What is the cosmic microwave background radiation?
a. A uniform background of radiation from electrons spiraling in weak intergalactic magnetic fields b. Radiation left over from the Big Bang after the universe expanded and cooled c. An almost-uniform background of radiation from distant, unresolved, overlapping galaxies d. Radiation from a very tenuous, ionized gas that fills the universe equally in all directions
Observing the spectrum of the cosmic microwave background radiation 1 billion years after Big Bang?
Suppose you could have observed the spectrum of the cosmic microwave background radiation 1 billion years after the Big Bang. How would the wavelength of radiation at the peak of that spectrum compare with the peak wavelength of today’s background spectrum? Explain your reasoning?
Is cosmic microwave background radiation the evidence of Big Bang?
It's not the only one, but it's an important one: if the universe today is filled with photons at a temperature of 2.7 K, then this means that the Universe must have been much hotter in the past, because the expansion cools it off. But when it was hotter in the past than this has big consequences for what happened then. For instance there must have been a time when the Universe was hotter than 3,000 K implying that *all* atoms where ionized. And a time when it was hotter then 10 million K meaning that hydrogen fusion took place. Here are a few examples of other supporting evidence, by which I mean predictions by the Big Bang theory that have been quantitatively verified. - The Universe as a whole is expanding as we see red shifts. - The observed abundance of hydrogen, helium and some other light elements produced just after the Big Bang confirms to prediction. - The large-scale structures observed in the universe today, are a consequence of small fluctuations shortly after the Big Bang - Einstein's Theory of Relativity, a theory for which there exist overwhelming evidence even from everyday phenomena, predicts an expanding Universe.
What is the source of the cosmic microwave background radiation?
theoretically, the background microwave radiation is a remnant of the "big bang" - it's presence is thought to indicate the residual energy from the universes' transition from singularity to it's expansion phase (where we are now, in part).