Question

1. in 1543, ____ published on the revolution of the celestial spheres, which said the universe was ____.

a. copernicus, heliocentric
b. sir isaac newton, geocentric
c. galileo, orb shaped
d. rene descartes, shrinking

1. heliocentric means that ____________. it was an idea promoted by ____.

a. the earth rather than the sun is the center of the universe; copernicus
b. the sun rather the earth is the center of the universe; ptolemy
c. the earth rather than the sun is the center of the universe; ptolemy
d. the sun rather then the earth is the center of the universe; copernicus

Explanation:

Question 3

To solve this, we recall historical scientific contributions:

• Option a: Nicolaus Copernicus published "On the Revolution of the Celestial Spheres" in 1543, proposing the heliocentric (sun - centered) model.
• Option b: Sir Isaac Newton is known for laws of motion and gravity, not for this work, and geocentric (Earth - centered) was the old view, so this is wrong.
• Option c: Galileo supported Copernicus' ideas but didn't publish this work, and "orb shaped" is not the key idea here, so this is wrong.
• Option d: Rene Descartes worked in philosophy and mathematics, not on this astronomical model, so this is wrong.

We analyze the meaning of heliocentric and the associated scientist:

• Heliocentric means the sun is the center of the universe (not the Earth).
• Option a: Says Earth is the center, which is geocentric, so wrong.
• Option b: Ptolemy supported geocentric, not heliocentric, so wrong.
• Option c: Says Earth is the center (geocentric) and attributes to Ptolemy, both wrong.
• Option d: Correctly states heliocentric as sun - centered and attributes to Copernicus.

Answer:

a. Copernicus, heliocentric

Question 4