Which powerful instrument did Edwin Hubble utilize at the Mount Wilson Observatory to settle debates about spiral nebulae?
Answer
The 100-inch Hooker Telescope.
Edwin Hubble used the 100-inch Hooker Telescope, which was the world's most powerful instrument at that time, while working at the Mount Wilson Observatory to investigate the distant nebulae.

Related Questions
What was the prevailing scientific understanding of the universe at the start of the 20th century?Which powerful instrument did Edwin Hubble utilize at the Mount Wilson Observatory to settle debates about spiral nebulae?What specific type of star provided the key evidence necessary for calculating the immense distances to spiral nebulae?What crucial relationship concerning luminosity did Henrietta Leavitt establish regarding Cepheid variable stars?In which year did Edwin Hubble identify a Cepheid variable within the Andromeda Nebula (M31)?What phenomenon results when a light source is moving away from an observer, causing its spectrum to shift toward the red end?What direct, linear correlation did Hubble establish around 1929 regarding galactic distance and velocity?What is the mathematical constant represented by H0 in the formulation of Hubble's Law (v = H0 d)?According to the provided table, why did the Andromeda Galaxy (M31) show a blueshift rather than a redshift?What major theoretical concept was seeded by the realization that the universe was systematically expanding?