Chapter 2: The Science of Life in the Universe

Question 1

What is the name of the path that the sun takes?

Answer 1

Ecliptic.

Question 2

How do the planets generally move?

Answer 2

From west to east.

Question 3

Planets sometimes show what kind of motion?

Answer 3

Retrograde motion.

Question 4

From what direction do objects rise and set?

Answer 4

They rise in the east and set in the west.

Question 5

Who found out that the earth was spherical? When was it?

Answer 5

Aristotle. 350 BCE.

Question 6

Ancient scientists of the geocentric model referred to what as epicycles?

Answer 6

The double spinning motion that attempted to explain retrograde motion.

Question 7

What did Copernicus give to the field? (5)

Answer 7

1. He simplified the geocentric model. 2. Sun was at the center. 3. All planets orbit the sun. 4. Earth rotates. 5. Uniform circular motion.

Question 8

What is Kepler’s First Law?

Answer 8

The orbits of the planets are ellipses with the sun at one focus.

Question 9

What is Kepler’s Second Law?

Answer 9

The straight line between the sun and a planet sweeps out equal areas in equal times.

Question 10

What is Kepler’s Third Law?

Answer 10

The square of a planet’s orbital period P (measured in years) is equal to the cube of the semi-major axis A of its orbit (measured in AU). P(^2)=A(^3).

Question 11

What is an orbital period? What is it for Earth.

Answer 11

The duration of one orbit (e.g. one year for Earth).

Question 12

What does 1 AU mean?

Answer 12

1 astronomical unit.

Question 13

What does 1 AU designate?

Answer 13

The distance from the Sun to the Earth.

Question 14

What did Galileo do for the field?

Answer 14

1. Invented the astronomical telescope. 2. First to use it to look at the sky and publish about it. 3. Breakthrough technology leads to new data revolution.

Question 15

Who essentially disproved the geocentric model?

Answer 15

Galileo.

Question 16

What else did Galileo discover? (2)

Answer 16

1. Phases of Venus. 2. Tied to angular size and position relative to the sun.

Question 17

How did Galileo essentially disprove the geocentric model? (2)

Answer 17

1. Venus tied to solar orbit. 2. We would never see illuminated side in geocentric model.

Question 18

Who solved the parallax problem?

Answer 18

Galileo.

Question 19

What is the solution to the parallax problem?

Answer 19

The stars are far away so the parallax must be tiny.

Question 20

Who came up with the heliocentric model?

Answer 20

Copernicus.

Question 21

What explains planet, moon, comet, asteroid, and stellar orbits?

Answer 21

Gravity.

Question 22

What two things did Einstein contribute to the field?

Answer 22

1. Gravity is woven into the fabric of space-time. 2. General relativity replaces Newtonian gravity.

Question 23

What explains apparent retrograde motion?

Answer 23

The planets do not actually change direction but appear to when they are passed by another planet closer to the sun (the planets closer to the sun move faster than those further away from the sun).