Eratosthenes' Measurement of Earth's Circumference

Play an AI-generated podcast conversation about this lesson

What is the Greek meaning of 'Planetes'?

Moving stars

Fixed stars

Shining stars

Wandering stars (correct)

What is the apparent yearly motion of stars and other celestial bodies across the sky due to Earth's revolution?

Monthly motion

Annual motion (correct)

Diurnal motion

Hourly motion

What is the collective name for the thirteen constellations?

Zodiac (correct)

Cosmos

Galaxy

Aurora

What occurs when the sun crosses the celestial equator?

Equinox (C) Signup and view all the answers

What happens to the Earth's axis during equinoxes?

It is tilted neither towards nor away from the sun (A) Signup and view all the answers

What occurs when the sun is at the farthest declination from the celestial equator?

Solstice (C) Signup and view all the answers

What was observed by ancient astronomers about the motion of planets?

The planets seem to move westward and then eastward. (A) Signup and view all the answers

What instrument did Tycho Brahe use to record the position of the sun, moon, and planets?

Giant protractors (D) Signup and view all the answers

What was Johannes Kepler able to derive from Tycho Brahe's data?

The orbital path of Mars is elliptical. (B) Signup and view all the answers

What is the shape of the orbits of all the planets according to Kepler's First Law?

Elliptical (A) Signup and view all the answers

What is the significance of the line joining a planet and the Sun according to Kepler's Second Law?

It sweeps out equal areas in space in equal intervals of time. (C) Signup and view all the answers

What is the relationship between a planet's orbital period and its semimajor axis?

The square of the orbital period is proportional to the cube of the semimajor axis (D) Signup and view all the answers

What was the reason Tycho Brahe was not able to develop a better model than Ptolemy's?

He did not have the ability to analyze his data. (D) Signup and view all the answers

What is the main difference between natural and violent motion according to Aristotle?

Natural motion is inherent, while violent motion is imposed (D) Signup and view all the answers

What is the term for the movement or change in location of an object over time?

Motion (B) Signup and view all the answers

What is the characteristic of a motion that is uniformly accelerated, according to Galileo?

Its speed increases by equal increments in equal times (D) Signup and view all the answers

What is the relationship between a planet's speed and its distance from the sun?

A planet moves fastest when it is nearest to the sun (B) Signup and view all the answers

What were the four elements that Aristotle considered as the proper places?

Earth, water, air, and fire (B) Signup and view all the answers

What is the main characteristic of horizontal motion?

It occurs in a straight line without any external force. (B) Signup and view all the answers

What was the approximate distance in kilometers that Eratosthenes estimated to be the Earth's circumference?

40,000 km (B) Signup and view all the answers

What was the primary reason behind the Greeks' preference for a spherical Earth?

Sense of symmetry (C) Signup and view all the answers

What was the main point of contention between Aristotle and Galileo regarding horizontal motion?

The need for external force to maintain motion. (C) Signup and view all the answers

What was the purpose of Galileo's experiment at the Leaning Tower of Pisa?

To show that the rate of fall is independent of an object's mass. (D) Signup and view all the answers

What was the central idea behind the geocentric model developed by 4th-century BC Greek philosophers?

The Sun, Moon, and planets orbit the Earth (B) Signup and view all the answers

According to Aristotle, what determines the rate of fall of an object?

The object's mass. (A) Signup and view all the answers

What is the primary function of a telescope in astronomy?

To see faraway objects (A) Signup and view all the answers

How did Eratosthenes calculate the Earth's circumference?

By measuring the distance between Syene and Alexandria (B) Signup and view all the answers

What was the limitation of Galileo's experiment at the Leaning Tower of Pisa?

The lack of a vacuum to test the hypothesis. (C) Signup and view all the answers

What is the main characteristic of free fall?

It is a type of motion where gravity is the only force acting on an object. (A) Signup and view all the answers