Ancient Astronomy, Planetary Models, and Philosophy of Society and Death

Flashcard deck containing vocabulary terms, historical models, scientific principles, and philosophical concepts from lecture material covering ancient astronomy, celestial mechanics, social theories, and philosophical perspectives on mortality.

Diurnal Motion

The daily motion of celestial bodies caused by Earth's rotation on its axis from west to east every $24\,\text{hours}$, making objects appear to rise in the east.

Meridian

The highest point in the sky crossed by a celestial object during its apparent daily path.

Annual Motion

The yearly apparent motion of the Sun and stars caused by Earth's revolution around the Sun.

Thales

An early Greek thinker who proposed that Earth hangs freely in space.

Anaximander

An early philosopher who proposed that Earth is cylindrical in shape.

Pythagoras

A Greek philosopher who believed universal truth is expressed through mathematics, stated that the Sun, Moon, and Earth are spherical, recognized Venus as both the morning and evening star, and proposed that Earth and the Sun move around a central fire.

Aristarchus

An ancient Greek astronomer who was the first to propose a heliocentric model of the universe.

Eratosthenes

An ancient Greek scholar who accurately calculated Earth's circumference.

Anaxagoras

A Greek thinker who determined the relative positions of the Earth, Sun, and Moon during eclipses.

Aristotle's Two Domains

The cosmological division consisting of the celestial domain, made of perfect ether moving in circular motion, and the imperfect terrestrial domain, composed of earth, water, air, and fire driven by a tendency toward perfection.

Ether

The fifth element that Aristotle posited made up the celestial domain, characterized by perfection and eternal circular motion.

Natural Motion

In Aristotelian physics, the terrestrial motion determined by the natural tendencies of the four elements (earth, water, air, and fire).

Voluntary and Involuntary Motion

Aristotle's categorization where voluntary motion characterizes humans and animals, whereas involuntary motion characterizes plants and minerals.

Plato's Cosmological Principle

The philosophical emphasis on mathematical symmetries and perfect geometric shapes, specifically the sphere and circle, to describe celestial motions.

Eudoxian Planetary System

A geocentric model featuring $27$ concentric spheres: three spheres each assigned to the Sun and Moon, and four spheres assigned to each of the five known planets.

Hipparchus

The ancient Greek astronomer considered the founder of trigonometry who cataloged and recorded $46\text{ to }48$ constellations.

Constellation

A recognizable pattern of stars in the night sky. There are $88$ officially recognized modern constellations, $48$ of which were identified by ancient Greeks.

Ptolemaic Model

The geocentric planetary system proposed by Claudius Ptolemy with Earth at the center, accepted for approximately $1400\,\text{years}$.

Tychonic System

A geo-heliocentric system proposed by Tycho Brahe in which Earth is motionless at the center, orbited by the Sun and Moon, while the other planets orbit the Sun.

Copernican System

A heliocentric system proposed by Nicolaus Copernicus placing the Sun at the center of the planetary orbits, with only the Moon orbiting Earth in circular paths.

Kepler's First Law (Law of Ellipses)

The astronomical law stating that planetary orbits are ellipses with the Sun situated at one focus.

Radius Vector

The imaginary straight line connecting the Sun to an orbiting planet.

Kepler's Second Law (Law of Equal Areas)

The principle stating that a planet's radius vector sweeps out equal areas in equal times, moving fastest at perihelion and slowest at aphelion.

Perihelion and Aphelion

The points in a planet's elliptical orbit where it is closest to the Sun (moving fastest) and farthest from the Sun (moving slowest), respectively.

Kepler's Third Law (Law of Periods)

The harmonic law stating that the ratio of the cube of the orbital radius to the square of the orbital period is constant: $\frac{r^3}{T^2} = \text{constant}$.

Umbra

The darkest, central part of a shadow where all direct light from the illuminating source is completely blocked.

Penumbra

The lighter, outer region of a shadow where light is only partially obscured.

Antumbra

The area beyond the umbra where the obscuring body appears entirely within the disc of the light source, leaving a visible outer boundary.

Solar Eclipse

An astronomical alignment where the Moon passes directly between the Sun and Earth, casting its shadow upon Earth.

Total Solar Eclipse

An eclipse occurring when the Moon completely blocks the Sun's bright disk, revealing the Sun's outer corona.

Annular Eclipse

A solar eclipse occurring when the Moon's antumbra reaches Earth, leaving a bright luminous circle visible, known as the 'Ring of Fire'.

Hybrid Eclipse

A rare solar eclipse that shifts along its path between an annular eclipse and a total solar eclipse.

Lunar Eclipse

An astronomical event where Earth lies directly between the Sun and Moon; in a total lunar eclipse, the Moon may turn reddish, while in a penumbral eclipse, only Earth's penumbra touches the Moon.

Synodic Month

The complete cycle of lunar phases caused by changing relative positions of the Earth, Sun, and Moon, lasting approximately $29.5\,\text{days}$.

Waxing and Waning

Terms describing the changing lunar phases: waxing refers to an increasing illuminated portion, whereas waning refers to a decreasing illuminated portion.

