radiation leftover from the Big Bang....?

Question

How can the tell this is cosmic microwave background radiation leftover from the Big Bang, and
not radiation from distant galaxys?

Answer 1

There are clumps of galaxies. In some parts of the universe there are massive collections of galaxies, with trillions of stars. Our galaxy has fewer than half a trillion stars. Andromeda, our sister galaxy, is bigger and more massive than our galaxy. But there are galaxies that dwarf all those in our local group combined.

There are also vast voids in space--areas where there are no galaxies. Galaxies tend to be arranged sort of like soap bubbles. They cluster around the edges of vast empty spaces.

The cosmic background radiation, however, is largely uniform. Its temperature and density is the same between closely packed galaxies as it is in the great intergalactic voids. This indicates its origin is independent of that of the galaxies.

I started answering this before I saw the responses of Bones and Quantum. They both provided very good answers, pretty much covering anything I said.

Pishisau's response is typical of those whose personal beliefs lead them to deny reality. Notice how he offers no evidence to support his contention that the big bang model is wrong.

Sometimes you find folks who will offer evidence, but their evidence is generally pretty weak. I know one fellow who thinks the big bang cosmology is completely wrong because it contradicts his obvious misinterpretation of some ancient manuscript. That just isn't the basis for a sound science.

The Dalai Lama explains that if reality contradicts one's religious beliefs, it behooves one to examine their beliefs most carefully and critically, and perhaps to excise that which ultimately proves unecessary (or just flat wrong). Wise man.

Answer 2

because the microwave background is EVERYWHERE, galaxies are just little spots in the sky. scientists have mapped the entire sky and foud that the microwave background has a temperature of 2.3 degrees kelvin. just as big bang theory predicted. hope this helps!!!!!

Answer 3

Galaxies are point-sources of radio energy; the background radioation is just that - it comes from no apparent source.

Answer 4

Big bang is the most nonsense theory ever brought up. It just did not happen that way!