We detect the slight anisotropy in the cosmic microwave background by making redshift measurements: Wavelengths coming from the direction of Aquarius are slightly longer and those from the direction of Leo are slightly shorter.This redshift is a:

Question

Quizplus · Accepted Answer

The redshift measured in this instance is caused by the Doppler effect (Doppler shift), where the wavelengths of light change due to the relative motion between the emitter and the observer. This effect occurs for all objects that move away or towards each other, including galaxies moving away from us due to the expansion of the universe. Gravitational redshift is caused by the distortion of space-time around massive objects, and cosmological redshift is caused by the expansion of the universe. While all three effects can cause redshift, in this specific context, the Doppler shift is the best explanation.

We Detect the Slight Anisotropy in the Cosmic Microwave Background