Question

question 8
1 pts
what observational evidence supports the fact that our universe is expanding?
detection of cosmic strings
discovery of quasars
evolution of galaxies with distance
redshifts of galaxies
discovery of black holes

Explanation:

The key observational evidence for the expanding universe is the redshift of galaxies. Edwin Hubble observed that light from distant galaxies is shifted toward longer (red) wavelengths, and this redshift increases with the galaxy's distance—consistent with galaxies moving away from us as the universe expands. Other options (cosmic strings, quasars, galaxy evolution, black holes) do not directly support universal expansion.

Answer:

Redshifts of Galaxies