The Earth is a Sphere
Blog or Wiki Address:
Subject
Matter:
Math
Grade
Level:
High School Geometry
Lesson Objective:
Complete the sentence below.
Learners will demonstrate understanding of the methods by which ancient mathematicians and natural philosophers proved that the earth was round.
Subject Matter Content Standard:
G.CO.9. Prove theorems about lines and angles. Theorems include: vertical angles are congruent; when a transversal crosses parallel lines, alternate interior angles are congruent and corresponding angles are congruent; points on a perpendicular bisector of a line segment are exactly those equidistant from the segment’s endpoints.
Technology Standard: NETS for
Students:
3.b. Locate, organize, analyze, evaluate, synthesize, and ethically use information from a variety of sources and media
Background:
It is a popular myth that when Columbus set forth to sail around the world, that he was fighting against a belief that the world was flat. But Western Culture has described the world as a sphere since the time of the ancient Greeks. In this scavenger hunt, we will learn how Greek Mathematicians and other Scholars were able to use their understanding of geometry and a bit of common sense to determine the shape of our planet.
Use the resources below to guide you on this scavenger hunt:
Student Research Questions:
Essential Question:
1. How did ancient Greeks know the world was round?
Subsidiary Questions:
2. How accurate was Eratosthenes's estimate of the world's circumference?
3. Eratosthenes's technique presumed that the earth was a sphere, but there are a number of other shapes that would have produced the same results, such as an ellipsoid, a torus, or a cylinder. What other evidence was available to him that suggested a spherical earth?
4. What did the advisers to King Ferdinand and Queen Isabella believe about the shape of the earth?
5. Why did they oppose Columbus's Voyage?
6. What evidence did the un-educated sailors who crewed Columbus's Ships have that the earth was round?
7. If they knew the earth was round, why did the crew threaten mutiny?
