Topic 7 Flashcards
What did ancient civilisations use solar, lunar, and constellation movements for
Create calendars
How were solar/lunar cycles used to determine agricultural things
Best time to sow certain crops
-the flooding of the NIle also had agricultural significance
What did people think of the lunar/ solar cycles in the past
THey were seen as deities and worshipped
What effect has precession had on alignment of ancient monuments
THe oscillation of the Earth’s axial tilt of 26,000 years means many monuments are no longer aligned
Define precession
The oscillation of the Earth’s axial tilt of 26,000 years
What is geocentric theory
All planetary bodies and the SUN have an orbit centred around Earth
Why was geocentric theory widelt accepted
-People had little information on gravity and celestial motion
-Explain why celestial bodies move across the sky once a day
Why was Aristarchus’ ideas not widely accepted
He put forward the heliocentric model but there was no observational evidence to support him
What ideas did Ptolemy offer
Ptolemy offered the idea that all bodies orbit their own centre called a micro orbit or an epicycle
They then make a larger orbit around Earth called the deferent
What is an advantage of the Ptolemaic model
Makes up for inaccuracies solely in the geocentric model
-It also gives room for the retrograde motion of planets across the sky
What is 1AU
The distance between the Earth and the SUn
-It is a mean average
What is the term for when we are furthest from the SUn in orbit
aphelion
What is the term for when we are closest to the SUn in orbit
perihelion
What is the value of 1AU
150,000,000km
What is a lightyear
The distance that light may travel thrugh a vaccum in the period of one Earth year
