Unit # 2
Space Exploration – Class 1 Notes Handout
Haiku on Heavens:
Beautiful clear sky
Many wonders to be found
This world discovered
Developing Ideas about the “Heavens”
First Nations Story of the Sky:
•Thought the night sky was a pattern on a great blanket overhead and holes that were stars •Believed, the blanket was kept up by a spinning “world pole” •Bottom of the pole was on a woman underground named Stone Ribs Tracking Cosmological Events
•Summer and winter solstice were very important for the first nations •Solstice comes from latin sol meaning sun and stice meaning stop •In north summer solstice is near June 21
oMarks the longest period of daylight in the year and start of summer •Winter solstice is near December 21
oMarks the shortest period of daylight in the year and start of winter •Conditions are reversed in south
•Equinox was a phenomenon honoured by early cultures
•One occurs in spring march 21 and on in the fall September 22 •Word equinox comes from Latin equi meaning equal, and nox meaning night •Equinox, day and night are of equal length
•Mayans of centeral America built a ginormous cylinder-shaped tower at chichen itza to celebrate the occurrence of the two equinoxes
•Prediction of the approach of summer and winter was important to early peoples •Many ancient civilizations built huge monuments to honour their beliefs about change •Even though they had less technology, their observations of the postions and the path of the sun throughout the year were highly accurate •More than 3500 years ago
oA people (ancient celts) created the megaliths of Stonehenge oAre still standing in southern england
oArranged in concentric circles
oBig stones mark the summer and winter solstices
•Ancient African cultures also set large rock pillars into pattern that could predict the timing of the solstices
•Ancient Egyptians built many pyramids
•Also built other monuments to align with the seasonal position of certain stars •Entrance of Khufu, the great pyramid at Giza once lined up with Thuban (a star in the constellation of draco) •Time the pyramid was built, starting about 2700 B.C. thuban was the closest star showing true north •2000 years ago, natives of southwestern Alberta used large rocks to build medicine circles in which key rocks aligned with the bright stars that rose in the dawn •Stars such as Aldebaran, Rigel and Sirius
•First nations in southwestern Alberta used large rocks to build the circles in which aligned with the stars specifically at the time of dawn.
Important Events in the yearly cycle marked by these monuments: Solstice:
It comes from the latin word sol, which means the sun and stice which means stop. The sun stops at a certain point and stays there for the whole day. Summer solstice in the northern hemisphere is the longest day of the year and winter solstice is the shortest day. In the southern hemisphere the conditions are reversed. Dates: Summer- June 21 Winter-December 21
Equinox is when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator. The day and night are of equal length. Dates: Vernal Spring March 21 autumnal Fall September 22
What ideas about the sky’s organization were there?
Geocentric Model (of planetary motion):
Genocentric meaning the earth-centered model is when a greek philosopher (Aristotle) showed earth at the center surrounded by a series of concentric spheres. Those spheres represented the sun, moon, and the five planets known at that time. Why this belief was held:
To explain why the distant stars did not move, Aristile hypothesized that they were attached firmly to the outermost sphere. The sphere was called the celestial sphere where the stars stayed put.
Heliocentric Model (of planetary...