👤 whose
Whose observations first showed that the Milky Way is just one galaxy among many?
Quick Answer
Edwin Hubble’s 1920s work on Andromeda and other nebulae showed that they are external galaxies. This proved the Milky Way is not the whole universe.
The Full Story
Edwin Hubble used Cepheid variables and other observations to determine that Andromeda lies far outside the Milky Way. Once that was established, other spiral nebulae were also understood as separate galaxies. This transformed the size of the known universe from a single galaxy to a vast population of galaxies. Hubble’s evidence ended the old “island universe” debate.
Key Facts
1.Mid-1920s breakthrough
2.Andromeda shown to be external
3.Ended the spiral nebula debate
YouTube Angle
Suggested video title for this topic:
"The observation that turned our galaxy into just one of many"
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