Equinox

An astronomical occurrence happening twice a year when day and night are of nearly equal duration worldwide, such as the vernal equinox around March 21.

Solstice

An astronomical event marking the extremes of day length, including the summer solstice (longest day of the year) and winter solstice (occurring around December 21).

Meteor Showers

Astronomical events named after the constellation from which they appear to radiate, such as the Quadrantids (December/January), Perseids (August), and Leonids (November).

Conjunction

An astronomical configuration in which two or more celestial bodies appear close together in the sky.

Inferior Conjunction

The alignment where an inferior planet lies directly between Earth and the Sun, which may result in an astronomical transit.

Superior Conjunction

The configuration where a planet is located on the opposite side of the Sun from Earth.

Opposition

A configuration where a planet is directly opposite the Sun from Earth's vantage point, causing the planet to rise at sunset, set at sunrise, and appear at its brightest and largest.

Elongation

The angular distance between a planet and the Sun as viewed from Earth, categorized into eastern elongation (visible in the evening after sunset) and western elongation (visible in the morning before sunrise).

Society

A lasting group of individuals who develop organized relationships and interactions with one another.

Social Units

The hierarchical levels of human organization ordered from smallest to largest: individual, family, community, nation, and world.

Beliefs

Accepted opinions held by members of a group that provide common sentiments and foster a sense of belonging.

Norms

Accepted and shared rules or patterns of behavior expected within a given social system.

Status

A recognized social position or rank occupied by an individual within a society.

Roles

The expected behaviors and obligations associated with a particular status or position in society.

Authority

The legitimate power exercised over members of a group to prevent conflict and maintain social order.

Sanction

A form of punishment or enforcement mechanism applied by a social system to deter deviant behavior.

Folkways

Traditional customs and informal conventions practiced routinely within a culture.

Laws

Formal, codified, and binding rules enacted by an authority to regulate conduct and promote social harmony.

State of Nature

A hypothetical pre-political condition characterized by complete freedom where competing desires inevitably produce conflict and war.

Social Contract

An explicit or implicit agreement among individuals who surrender certain liberties in exchange for social order, laws, and protection of their lives, remaining liberties, and properties by government.

Thomas Hobbes's Social Contract

The view that human nature in the state of nature is inherently selfish and distrustful, making a totalitarian government with absolute power necessary to maintain peace.

John Locke's Social Contract

A political philosophy emphasizing human reason in the state of nature, asserting that government's main purpose is to protect natural rights, sovereignty resides in the people, and controversies are settled by established laws and judges.

General Will

Jean-Jacques Rousseau's concept of the collective interest that binds members of political society to protect their lives, goods, and liberty.

Nomadic Society

A mobile society whose members survive primarily through hunting and gathering while continuously moving between places.

Pastoral Society

A historical society characterized primarily by the domestication and herding of animals, emerging contemporaneously with horticultural societies.

Horticultural Society

A society based on cultivating plants and vegetables using simple tools, frequently relocating as local resources become scarce.

Agricultural Society

A society centered on crop and animal farming whose increased food supplies initiated a revolution, during which farmers traded food for warrior protection and women became subordinate.

Industrial Society

A society marked by the invention of steam engines and mechanized factories, leading to increased productivity, larger cities, cultural diversity, and expanded trade and transportation.

Postindustrial Society

A modern society driven by technology where access to information serves as the dominant feature.

Virtual Society

A non-physical social space in cyberspace made possible by the internet and social media, free from territorial and geographical boundaries.

Bourgeoisie

In Karl Marx's analysis, the landowning and property-owning capitalist class that abuses and exploits working-class wage earners.

Proletariat

In Marxist theory, the wage-earning working class who are subjected to exploitation and abuse by the bourgeoisie.

Capitalist Society

An economic and social system founded on private ownership of businesses, where owners and bosses receive the majority of profits.

Utopian Society

Marx's yet-to-be-achieved ideal communist society lacking private property, defined by shared ownership, short equal work hours, and free goods.

Bucket List

A personal collection of experiences and activities (such as traveling, adventuring, and spending time with loved ones) an individual aims to accomplish before dying.

Organ Donation Act

The Philippine legislation defining legal death as the irreversible cessation of circulatory and respiratory functions, or the irreversible cessation of all functions of the entire brain.

Legal Death

The clinical and legal status established by the irreversible cessation of circulatory and respiratory functions or the irreversible cessation of all brain functions, deemed to occur when functions ceased after failed resuscitation.

Reincarnation

The philosophical or spiritual belief that the soul enters a new life after physical death.

Socrates' View on Death

The position that death is either an eternal, dreamless sleep or a transition to another life; because neither outcome is harmful, death need not be feared.

Epicurus' View on Death

The philosophical argument that all sensation and consciousness cease at death, meaning the dead feel no pain; since we no longer exist when death arrives, death is 'nothing to us'.

Thomas Nagel's View on Death

The deprivation account asserting that death is an evil solely because it deprives a person of future possibilities and life experiences, identifying premature dying as the only real evil.