Physics Test 1 - Chapter 3 Flashcards

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Questions and Answers

How were constellations originally defined?

Constellations were originally defined based upon the shapes of stars.

How are constellations defined today?

They are now defined based upon groupings of stars.

How does the appearance of the sky change during the evening or during the year?

The appearance of the night sky changes so that the stars rotate around the polar star once every 2 hours.

How many hours changes the appearance of the sky on one day to match the sky at the same time of day a month later?

One twelfth a day, or two hours. Signup and view all the answers

What is the ecliptic?

The ecliptic is the location of the moon relative to the earth when it is eclipsed. Signup and view all the answers

How was the location of the ecliptic determined?

Locations are determined based upon observations of the moon. Signup and view all the answers

What is special about the signs of the Zodiac?

The Zodiac sign is determined by what constellation lies behind the sun during a given month. Signup and view all the answers

What aspect of planetary motion is hard to model?

Retrograde motion is hard to model. Signup and view all the answers

What ancient Greek mathematician developed an early model of planetary motion?

Pythagoras created an early model of planetary motion. Signup and view all the answers

What was Aristotle's view of the heavens like?

Aristotle viewed the heavens as the earth being the center of the solar system. Signup and view all the answers

What determined the order of the spheres according to Aristotle?

The order was based upon how fast it was for planets to travel the sky. Signup and view all the answers

How did Eratosthenes measure the circumference of the earth?

By measuring the distance between two cities and the angle of sunlight on the summer solstice. Signup and view all the answers

What contribution to early astronomy was made by Hipparchus?

Hipparchus made some of the first measurements of the solar system. Signup and view all the answers

Who used Hipparchus's data to make a model of the solar system?

Ptolemy used Hipparchus's results. Signup and view all the answers

Who developed the first 'workable' model of the solar system?

Ptolemy created the first 'workable' model of the solar system. Signup and view all the answers

Who was the first proponent of the heliocentric universe?

Copernicus was the first proponent of the heliocentric universe. Signup and view all the answers

Who was the modern day proponent of the heliocentric universe?

Galileo was the modern day proponent. Signup and view all the answers

Who won the 'Battle for the Heavens' in the hearts and minds of the common people?

Galileo won the 'Battle for the Heavens'. Signup and view all the answers

What three things made the heliocentric view seem unlikely?

<ol> <li>Went against common sense, 2) Aristotle's viewpoint was the strongest and most widely accepted, 3) No evidence of the parallax movement of the stars.</li> </ol> Signup and view all the answers

Why would we say that Ptolemy's model was both accurate and fundamentally incorrect?

It was correct regarding the positioning of the planets, but the sun is at the center of the solar system. Signup and view all the answers

How did Ptolemy's model account for retrograde motion?

Through an epicycle. Signup and view all the answers

Why was it ironic that Galileo was threatened with torture for disagreeing with Ptolemy's view?

The Church was following the beliefs of polytheism. Signup and view all the answers

What is the origin of the modern use of the word 'revolution'?

The origin would be Copernicus' book with the same name. Signup and view all the answers

Study Notes

Constellations and the Night Sky

Originally, constellations were defined by the shapes made by stars; now they refer to groupings of stars.
The night sky's appearance rotates around the polar star every 2 hours, with stars shifting one-twelfth of a day or two hours every month.

Ecliptic and Zodiac

The ecliptic is the moon's location relative to Earth during an eclipse, determined by moon observations.
Zodiac signs are dictated by which constellation is behind the sun during a particular month.

Planetary Motion

Retrograde motion, the westward movement of some planets relative to fixed stars, complicates modeling of planetary motion.
Pythagoras developed an early planetary motion model.

Historical Views of the Cosmos

Aristotle proposed a geocentric model, positioning Earth at the center with planets ordered by travel speed.
Eratosthenes calculated Earth's circumference using the distance between Alexandria and Syene along with solar angle measurements.
Hipparchus made early solar system measurements that Ptolemy later used to develop his model.

Heliocentric vs. Geocentric Models

Ptolemy's "workable" solar system model was geocentric but acknowledged accurate planetary positions.
Copernicus introduced the heliocentric model; Galileo championed it in modern times.
Galileo won public support for heliocentrism despite facing threats from the Church, which favored Aristotle's geocentric beliefs.

Challenges to Heliocentrism

Heliocentric views were initially dismissed due to:
- Conflicts with common sense.
- Strong acceptance of Aristotle’s geocentrism.
- Lack of observable parallax movement of stars.

Ptolemy's Model

Ptolemy’s model incorporated retrograde motion through the concept of epicycles, where planets would loop in their orbits.

Cultural and Linguistic Impact

Galileo's conflict with Ptolemy was ironic due to the Church's adherence to polytheistic beliefs.
The term "revolution" in its modern sense originates from Copernicus' work, reflecting radical ideas about planetary revolutions around the sun.

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Description

Test your knowledge on constellations and the changing appearance of the night sky in this Chapter 3 flashcard quiz. Understand how constellations were defined historically and how they are classified today. Explore the phenomenon of stars rotating around the polar star throughout the night and year.