How do we know that the Milky Way is shaped like a flat disk?
A. Most other galaxies are shaped like flat disks, therefore the Milky Way must be shaped like a flat disk.
B. It is possible to visually trace out its flat disk shape if the night sky is dark enough.
C. Distant stars appear to be dimmer than nearby stars.
D. (None of the above choices (A)-(C), as the Milky Way is not shaped like a flat disk.)
Answer:B
How do we know that the Milky Way is shaped like a flat disk?
A. Most other galaxies are shaped like flat disks, therefore the Milky Way must be shaped like a flat disk. B. It is possible to visually trace out its flat disk shape if the night sky is dark enough. C. Distant stars appear to be dimmer than nearby stars. D. (None of the above choices (A)-(C), as the Milky Way is not shaped like a flat disk.)