The cosmic microwave background (CMB) is thought to be leftover radiation from the Big Bang, or the time when the universe began. It is called cosmic microwave background radiation. Currently it is commonly called the Cosmic Microwave Background or just CMB, alluding to its Wien peak in the microwave region. As the theory … The cosmic microwave background radiation is an emission of uniform, black body thermal energy coming from all parts of the sky. In cosmology, the cosmic microwave background radiation is a form of electromagnetic radiation discovered in 1965 that fills the entire universe. Mostly the cosmic microwave background The radiation from stars and galaxies is much weaker It was not always this way The early universe was radiation dominated density of radiation exceeded density of matter. CMBR is a second piece of evidence to show the expansion of space, and this supports the Big Bang model of the origin of the Universe. Cosmic Microwave Background Radiation The Big Bang Model is sometimes challenged in some of the same ways we see evolution being challenged. It shows the wavelength dependence of a "blackbody" radiator at about 3 Kelvins temperature. Cosmic microwave background (CMB), also called cosmic background radiation, electromagnetic radiation filling the universe that is a residual effect of the big bang 13.8 billion years ago. . Since astronomers provide evidence that the Universe is about 13.7 billion years old, those who believe in a young … "The cmB [cosmic microwave background] is the relic radiation from the 'moment' of first transparency, 4 × 10 5 years after the Big Bang, when the opaque plasma pervading the cosmos finally became cool enough (about 3000 K) to let neutral hydrogen survive. Cosmic background radiation is electromagnetic radiation from the Big Bang.The origin of this radiation depends on the region of the spectrum that is observed. 3K Background Radiation A uniform background radiation in the microwave region of the spectrum is observed in all directions in the sky. One component is the cosmic microwave background.This component is redshifted photons that have freely streamed from an epoch when the Universe became transparent for the first time to radiation. The Cosmic Microwave Background, or CMB, is radiation that fills the universe and can be detected in every direction. While this radiation is invisible using optical telescopes, radio telescopes are able to detect the faint signal (or glow) that is strongest in the microwave region of the radio spectrum. The radiation is isotropic to roughly one part in 100,000: the root mean square variations are only 18 µK, after subtracting out a dipole anisotropy from the Doppler shift of the background radiation. Because the expanding universe has cooled since this primordial explosion, the background radiation is in the microwave region of the electromagnetic spectrum. or CMBR.