Today s Objectives: S.W.B.A.T.

Transcription

1 Today s Objectives: S.W.B.A.T. Review scale of universe powers of 10 significant digits Identify and discuss the 4 earliest civilizations and their contribution to astronomy past. Name two famous ancient observatories Discuss and calculate star distance and time it takes for light to travel various stars (calculations) H.W. Read over astronomy homework 1 check for questions/understanding

2 Activity: powers of 10 video clips Notes and discussion Assign homework 1 on Unit 1

3 Today s Objectives: S.W.B.A.T. Identify and discuss the 4 earliest civilizations and their contribution to astronomy past. Name two famous ancient observatories Describe early Greek cosmology Define geocentric view and why Greeks held this view Discuss Plato, Pythagoras, Aristotle, Eratosthenes

4 Activity: Notes/discussion Homework worksheet discuss

5 History of Astronomy Living in the Space Age, we have become accustomed to the modern view of our place in the universe. Images of our planet taken from space leave little doubt that Earth is round, and no one seriously questions the idea that we orbit the Sun. Yet there was a time, not so long ago, when some of our ancestors maintained that Earth was flat and lay at the center of all things. Our view of the universe and of ourselves has undergone a radical transformation since those early days. Earth has become a planet like many others, and humankind has been torn from its throne at the center of the cosmos and relegated to a rather unremarkable position on the periphery of the Milky Way Galaxy. But we have been amply compensated for our loss of prominence we have gained a wealth of scientific knowledge in the process. The story of how all this came about is the story of the rise of the scientific method and the genesis of modern astronomy.

6 People have always conducted their lives based on celestial observation and events or patterns in nature: Sunrise/sunset - day length Moon phases month Eclipses bad omen or evil Star motion daily and yearly clock and season Planets ( means to wander or wandering star ) - gods 5 visible planets from Earth can be seen with the unaided eye

7 Seasons suns position day length Comets death of high official, meteors (shooting stars) Supernova exploding stars very rare to observe

8 The concept of the organization and structure of the universe is called : cosmology Throughout history different ideas of the cosmos have changed with the advance of new technology.

9 Human survival depended on Astronomy in the past to become a good farmer the patterns and cycles of nature needed to be well understood. Seafarers needed to navigate their vessels (stars and charts)

10 4 past earliest civilizations China Hwang Ho River Arab Indus River Babylonia & Sumerian Tigris and Euphrates River Egypt Nile River All placed god like qualities to celestial objects Time and calendar were very important and had to be accurate

11 * Earliest most accurate calendar was provided by the Chinese - it had days How did they produce this accuracy? (What experiment? Or observation?) One possible: 1. Choose when the sun is highest or lowest position or point in the sky during the year June 21 or Dec. 21 solstice points 2. place a stick in ground so it has no shadow or mark shadow position (could have built a tower) 3. record time until no shadow or shadow on marked position 4. repeat experiment for many years

12 Babylonians & Arabs 40% - 50% constellation names came from Fertile crescent area of the Tigris and Euphrates River (present day Iraq) Cuneiform script Rosetta Stone Calendar based on the Moon - Babylonians (named of months told time or stage of planting)

13 Moon takes 29.5 days to go through 8 phases; they used this time to mark a month has passed and due to this fell short on year length (year length was around days) The high priest corrected this by having feast month or week each year or given time period

14 Egypt Land of the Nile the flooding of the Nile was very important it brought fertile silt and water to crops in the spring one star marked the time in the sky to start planting Sirius brightest star in the night sky ( when observed to rise exactly one hour before sunrise the Nile would start to flood (spring thaw)

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16 Pyramids where built in reference to the stars N, E, S, W (cardinal compass points) less than 1/12 degree in error Many line up to solstice and equinox points Example temple of Amen-Ra marks the beginning of Summer the last beam of light on the summer Solstice strikes the face of the statue

17 Writing hieroglyphics Their cosmology and gods Ra, sky god nut (noot)

18 Other ancient observatories: Stonehenge located in Salisbury Plain England, construction spans some 17 centuries, and it marks seasons, moon positions,?eclipses?

19 The Big Horn Medicine Wheel in Wyoming its builders the plains India Caracol Temple built by the Mayans around 1000 AD very accurate measurements of seasons and celestial events.

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