Topic 7 (early Models Of The Solar System Flashcards
What is an example of ancient civilisations using solar and lunar cycles for agriculture
In ancient Egypt they would use the the time when the bright star Sirius rose after sunset to predict when the Nile would flood.
How did ancient civilisations use the moon and sun cycles for religious systems
Stone monuments and temples were built as ceremonial or religious observatories.
How did ancient civilisations use solar and lunar cycles for time and calendar systems
The ancient Egyptians used the cycles of the moon and sun to make a calendar with 365 days per year and 30 per month
How did ancient civilisations use the sun and moon systems for alignments of monuments
Ancient civilisations aligned their monuments to significant celestial objects such as Orion’s Belt or to the rising of the sun on specific dates ( ie the summer solstice)
Why are the monuments that were aligned with celestial objects now unaligned
This is because the earths axis of rotation is not fixed but traces a circular path against the stars. This relatively slow “wobbling” of the earth called PRECESSION arises from the pull of the moon and sun on the equatorial bulge; on complete axis rotation = 26,000yrs
What were the early models of the solar system and what do they mean
Geocentric solar system model - means that the earth is at the centre of it
Why was the geocentric model of the solar system flawed and what was changed to rectify it
It could not explain the planets retrograde motion and so epicycles on top of the planets orbit were introduced to explain it.
What did Ptolomey do to the solar systems model as a refinement
He moved the earth to be slightly of centred and created an imaginary point called the equant from which the angular motion of the centre of epicycle (P) was uniform.
This was to explain the variation in speed that the other planets exibhited
