Chapter 1
The cosmic horizon of our sight
Chapter 2
The shape and geometry of space
Chapter 3
Is there an edge to everything
Chapter 4
The expanding cosmos and cosmic speed limits
Chapter 5
Three ultimate fates of the universe
YOUR GOAL
Master of Is the universe infinite
Ch 2 · The shape and geometry of space
artiteacher Shape of the universe
The cosmos stretches out flat! (Oh, so flat!) / Parallel lines never bend! (No, never bend!)
artiteacher The amount of matter and energy determines whether gravity will bend space.
artiteacher Scientists use giant triangles across the cosmos to test if space is curved.
Fun Fact
Cosmic flatness: The Planck satellite measured the universe's curvature and found it is flat to within a margin of error of just 1%.
Glossary
curvature (noun)
The degree to which a geometric object, such as a curve or a surface, deviates from being flat. In 2013, the Planck satellite analyzed cosmic microwave background radiation to measure the universe's overall curvature.
The degree to which a geometric object, such as a curve or a surface, deviates from being flat. In 2013, the Planck satellite analyzed cosmic microwave background radiation to measure the universe's overall curvature.
Quiz
Which space telescope provided the most precise measurements of cosmic flatness?
Quiz
What happens to parallel light beams traveling through a closed, spherical universe?
Quiz
If the universe is flat and infinite, how many stars could theoretically exist?