Question

the two hypotheses that could explain why the Earth has seasons (winter, spring, summer, and autumn). For each of these two hypotheses, give two possible observational tests that can be performed from the surface of the Earth that would serve to support or refute the hypothesis. Be as specific as possible about the prediction made and what would be observed. (An example of a specific, although incorrect, prediction might be: “If you were in Boston and faced north, you would see the Sun rise directly in front of you at 6:00 every morning throughout the year.”)

If you know what the outcome would be of the observational test, state this outcome and whether it would support or refute the hypothesis. This is not necessary, however. Your answer should contain 4 observational tests, two for each of the two hypotheses. However, a similar test can be proposed for both hypotheses if the outcome of the test is predicted to be different

Observed: From Boston, there are 4 seasons: winter (cold), summer (hot), fall, and spring (intermediate). Note that this is given, so that measuring temperatures is therefore not a legitimate test!

Hypothesis 1: The Earth revolves around the Sun in a nearly circular orbit, so its distance from the Sun is nearly constant. However, the Earth’s spin axis (it spins once per day) is tilted with respect to the orbit and always points in the same direction (toward the star Polaris). This causes sunlight to shine more directly on the surface of the spherical Earth in summer and less directly in winter. The more intense sunlight in summer is the reason for the warmer temperatures during that season.

Hint) Hypothesis 1 for the Earth’s seasons. The spin axis of the Earth always points in the same direction and the Earth’s distance from the Sun is nearly constant. When the northern axis is tilted toward the Sun, the northern hemisphere experiences summer, and when it points away, it experiences winter.

Hypothesis 2: The Earth revolves around the Sun in an elongated elliptical orbit. This causes the Earth to be significantly closer to the Sun at some times than at others. Summer (hot season) occurs when the Earth is close to the Sun and winter (cold season) occurs when it is farther from the Sun in this elliptical orbit. [Note: In an elliptical orbit around the Sun, the Sun lies at one focus of the ellipse, not at the center, so that there is only one point in the orbit closest to the Sun and one point farthest from the Sun. See the sketch below and refer to Chapter 3 for a discussion of elliptical orbits.]

Hint) Hypothesis 2 for the Earth’s seasons. The Earth’s orbit is in the shape of an elongated ellipse. When the Earth is closest to the Sun, we experience summer, and when it farthest from the Sun, we experience winter

Answer 1

Hypothesis 1:

a) The role of the sun (as seen at a fixed place) on the identical time every day will show a direction in a round path over time.

b) Eccentricity =zero (or close to zero) means a circular movement. This method that the planet's velocity and distance from the Sun do now not trade at some point of the complete orbit. Thus, all seasons will have the identical duration.

Hypothesis 2:

a) The position of the sun (as visible at a set location) on the equal time each day will show a route in parent eight through the years (analemma).

b) An elliptical orbit (eccentricity >0.Five) method that the planet's speed varies across the orbit, faster as it gets near the solar and slower at the far aspect of the orbit.