Expert: Jayendra Upadhye - 9/24/2007

Question
Hi,

I've seen the photos of the uneven distribution in the early universe and that this unevenness is what determined distribution of galaxies and empty spaces in the universse as we now observe it.

But what I am not clear on is this: Does the pattern of the photos map the current pattern of galaxies, etc? In other words, if we, metaphorically-speaking, shined a searchlight through a transparent sheet with the early-universe photo on it against a wall billions of light years away, would the picture on the wall show the distribution of galaxies as we now see it? Do we know this by matching the early photo with the current distribution of do we just *assume* that one led to the other?

Many thanks,

Steve

Answer
Steve,
The fluctuation is at the 3rd decimal level! In fact the CMB is so uniform at first sight as to be called isotropic!
(same in all directions)!

Sure i cant remember where i read about that decimal part, but i dont file away the "when" & "where"s, but the actual content of what a read at any time.

In this case, we have to go by "one led to another".
The initial small nonuniformities in the spread of matter were amplified millionfold by grvaity over the eons.

Plus the non-uniformity was not static (one small void remaining same over time and in relation to another void close by), as the first supernovas started to send schock waves into the more closely packed matter of the early universe.

Back then a supernova ended up "disturbing" much more matter, than an average super nova does now, as these days, the space is mostly vacuum! matter having got concentrated in thin filaments spanning vast voids! (large scale structure of the universe).

It was a case of small non uniformities getting amplified by gravity, and a simultaneous "turbulent" mixing by the intermittent supernovas, that must have had a much higher formation rate back then than now.

The supernovas must have gotten started even before the galaxies had formed, sometime in the "dark age" of the universe, immediately after the bang, and the decoupling of matter and energy.

(But that as usual is my surmise based on "plain logic" if you will grant poor me, a pet theory of my own!)

jayen