Where did the cosmic microwave background (CMB)come from?

Question

Quizplus · Accepted Answer

The cosmic microwave background (CMB) is believed to have originated from the time when the universe was about 380,000 years old and electrons and nuclei combined for the first time to form neutral atoms. At this point, the universe became transparent to radiation and the photons that were previously scattered by free electrons were released and have been traveling through space ever since. These photons have redshifted to longer wavelengths over time and now appear as microwave radiation. Option A is incorrect as the first stars formed much later than when the CMB was released. Option B is incorrect as hydrogen in our galaxy doesn't emit radiation at the same wavelength as the CMB. Option C is incorrect as dust in our solar system can scatter light but not at the same wavelength as the CMB.

Where Did the Cosmic Microwave Background (CMB)come From