P3.2.1-P3.2.2 - Discovering the Universe 1 & 2 Flashcards
What did people in Thailand used to think caused solar eclipses?
They thought a god called Rahu swallowed the Sun
What is a Solar eclipse?
Where the Moon passes between the Earth and Sun so that you cannot see it.
Thousands of years ago what did Indians think the Earth looked like?
A flat Earth supported on pillars
Why do scientists use models?
To help them to explain observations
To help them to make predictions.
What is meant by the geocentric model?
The idea that every object in space orbits the Earth (the Sun, planets etc.)
Who came up with the Geocentric model?
Greek astronmers:
Aristotle
Plato
The planets are held in their orbits by which force?
Gravity
Which scientist developed ideas that led to our current understanding of gravity?
Isaac Newton
Why did people like the idea of the geocentric model?
It explain why the Sun and Moon appeared to move.
It did not involve the Earth moving.
It explained why the stars appeared to move.
What is retrograde motion?
When the planets appear to move backwards for a part of their orbit.`
What could the geocentric model not explain very well?
Retrograde motion
Which model overtook the geocentric model as the newly accepted model of the solar system?
The heliocentric model.
Describe the heliocentric model
Where all of the planets in our solar system orbit the Sun
The Sun is in the middle
Who came up with the Heliocentric model of the solar system?
Nicolaus Copernicus
What did Galilieo discover that led to the acceptance of the helicentric model?
That Jupiter had moons orbiting it.
