❓ why
Why does the Universe’s expansion make distant galaxies redshift?
Quick Answer
As space itself expands, the wavelength of light traveling through it stretches, shifting it toward the red end of the spectrum.
The Full Story
Astronomers measure redshift when light from distant galaxies arrives with longer wavelengths than when it was emitted. This happens because the universe is expanding, so the space between objects stretches while the light is in transit. The idea was established in the early 20th century and became a key piece of evidence for an expanding universe. Edwin Hubble’s 1929 observations helped show that more distant galaxies generally have larger redshifts.
Key Facts
1.Edwin Hubble’s work was published in 1929
2.Redshift means light is stretched to longer wavelengths
3.Expansion of space causes the effect
YouTube Angle
Suggested video title for this topic:
"Why do distant galaxies look redder? Space is stretching their light."
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