar heliocentric model had been developed eighteen centuries earlier by Aristarchus of Samos, an ancient Greek astronomer, Copernicus likely arrived at his model independently.

Copernicus was born and died in Royal Prussia, a semiautonomous and multilingual region created within the Crown of the Kingdom of Poland from lands regained from the Teutonic Order after the Thirteen Years' War.

Aristotelian physics is the form of natural philosophy described in the works of the Greek philosopher Aristotle (384–322 BC). In his work Physics, Aristotle intended to establish general principles of change that govern all natural bodies, both living and inanimate, celestial and terrestrial – including all motion (change with respect to place), quantitative change (change with respect to size or number), qualitative change, and substantial change ("coming to be" [coming into existence, 'generation'] or "passing away" [no longer existing, 'corruption']). To Aristotle, 'physics' was a broad field including subjects which would now be called the philosophy of mind, sensory experience, memory, anatomy and biology. It constitutes the foundation of the thought underlying many of his works.

Key concepts of Aristotelian physics include the structuring of the cosmos into concentric spheres, with the Earth at the centre and celestial spheres around it. The terrestrial sphere was made of four elements, namely earth, air, fire, and water, subject to change and decay. The celestial spheres were made of a fifth element, an unchangeable aether. Objects made of these elements have natural motions: those of earth and water tend to fall; those of air and fire, to rise. The speed of such motion depends on their weights and the density of the medium. Aristotle argued that a vacuum could not exist as speeds would become infinite.

The tree of life (Hebrew: עֵץ חַיִּים, romanized: ʿēṣ ḥayyim or no: אִילָן‎, romanized: ʾilān, lit. 'tree') is a diagram used in Rabbinical Judaism in kabbalah and other mystical traditions derived from it. It is usually referred to as the "kabbalistic tree of life" to distinguish it from the tree of life that appears alongside the tree of the knowledge of good and evil in the Genesis creation narrative as well as the archetypal tree of life found in many cultures.

Simo Parpola asserted that the concept of a tree of life with different spheres encompassing aspects of reality traces its origins back to the Neo-Assyrian Empire in the ninth century BCE. The Assyrians assigned moral values and specific numbers to Mesopotamian deities similar to those used in Kabbalah and claims that the state tied these to sacred tree images as a model of the king parallel to the idea of Adam Kadmon. However, J. H. Chajes states that the ilan should be regarded as primarily indebted to the Porphyrian tree and maps of the celestial spheres rather than to any speculative ancient sources, Assyrian or otherwise.

Nous (UK: /naʊs/, US: /nuːs/), from Ancient Greek: νοῦς, is a concept from classical philosophy, sometimes equated to intellect or intelligence, for the faculty of the human mind necessary for understanding what is true or real.

Alternative English terms used in philosophy include "understanding" and "mind"; or sometimes "thought" or "reason" (in the sense of that which reasons, not the activity of reasoning). It is also often described as something equivalent to perception except that it works within the mind ("the mind's eye"). It has been suggested that the basic meaning is something like "awareness". In colloquial British English, nous also denotes "good sense", which is close to one everyday meaning it had in Ancient Greece. The nous performed a role comparable to the modern concept of intuition.

Salvator Mundi (Latin for 'Savior of the World') is a painting attributed in whole or part to the Italian High Renaissance artist Leonardo da Vinci, dated c. 1499–1510. Long thought to be a copy of a lost original veiled with overpainting, it was rediscovered, restored, and included in an exhibition of Leonardo's work at the National Gallery, London, in 2011–2012. Christie's, which sold the work in 2017, stated that most leading scholars consider it an original work by da Vinci, but this attribution has been disputed by some leading specialists, some of whom propose that he only contributed certain elements; others believe that the extensive restoration prevents a definitive attribution.

