If space has a closed geometry,what will happen to two initially parallel flashlight beams as they traverse billions of light-years of space?
A) They will remain parallel.
B) They will gradually diverge (move apart)to a maximum separation,and then gradually converge and cross.
C) They will gradually converge (move together)and eventually cross.
D) They will gradually diverge (move apart).

Question

Quizplus · Accepted Answer

In a closed geometry, the universe is finite and has a curved shape like a hypersphere. As the two flashlights beams travel billions of light-years, they will gradually converge due to the curvature of space and eventually cross. This is because light follows the curvature of space and travels along a geodesic, which is a curved path in the curved space.

If Space Has a Closed Geometry,what Will Happen to Two