Riemann’s post helps some. Thanks.
The cosmic microwave background radiation is radiation that was emitted by matter. In the very early Universe, there was a bunch of matter packed very tightly together. It was all ionized matter, which interacts very strongly with light. And it was very hot. So light was continually being produced by bits of matter, but then almost immediately getting re-absorbed by other bits of matter. Eventually, though, the Universe cooled off enough that protons and electrons could combine into neutral atoms. Neutral atoms are much more transparent to light than plasma is, and so once this happened, all the light which existed in the Universe (which was basically just like all the light that had existed previously) could now fly free willy-nilly for very great distances, instead of being almost immediately absorbed. That light which just barely escaped getting re-absorbed is what we see as the CMB.
And since the CMB was produced by the matter, it shows us patterns in how the matter was arranged.
I meant a millimeter to the right or to the left.
Let’s suppose there is a bomb designed to explode into a finite number of pieces. Ten pieces for example. And they will be dispersed randomly, to a distance of five meters from the explosion. So these ten pieces will land approximately as a circle with a circumference of 31 meters. So there will be (on average) 3 meters of empty space between nearby pieces. If I am standing on that circle, the odds of getting hit by a piece of the bomb is clearly less than 50%, because my width is much less than 3 meters.
If I did get hit by a piece of the the bomb, and this happened repeatedly, I might conclude that the pieces did not go in random directions, but that they went in a set pattern, and I was in the line of fire. However, if I would move to another part of the circle, and I got hit by a piece anyway, I would conclude that it explodes into a lot more than just ten pieces.
For example, if this circle’s circumference is 31 meters, and I moved to another spot 3 meters away, or 13 meters away, or 22 meters away, I might conclude that the bomb actually explodes into 31 pieces. How else can I explain the fact that I get hit every single time? And if my choice was to move to a spot 3 or 13 or 22 centimeters away, and I still got hit every single time, then I’d conclude that it must be exploding into 3100 pieces.
This is what I mean by “moving a millimeter away”: If I can see the quasar from any location, then it must be throwing its protons in every direction.
I think we can agree that the light of these objects is quite dim. I had always presumed that this dimness results from a lack of energy in the photons. But you seem to be saying that the photons themselves are intermittent: throw a photon now, but not now; here and there, but not the other place - it’s not a lack of energy, but a lack of quantity. The photons are actually fewer.
Could that really be the case? Could a telescope be looking directly at a distant body, and be unable to see it for a while (microseconds, whatever), NOT because of any limitations of technology, but simply because that distant body did not shine any photons towards us recently, and we merely need to wait?
A couple of thoughts.
Sound is just a compression wave. So, as noted, it has to have someting to propagate in. Sound can propagate in most matter, solid, liquid, gas, plasma. It gets just plain weird in superfluids.
So you can regard sound as a coherent propagating vibration (making up terms as I go here) in the medium.
Typically we talk of sound as eventually dissipating, and the energy turning into heat. Heat is just random (ie incoherent) vibration. The idea being that eventually the sound energy just joins the chorus of thermal noise.
It might do this for a lot of reasons. It might run out of medium to propagate in. The medium may be itself heterogenous, with different speeds of sound in different bits, and so distrurbing the shape of the propagating wave enough that eventually it is so incoherent it is just random noise (and thus indistinguishable from heat.)
Sound will reflect of a boundary, so if it reaches the end of the media, energy can reflect back. So the reflected wave can continue on and probably scramble more.
However a few interesting thoughts. If the amplitude of the sound is less than that of thermal motion, the sound is not gone. It just takes longer to fish it out of the noise. This is Shannon’s theorem. In a classical world, if you have enough time, you can fish an arbitrarily low amplitude signal out of the noise. (Even in a quantised world this is true, and is how we see ridiculously faint astronimical objects.) If you add more sensors for the sound (like measure the wave front at a lot of locations, or make your telescpope bigger) the signal to noise improves as well.