The painting depicts Jesus Christ in anachronistic blue Renaissance attire, making a gesture of blessing with his right hand, while holding a transparent, non-refracting crystal orb in his left, signalling his role as Salvator Mundi and representing the celestial sphere of the heavens. Approximately thirty copies and variations of the work by pupils and followers of Leonardo have been identified; two are considered to have been produced during Leonardo's lifetime. Two preparatory chalk and ink drawings of the drapery by Leonardo are held in the British Royal Collection.

The 16th century begins with the Julian year 1501 (MDI) and ends with either the Julian or the Gregorian year 1600 (MDC) (depending on the reckoning used; the Gregorian calendar introduced a lapse of 10 days in October 1582). The Habsburg Spanish Empire, Portuguese Empire, Ottoman Empire, Safavid Persia, Mughal India and Ming China were the most powerful and hegemonic states.

The Renaissance in Italy and Europe saw the emergence of important artists, authors and scientists, and led to the foundation of important subjects which include accounting and political science. Copernicus proposed the heliocentric universe, which was met with strong resistance, and Tycho Brahe refuted the theory of celestial spheres through observational measurement of the 1572 appearance of a Milky Way supernova. These events directly challenged the long-held notion of an immutable universe supported by Ptolemy and Aristotle, and led to major revolutions in astronomy and science. Galileo Galilei became a champion of the new sciences, invented the first thermometer and made substantial contributions in the fields of physics and astronomy, becoming a major figure in the Scientific Revolution in Europe.

In astronomy, axis mundi is the Latin term for the axis of Earth between the celestial poles. In a geocentric coordinate system, this is the axis of rotation of the celestial sphere. Consequently, in ancient Greco-Roman astronomy, the axis mundi is the axis of rotation of the planetary spheres within the classical geocentric model of the cosmos.

In 20th-century comparative mythology, the term axis mundi – also called the cosmic axis, world axis, world pillar, center of the world, or world tree – has been greatly extended to refer to any mythological concept representing "the connection between Heaven and Earth" or the "higher and lower realms". Mircea Eliade introduced the concept in the 1950s. Axis mundi closely relates to the mythological concept of the omphalos (navel) of the world or cosmos.Items presented as examples of the axis mundi by comparative mythologists include plants (notably a tree but also other types of plants such as a vine or stalk), a mountain, a column of smoke or fire, or a product of human manufacture (such as a staff, a tower, a ladder, a staircase, a maypole, a cross, a steeple, a rope, a totem pole, a pillar, a spire). Its proximity to heaven may carry implications that are chiefly religious (pagoda, Temple Mount, minaret, church) or secular (obelisk, lighthouse, rocket, skyscraper). The image appears in religious and secular contexts. The axis mundi symbol may be found in cultures utilizing shamanic practices or animist belief systems, in major world religions, and in technologically advanced "urban centers". In Mircea Eliade's opinion: "Every Microcosm, every inhabited region, has a Centre; that is to say, a place that is sacred above all."

In Greek mythology, Atlas (/ˈætləs/; Ancient Greek: Ἄτλας, Átlās) is a Titan condemned to hold up the heavens or sky for eternity after the Titanomachy. Atlas also plays a role in the myths of two of the greatest Greek heroes: Heracles (Hercules in Roman mythology) and Perseus. According to the ancient Greek poet Hesiod, Atlas stood at the ends of the earth in the extreme west. Later, he became commonly identified with the Atlas Mountains in northwest Africa and was said to be the first King of Mauretania (modern-day Morocco and west Algeria, not to be confused with the modern-day country of Mauritania). Atlas was said to have been skilled in philosophy, mathematics, and astronomy. In antiquity, he was credited with inventing the first celestial sphere. In some texts, he is even credited with the invention of astronomy itself.

Atlas was the son of the Titan Iapetus and the Oceanid Asia or Clymene. He was a brother of Epimetheus and Prometheus. He had many children, mostly daughters, the Hesperides, the Hyades, the Pleiades, and the nymph Calypso who lived on the island Ogygia.