Lesson 3

Question 1

What is considered to be the oldest science?

Answer 1

Astronomy

Question 2

What are the 7 days of the week named after?

Answer 2

Sun, Moon, Mars, Mercury, Jupiter, Venus and Saturn)

Question 3

How did people in Central Africa in 6500 BC use the sky to predict the seasons?

Answer 3

Due to the orientation of the crescent moon

Question 4

How did Greek philosophy spread?

Answer 4

Through Alexander the Great in (323 BC)

- his followers would found the library of Alexandria, the biggest site of ancient researchers

Question 5

Who preserved Greek philosophy?

Answer 5

The Muslims in Baghdad
- the fall of Constantinople in 1453 caused Eastern scholars to head to Europe, helping to ignite the European renaissance

Question 6

Where does the geocentric model place earth?

Answer 6

At the centre of the universe

Question 7

What properties did Plato claim the heavenly bodies should have?

Answer 7

They should be perfect, and thus their orbits should be perfect circles

Question 8

What did Ptolemy have to add to Plato’s model?

Answer 8

He explained retrograde motion, keeping a geocentrist view of the universe

Question 9

What did Copernicus suggest? Was he the first to do this?

Answer 9

He suggested a sun-centred model (however, he kept the idea of perfect circles)
- no, he was not (Aristarchus of Samos was the first one to propose this)

Question 10

What did Tycho Brahe contribute to our knowledge of astronomy?

Answer 10

He compiled the most accurate naked eye measurements, but he still could not observe stellar parallax
- he still thought earth was at the centre, but now suggested that other planets orbited the sun

Question 11

What did Johannes Kepler contribute to the field of astronomy?

Answer 11

He tried to match Tycho’s observations with circular orbits but he found an 8 arcminute discrepancy which led him to conclude that orbits were not perfect circles but rather were elipses

Question 12

What are foci?

Answer 12

Two points on either side of an elipse

Question 13

What is the origin?

Answer 13

The centre of the elipse

Question 14

What is the major axis?

Answer 14

It connects both foci

Question 15

What is the semimajor axis?

Answer 15

The distance from the origin to one focus

Question 16

What is the amount of squeezing of a circle referred to?

Answer 16

Eccentricity

i.e. how far a shape varies from a perfect circle where E=)

Question 17

What is the range of eccentricity?

Answer 17

From 0 (perfect circle) to 1 (straight line)

Question 18

What are Kepler’s three laws of planetary motion?

Answer 18

1. the orbit of each planet around the sun is an elipse with the sun at one focus
2. as a planet moves around its orbit it sweeps out equal areas in equal times (faster closer to the sun and slower the farther away it gets)
3. more distant planets orbit the sun at slower speeds, obeying the relationship P^2 (p=orbital period) OC a3 (= average distance from sun in AU)

Question 19

What does perihelion mean?

Answer 19

Close to the sun

Question 20

What does aphelion mean?

Answer 20

Far from the sun

Question 21

What were three rejections to the Copernican view?

Answer 21

1. Earth could not be moving because objects in the air would be left behind
2. heavens should be perfect therefore elipses can’t exist
3. we would be able to detect stellar parallax

Question 22

How did Galileo answer each refutal to the Copernican view?

Answer 22

1. Galileo showed that a moving object will stay in motion unless a force acts to slow it down
2. Galileo saw sunspots on the sun (imperfections) and mountains on the moon (like imperfect earth)
3. Galileo showed that stars must be much father than they thought

Question 23

What is science? Does all knowledge come from science?

Answer 23

Science = knowledge

- not all knowledge comes from science (ex. you can know your favourite band without a scientific theory for it)

Question 24

What was the final evidence that Galileo showed, proving that the earth was not at the centre of the universe?

Answer 24

1. discovered moons orbiting Jupiter (therefore not all object orbited the earth)
2. observation of venus’s phases proved that it orbits the sun, not the earth
3. in 1631, astronomers observed a transit of mercury across the sun’s face

Question 25

What are the three characteristics of science?

Answer 25

1. explanations of phenomena are based on natural causes (no supernatural forces considered)
2. creation of models and testing them to discover the simplest explanation that fits
3. the predictions must be testable

Question 26

What are the necessary requirements for a scientific theory?

Answer 26

they must

• explain a wide variety of observations with a few simple explanations
• be supported by much evidence
• not have failed any major tests of validity

Question 27

Is astrology accurate?

Answer 27

No; their predictions are no more accurate than by pure chance