What is the primary cause of redshift observed for the vast majority of very distant galaxies?

Answer

The stretching of spacetime as the universe expands

For distant objects, the primary cause is cosmological redshift, where the fabric of spacetime itself expands while the light wave travels across it, physically elongating the wave.

What is the primary cause of redshift observed for the vast majority of very distant galaxies?

#Videos

What Does Redshift Tell Us About Distant Galaxies? - Physics Frontier

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