What is a cosmological redshift?
Quick Answer
Cosmological redshift is the stretching of light to longer wavelengths as the universe expands. It is one of the main ways astronomers measure distance in the cosmos.
The Full Story
As space expands, light traveling through the universe is stretched, shifting its wavelength toward the red end of the spectrum. This is called cosmological redshift and is a key observation supporting the expanding universe. The farther away a galaxy is, the greater its redshift generally is, a relationship first quantified through Edwin Hubble’s work in the 1920s. Redshift helps astronomers estimate distances, look back in time, and study the early universe. It is different from a simple Doppler effect, though the two are related in everyday terms.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Why distant galaxies look redder than they really are."
Was this answer helpful?
Tap a reaction — it helps us pick what to cover next.