More Related Content
Similar to Introduction to Astronomy Notes (20)
More from mgitterm (20)
Introduction to Astronomy Notes
- 2. The scientific study of the universe Astronomy:
- 3. Originally suggested the universe had a large stationary Earth in the center, and the sun, moon, and the stars were arranged around the Earth in perfect spheres orbiting in perfect or constant speeds OriginalThoughts:
- 5. As careful mathematical observations were made, they found the Sun, the Moon, and some of the “stars” did not follow paths as thoughts OriginalThoughts
- 6. The “stars” that did not follow the predicted path, rather they “wandered” across the sky, and thus were called “planets”, the Greek word for “wander” OriginalThoughts
- 7. Aristotle’sTheories: • The Earth was in the center, and the Sun, the Moon, the stars, and the planets orbited on separate spheres that encased each other and spun at different rates • Motion caused by a supernatural being • Earth was a sphere (could see shadow on moon during eclipse) and non-moving (because we could not feel it and falling objects would not drop straight down)
- 8. Earth centered, model of the Universe Geocentric Universe:
- 9. Retrograde Motion: A problem with Aristotle’s theory was that objects would travel one direction across, the sky, stop, and go backwards
- 10. Ptolemy’sTheories: • Geo-centric • Each planet was fixed to a small sphere that was fixed to a larger sphere • No changes made for a 1,000 years until the inaccuracies in predictions became to big to blame on primitive equipment
- 11. Copernicus’Theories • Proposed a sun-centered universe with the Earth spinning on its axis once a day • Orbits were perfect circles • Did not publish his findings until his death because it contradicted the Church’s beliefs
- 13. Tycho Brahe’s Contribution Built a top of line observatory, gathered and kept tremendous amounts of data
- 14. Johannes Kepler’sTheories Laws of Planetary Motion: • Each planet revolves around the Sun in an elliptical orbit with the sun at one of the foci • Planets do not move at a constant velocity (due to gravity pulling) • There is a mathematical relationship between the time it takes a planet to revolve around the sun and its average distance from the sun
- 15. Galileo Galilei’s Contribution Developed and refined the telescope for view distant objects
- 16. Explosion of matter that occurred 14 billion years ago, and thus the universe expanding since that point Big BangTheory:
- 18. Universe: The entirety of what we call outer space
- 19. A collection of stars, dust, and gas bound together by gravity (ours is the Milky Way Galaxy) Galaxy
- 20. A collection of planets that revolve around a star (sun) Solar System
- 21. The average distance between the Earth and the sun; approximately 150 million kilometers Astronomical Unit:
- 22. The speed of light is 300,000 km/s Light Speed
- 23. The distance that light can travel in one year (9.46 km x 1012) LightYear
- 24. All the frequencies or wavelengths of electromagnetic waves (energy) Electromagnetic Spectrum
- 26. Notes on the Elec. Spec. • What we see falls into the visible light spectrum • Only stars emit visible light, everything else (planets & moons) are reflecting light • Other instruments can detect the other electromagnetic waves
- 27. An instrument that collects electromagnetic radiation from the sky and concentrates it for better observation Telescopes
- 28. Telescopes that only collect visible light OpticalTelescopes
- 29. RefractingTelescope: Uses a set lenses to focus light ReflectingTelescope: Uses a set of mirrors to focus light OpticalTelescopes
- 30. Used to detect radio waves, gamma rays, and infrared rays Invisible Electromagnetic Radiation Telescopes
- 31. Telescopes that were launched into space to escape obstructive Earth’s atmosphere (HubbleTelescope) SpaceTelescopes