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Cosmic Microwave Background Radiation

Physics · Class 12

The Cosmic Microwave Background (CMB) is relic electromagnetic radiation from the early universe observed today mainly at microwave wavelengths.

T_CMB ≈ 2.725 K
λ_max T = b
Important Properties: The early universe was hot enough for matter and radiation to interact strongly. As the universe ex
Formula / Key Relation: T_CMB ≈ 2.725 K For blackbody radiation: λ_max T = b where `b` is Wien's displacement con
CMB is one of the strongest observational relics of the hot early universe.

Free-body idea — Cosmic Microwave Background Radiation — original sketch for this lesson (not copied from a textbook).