Chapter 3 Quiz Jessica Brandon

Astronomy Quiz #2

1.    How did Copernicus, Tycho, and Kepler challenge the Earth centered model?

Copernicus used the model to determine the layout of the solar system planetary distance in AU. The model was no more accurate than the Ptolemaic model in predicting planetary position because it still used perfect circles.

Tycho he compiled the most accurate naked eye measurement ever made of planetary position. He still could not detect stellar parallax and thus still thought earth must be the center of the solar system but recognized that other planets go around the sun he then hired kepler.

Keples first tried to match tychos observation with circular orbits, but an 8-arcmintue discrepancy led him eventually to ellipses

2.    What are Kepler's three laws of planetary motion?

First law: the orbit of each planet around the sun is an ellipse with the sun at one focus

Second law: as a planet moves around it orbit it sweeps out equal times

This means that a planet travels faster when it is nearer to the sun and slower when it is farther from the sun.

Third law: more distant planets orbit the sum at slower average speeds obeying the relationship

3.    How did Galileo solidify the Copernican revolution?

overcame major objections to Copernican view. Three key objections rooted in Aristotelian view were: 1. Earth could not be moving because objects in air would be left behind. 2. Non-circular orbits are not “perfect” as heavens should be. 3. If Earth were really orbiting Sun, we’d detect stellar parallax.

4.    How can we distinguish science from nonscience?

Not all knowledge comes from science. The idealized scientific method based on proposing and testing hypotheses. Hypothesis= educated guess

But science rarely proceeds in this idealized way for example...

Sometimes we start by just looking then coming up with possible explanation

Sometimes we follow our intuition rather than a particular line of evidence.

5.    What is a scientific theory?

The word theory has a different meaning in science than in everyday life. In

science a theory is NOT the same as a hypothesis. The scientific method must

explain a wide variety of observation with a simple principles that is

supported by a large compelling body of evidence

6.    What does the universe look like from Earth?

With the naked eye, we can see more than 2,000 stars as well as the milky-way, a faint band of lights encircling the celestial sphere which is the sky.

7.    Why was planetary motion so hard to explain?

Planets usually move slightly eastward from night to night relative to the stars, but sometimes they go westward relative to the stars for a few weeks. We see apparent retrograde motion when we pass by a planet in its orbit.

8.    Why did the ancient Greeks reject the real explanation for planetary motion?

Most Greeks concluded that earth must be stationary, because they thought the stars could not be so far away as to make parllax undetectable.

9.    In what ways do all humans use scientific thinking?

Scientific thinking involves the same type of trial and error thinking that we use in our everyday live, but in carefully organized way.

10. How did astronomical observations benefit ancient societies?

Keeping track of time and seasons. For practical purposes, including agriculture. For religious and ceremonial purposes.