Exploring the Planets: Copernicus

Stone Hedge

Sun rises directly over the "heel stone" on the longest day of the year

Stone Medicine Wheels

Central cairn and outer ring connected by spokes that correspond to the rising/setting sun and certain stars

El Caracol

Acient building with windows that align with significant astronomical events for the Mayan people

Machu Picchu

Citadel with an observatory that aligned with the rising sun on the solstice

Temple of Amun-Ra

During sunrise on the winter solstice, the sun sits right at the entrance

Number of constellations

88, the Greeks named 48 of them

Thales

Created the first known model of the universe not rooted in the supernatural and said Earth was a flat disk floating in an infinite ocean

Anaximander

Introduced the celestial sphere

Pythagoras

Said earth is a sphere and planets, sun and moon have their own motion

Heraclides

Said Earth rotates on its axis once a day

Aristotle

Classified motion as voluntary, natural and forced and said objects will remain at rest until a force acts upon them

Euclid's Postulates

1. Given two points, there is a line that passes through them 2. A line segment can extend on both sides to form a line 3. A circle can be drawn ay any point if given a centre and a radius 4. All right angles are congruent to each other 5. For every line and every point that does not exist on the line, there can be made a parallel line

Aristarchus

Suggested the sun is the centre of the universe and calculated it to be larger and father away than the earth

Erastothenus

Computed the Earth's circumference using a stick in two cities and the time when it had no shadow on the solstice (measured 40,000km which is accurate)

Geocentrism

Earth is the centre of the universe and epicycles are used to account for retrograde motion

Retrograde motion

Apparent opposite direction motion of celestial bodies (happens when one planets passes another in orbit)

Ptolemy

Came up with epicycles to explain retrograde motion, where planets spin in loops as they orbit the earth

Law of Parsimony

The simplest explanation is the best one

Heliocentrism

Sun is at the centre of the universe and stationary with correct order of planets that have circular orbits

Copernicus

Proved the heliocentrism model and named the planets inferior or superior

Inferior planets

Mercury, Venus

Superior planets

Mars, Jupiter, Saturn

Superior conjunction

The sun passes between earth and a planet

Inferior conjunction

A planet passes between the earth and the sun

Opposition

The earth passes between a planet and the sun

Quadrature

the earth form s a 90 degree angle with the sun and a planet

Greatest elongation

A planet forms a 90 degree angle with the sun and earth

Brahe

Noticed a supernova and was not able to use parallax to determine how far away it was so he suggested a hybrid model of the universe where the sun and moon revolve around the earth and all other planets revolve around the sun

Kepler

Discovered planetary motion and made 3 laws about it

Law of Ellipses

Kepler's law stating planets move in ellipses, not circled and the sun is one of the foci in an oval

Law of Equal Areas

Kepler's law stating if we draw a line from the sun to a planet at two different points and measure area over time, it will be the same or any two points, therefore the closer to the sun a planet is, the faster it is moving

Law of Harmony

Kepler's law stating orbital period is proportional to the distance from the sun (T^2 is proportional to R^3)

Galileo

First European to use a telescope. Determined Venus went though phases like the moon so it must orbit the sun, said planets are circular discs, discovered craters on the moon, discovered sunspots and created a model of movement for interia

Interia

An object in motion stays in motion

Newton

Created laws of motion to explain how forces affected objects and used F=ma to prove the Earth orbited the sun (if the sun has more mass, earth has more acceleration if F=F)

Law of Inertia

Newton's law stating an object will stay at rest or in motion unless another force acts on it

Law of Acceleration

Newton's law stating force acting on an object=mass x acceleration (F=ma)

Law of Equal and Opposite Force

Newton's law stating when an object acts on an object, the second object exerts an equal force back against the first object

Law of Mutual Gravitation

F=[G(m1)(m2)]/R^2