Actually, the CMB affirmed the Big Bang scenario implied by Friedmann-Lemaître's solution to Einstein's field equations.
The CMB, discovered in 1965,
originally caused problems for the big bang theory at the time because the radiation fit the steady state theory. The Friedmann-Lemaitre was a precursor to today's big bang, but it wasn't widely accepted until Hubble's finding of an expanding universe. Even Einstein rejected Friedmann-Lemaitre originally and thought eternal universe.
"Success was achieved in a classic paper published in 1957, where they showed how the elements could be produced by a combination of fusion in the cores of massive stars (for the lighter ones), capture of free neutrons also in stellar cores, and reaction chains that proceed rapidly in supernova explosions, basically the modern theory that we have already discussed. In the meantime, it was realized that fusion in the Big Bang would not have extended above helium and lithium, so that this event could not have been responsible for the creation of the elements. The Steady State advocates' alternative of formation in stars and supernovae was the correct explanation."
Steady State vs. Big Bang
Interesting that Penzias-Wilson got the Nobel Prize for their discovery while Gamow got zilch.
The CMB showed there was a beginning and ended up backing the big bang theory through Hubble's discovery.
Sigh
You're conflating important distinctions, and as a result your understanding of things is wrong.
First things first. For some reason I referred to
ding as
dblack. Brainfart.
The discovery of the CMB was essentially the death knell for the Steady State theory. The Friedmann-Lemaitre solution is not a precursor to the Big Bang as such at all. The solution actually supported both the Big Bang
and Steady State theories. The solution gives a homogeneous, isotropic and expanding universe. The Friedmann-Lemaitre solution in and of itself does not give a cosmological beginning. That's why I used the term
implied. It implies a beginning only in terms of expansion. A beginning does not necessarily follow from the solution alone.
Lemaitre was the first to assert an expanding universe as predicated on
his independently derived solution and affirmed by
his calculi relative to the astronomical observations made by Vesto Slipher, not Hubble! Lemaitre was the first to posit "Hubble's" Law as well. Lemaitre published his discovery in 1927, Hubble, in 1929. Lemaitre was initially overlooked because his proof was first published in an obscure journal before being translated and republished in English in a journal with a wider audience. Once again:
However, like Friedmann's paper, Lemaître's "A homogeneous Universe of constant mass and growing radius accounting for the radial velocity of extragalactic nebulae" of 1927 was published in an obscure journal. It was translated into English in 1931 and republished by the Royal Astronomical Society, but in 1929 Edwin Hubble published his paper on the velocity-distance relation with a more precise constant for the rate of expansion: "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae". Notwithstanding, Hubble used virtually the same input data as that previously used by Lemaître, and, once again, Lemaître was the first to unequivocally attribute the pertinent astronomical observations to the expanding universe described by the field equations of general relativity!
Lemaître got his due in 1931 for connecting galactic recession directly to his astronomical calculations and the pertinent calculi of general relativity, and the velocity-distance relation is sometimes more properly referred to as Hubble-Lemaître's law in the literature. (Lemaître struck his estimation of the expansion rate from his translated paper in deference to Hubble's more accurate calculations.) The myth that Hubble was the first to discover that the universe is expanding persists because Hubble's 1929 calculi for the rate of expansion were more accurate and because his and Milton Humason's follow-up paper "The Velocity-Distance Relation among Extra-Galactic Nebulae" (1931) provided an even more decisively comprehensive observational foundation for an expanding universe, which put the matter beyond all reasonable doubt. What Einstein's relativity theories were to physics, Lemaître and Hubble's discovery was to cosmology—a seismic event. Finally, in this wise, physicists Howard Robertson and Arthur Walker working together but independently of Friedmann and Lemaître, derived a variant of Friedmann's solution in 1934. Hence, the classic solution of the Einstein field equations giving a dynamically homogeneous and isotropic universe is referred to as the Friedmann–Lemaître–Robertson–Walker (FLRW) space-time metric (or the standard model of modern cosmology). In the face of the findings of Hubble-Humason of 1931, Einstein finally accepted that the universe was expanding, of course, but rejected Lemaître's apparent beginning.
Also see:
Who really discovered Hubble’s Law?
Who Really Discovered The Expanding Universe?
Move over, Hubble: Discovery of expanding cosmos assigned to little-known Belgian astronomer-priest | Science | AAAS
Georges Lemaître - Wikipedia
Lemaitre went one step further and posited a beginning for the universe. As I wrote in the above, he posited what became known as the Big Bang theory, what he called "the hypothesis of the primæval atom", which he elaborated on in 1931:
https://www.nature.com/articles/127706b0. Friedmann-Lemaitre's solution giving an expanding universe was never rejected as such; it was merely not affirmed until Lemaitre and Hubble's astronomical observations and the calculi thereof! You're conflating the solution, which gives an expanding universe, with Lemaitre's theoretical extrapolation, which gives a cosmological beginning. They are not necessarily the same thing. With the falsification of the Steady State, we have the calculi of general relativity yielding a beginning to our spacetime at the very least. Hence, Friedmann-Lemaitre, insofar as it pertains to an expanding universe, was established no latter than 1931. It was Hubble-Humason more extensive proof of 1931 that finally convinced Einstein that the Friedmann-Lemaitre solution was correct and caused him to remark that his cosmological constant was the greatest blunder of his career. It was Lemaitre's theoretical extrapolation—Lemaitre's cosmogony of a beginning via the primæval atom!—that Einstein rejected, not the Friedmann-Lemaitre solution of an expanding universe. Yes. Einstein held to an eternal universe believing that this would eventually be shown quantum mechanically. Einstein rejected both the Big Bang and the Steady State theories. He was averse to a beginning on one hand, and regarded the calculi of a steady state to be contrived.
The CMB
did not undermine the Big Bang scenario in any way, shape or form
"because the radiation fit the steady state theory" as you claim! You're conflating things again. On the contrary, the CMB affirmed the final state of the Big Bang epoch of cosmological development (approximately 380.000 years after the exponential expansion epoch). Indeed, the Big Bang theory predicted the discovery of the CMB; the Steady State theory did not! Here you're conflating the proof worked out by steady state theorists regarding the stellar nucleosynthesis of heavy elements with the CMB itself. All this proof did was improve our understanding of the Big Bang scenario. It was soon shown that it supported the Big Bang, not a steady state. All the proof actually showed was that Gamow-Alpher's notion that the heavy elements were synthesized at the beginning of the Big Bang epoch was wrong. This could not occur until after the end of the Big Bang epoch, not until after the universe had cooled enough for the mostly plasma state of matter to clump and form stars. Gamow-Alpher correctly predicted the discovery of the CMB, but they were wrong about the order of things. As it turns out their error did not impinge on the veracity of the Big Bang scenario at all. Moreover, most scientists had already come to have grave doubts about the Steady State model once it was shown that bright radio quasars and galaxies were found only at large distances. This means they existed only in the distant past. This is precisely what the Big Bang predicted. The Steady State predicted they would be found everywhere, distributed throughout the universe. These astronomical observations were made
before the discovery of the CMB. Hence, the support for the Steady State theory had already seriously eroded in the light of the mounting evidence before the CMB was discovered. The CMB precisely reflects what the final state of the Big Bang epoch would look like.
You read things out of my post that refute your account and read things into your source that aren't there because of the conflations in you head. Look, the history of the development of the Big Band theory is complex, and that's not the end of the tale.