What is the fundamental observation supporting the idea that the universe is expanding when observing deep space?
Answer
Galaxies are overwhelmingly redshifted
The fact that the overwhelming observation across vast intergalactic distances is redshift provides the fundamental evidence supporting the expansion of the universe.
Related Questions
What phenomenon occurs when a light source moving away from an observer causes the light waves to stretch?What primarily causes the redshift observed in very distant galaxies across vast intergalactic distances?If a cosmic object exhibits a blueshift, what does that indicate about its motion relative to us?Which large neighboring galaxy is known to exhibit a measurable blueshift toward the Milky Way due to gravitational attraction?What is the fundamental observation supporting the idea that the universe is expanding when observing deep space?What cosmic signatures act as 'cosmic rulers' for comparing detected light wavelengths against stationary expectations?On what scale does local gravity typically become the primary driver dictating motion, sometimes causing blueshifts despite cosmic expansion?According to Hubble’s Law, what is generally evidenced by a greater redshift value observed in a distant galaxy?Do the existence of nearby blueshifted galaxies invalidate the model of an expanding universe?How does the redshift of a galaxy observed from the early universe (looked at very far back in time) compare to nearby galaxies?