- home
- Mechanics
- Kinematics
- Dynamics I: Force
- Energy
- Dynamics II: Momentum
- Rotational Motion
- Planetary Motion
- Periodic Motion
- Fluids
- Thermal Physics
- Heat & Temperature
- Calorimetry
- Heat Transfer
- Thermodynamics
- Waves & Optics
- Wave Phenomena
- Sound
- Physical Optics
- Geometric Optics
- Electricity & Magnetism
- Electrostatics
- Electrostatic Applications
- Electric Current
- DC Circuits
- Magnetostatics
- Magnetodynamics
- AC Circuits
- Electromagnetic Waves
- Modern Physics
- Relativity
- Quanta
- Wave Mechanics
- Nuclear Physics
- Particle Physics
- Appendices
- Units
- Measurement
- Graphs
- Vectors
- Reference
- about
- news
- shop
- contact
- more
-
✚ share
-
Geocentrism
Summary
- the ancient solar system consists of …
- a night sky filled with hundreds of fixed stars that …
- remain in the same positions relative to one another
- appear to belong to groups called constellations named after supernatural beings
- rotate as a group across the sky about once every day
- shift gradually in the sky when viewed at the same time from night to night
- return to their original positions relative to the horizon after one year
- two primary moving objects …
- sun
- moves across the sky once every day
- moves across the background of the fixed stars once every year
- moon
- moves across the sky about once a every day
- cycles through apparent changes (called phases) roughly once every month
- five planets visible to the unaided eye
- named in English after gods of the Ancient Rome
- mercury
- venus
- mars
- jupiter
- saturn
- wander across the background sky of fixed stars
- generally moving in the same direction as the sun, moon, and stars
- but occasionally moving backward (retrograde)
- a total of seven moving objects each of which is associated with a day of the week in English and other languages
