Question

The disk of the Milky Way galaxy is about 1.0 ✕ 10⁵ light-years (ly) in diameter. The distance from the center of the Milky Way to the center of the Andromeda galaxy is about 2.0 million ly.

(a)

Imagine a scale model where the two galaxies are represented by circular plates. If the plate representing the Milky Way has a diameter of 20 cm, what would be the distance between the centers of the two plates in meters?

______m

(b)

What if? The Milky Way and Andromeda galaxies are members of the Local Group, a cluster of more than 50 galaxies spread across a spherical volume with a diameter of 10 million light years. Imagine you could create a scale model of the Local Group with the Milky Way and represented as circular plates with diameters of 20 cm. What would be the diameter (in m) of your spherical scale model of the Local Group?

_______m

Answer 1