The Cosmological Redshift

• The Cosmological Redshift

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• 2. Though the Doppler effect can be used to calculate the velocities of the galaxies, it is not an explanation of why they are moving away from us.

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• 3. The cosmological redshift is a shift toward longer wavelengths that is due to the expansion of the universe, i.e., the expansion of space itself. It is the expanding space that lengthens (or redshifts) an already emitted wave.