Where are all the blueshifted galaxies?
SMRTR summary
Most galaxies appear redshifted because the Universe is expanding, stretching light wavelengths as they travel through space, with more distant galaxies showing greater redshifts. While nearby galaxies can be blueshifted due to local gravitational effects, beyond 300 million light-years all galaxies are redshifted because cosmic expansion dominates over gravitational motion.
SMRTR provides this summary for quick context. The original article belongs to Hacker News.
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