What do astronomers suggest is the cause of the cosmic background radiation?

Answer 1

The cosmic background radiation (CBR) that permeates the entire universe is very well explained by the Big Bang as being all of the photons that are just now getting to us from the decoupling event between matter and radiation that occurred about 379,000 years after the Big Bang. Due to the fact that since that time the universe has expanded quite a bit with the same number of decoupled photons filling the space, their color-temperature has cooled quite a bit, now down to the microwave region of the electromagnetic spectrum, hence the term cosmic microwave background radiation. The temperature related to the CBR is now about 2.7K and will continue decreasing as the universe continues expanding.

Answer 2

cosmic microvawe background is an strong evidence for big bang. it's temprature is 2.27 kelvin. it is so homogenous in all the sky. therfore it comes from out of the solar system or our galaxy.

Answer 3

For a few hundred thousand years after the Big Bang, the particles within our Universe -- protons, electrons, and photons -- were so dense that no proton could combine with an electron before the two were blasted apart by a photon. The photon energy (a function of the wavelength) were too high for any combination to occur.

As space within our Universe expanded, so did the wavelength of each individual photon. The result was a downward trend in photon energy (longer wavelength = less energy).

Eventually, photon energies decreased to the point where individual photons were not energetic enough to blast protons from electrons. At that point, electrons joined with protons to form hydrogen and helium -- atoms existed for the first time. And the photons, no longer able to blast apart the two when they collided with any such pair, just drifted off into space.

Since these two events -- the formation of atoms and the release of photons -- occurred everywhere in our Universe at the same time, these photons will be travelling with equal intensity in all directions from and to all points in our Universe. Thus, any spot in our Universe -- including our own planet -- will always be receiving these photons from every direction with (pretty much) equal intensity.

As these photons continued to travel through expanding space, their wavelengths continued to grow. Since all of them were released into space at the same time (about 377,000 years after the Big Bang), they will all experience an identical amount of wavelength increase.

In 1948, George Gamow -- and advocate of the Big Bang -- predicted the existence of such photons, coming to our Earth as isotropic microwave radiation. In 1964, these microwaves were discovered, and were found to be pretty much exactly as predicted by the Big Bang.

Answer 4

Astronomers believe the cosmic background radiation is the resultant left over (remaining) energy emitted from the Big Bang. As such, the background radiation would have been emitted at the moment the Big Bang occured.

The Cosmic Microwave Background, or CMB, is a nearly-isotropic 2.725 K signal which formed during the epoch of recombination (when the universe went from being mostly ionized to mostly neutral) approximately 300,000 years after the big bang (which itself happened about 13.7 billion years ago).

Answer 5

a long time ago in a galaxy far far away