(E) Topic 3 & 4 Flashcards
When do particularly high and low spring tides occur?
At full and new moon
When do neap tides occur?
- Close to when the moon is half full
- When the Sun’s and moon’s tidal forces act at right angles to eachother
Evidence of Axial Precession?
- The changing ‘pole star’
- The misalignment of ancient monuments and temples
- The changing locations of the equinoxes
What is the rate of precession?
1.4 degrees per century
Explain how the gradual precession of the Earth’s axis is used in archaeoastronomy
The misalignment of ancient monuments and temples
Knowing the rate of precession of the earth’s axis, archaeoastronomers can determine the approx date of their construction
Whats the angular diameter of the moon and sun?
Roughly 0.5 degrees
Which 2 people were responsible for the ‘ cosmic distance ladder’?
Eratosthenes and Aristarchus
Who measured the diameter of the earth?
Eratosthenes
Who measured the diameter & distance to the moon?
Aristarchus
Who measured the distance to the sun?
Aristarchus
Whilst observing a lunar eclipse, what did Aristarchus determine?
- A lunar eclipse was produced (when moon passed through Earth’s umbra)
- Sun = very far away. Rays were parallel when reaching Earth
- Centre of Earths umbra = diameter of Earth. Moons path took it through this
What equation did Aristarchus use to present his 3 assumptions?
diameter of moon U1 to U2
————————- =
diameter of Earth U2 to U4