In the extreme, if you turn the arrow of time backwards, your sound wave will be reformed and propagate back to its source. You might lose it if you drop it into a black hole, but nobody really understands that bit.
So there is the philosophical question about the nature of the universe. In a deterministic universe, no state seems to ever be truely lost. Given the current state of everything, you can deduce the earlier state, and thus your sound wave never really went away.
As I tried to explain in my post above, no, this is incorrect. The fact that a telescope can detect the object does not mean there is at least 1 photon per 1 square millimeter “at a time” (whatever that means.)
GN-Z11 is extremely faint. To observe its spectrum and determine the distance to it, the Hubble Space Telescope - a 2.4 meter aperture telescope - had to spend 18 hours observing it, just to collect enough photons to build a spectrum (probably a few thousand photons total). They also used several hours of observing time at the Keck telescope (a 10-meter aperture telescope) to confirm the measurement. So the photon flux from this object is way less than the 1 photon / square millimeter that you seem to be assuming.
Absolutely. This is exactly what is happening.
Light is quantised. In a simplistic manner, choose a small enough time interval and a small enough sensor and there will be intervals where there are no photons detected. Or take a faint enough source, and no matter how large your sensor, you have to wait for a photon to arrive.
At the other extreme, the double slit experiment can be performed where there is only one photon in transit. (And thus, classically will only go through one slit.)
In a quantised world, Shannon’s theorem also holds. If you wait long enough you can haul a signal out of the noise.
But you can only see it “from any location” if you use a large enough telescope, and/or collect photons over a long period of time.
Yes, that is correct. If you point a telescope+detector at a very faint object, the detector will only detect a photon infrequently. It may take hours to collect just a few photons.
YES. And not just “microseconds” - it could be hours or days.
When observing a very faint object in the sky, it may take hours - or days - just to detect a few photons from that object. The Hubble Extreme Deep Field image was constructed from 2 million seconds (about 23 days) worth of observation. Which means some galaxies in that image are so faint that a 2.4-meter telescope (that’s 50 square feet area) would only receive one photon every few hours from that galaxy.
Wow. Ignorance has been fought! Thank you all very much.
Thank you for that clear explanation. I am still left wondering why there isn’t (or is there?) any remnant of that pattern in the matter at a very large scale.
Geez people, I ask a simple question and ^^this results? 
I do appreciate all your input, but could someone put it into little words that this laywoman might be able to comprehend?
Thank you for your kind consideration. 
In the beginning there was nothing, which exploded.
Well thank you Riemann, that explains everything. 
Except it doesn’t actually answer my question (in terms that don’t make my eyes glaze over).
There is. From the Wiki I linked to earlier:
Then read the following “Cosmic Sound” section for a more detailed explanation.
Oh right, you’re the OP!
Ok… very looooose analogy.
Assume that in some sense we’re in a totally “quiet” universe and just one sound is made. So the fading sound will never be drowned out by other small noises. To answer your question, even in this situation, the sound will not last forever.
Quantum mechanics says that the universe is fundamentally “pixellated” - the universe has a finite maximum resolution. Unlike camera pixellation, though, it’s not just a limit to what we have the technology to see - it’s a limit on the smallest size or the smallest bit of energy that can actually exist.
So, as sound waves lose energy, they eventually reach the limit of that pixellation. The tiny amount of energy that’s left won’t be recognizable as a wave any more, it will just disperse as a few pixels (of heat I guess?) in random directions.
Maybe somebody else can do better…
But that means the ‘sound’ still exists, even if it’s just a few pixels floating around the universe in isolated pixels? Have I understood this correctly? Obviously it wouldn’t be the sound that was originally generated (stomping dinos, whingeing footy players as per my OP) but still the sound remains??
No, sound is not particles with independent existence. Sound exists as waves within matter (e.g. air, water). All that’s left at the end is a few random fluctuations - a tiny bit of heat, effectively - unrecognizable as a wave.
Yeah, but quantisation does not really provide a minium resolution. There isn’t a minimum energy possible. There are minimum energies for some interchanges of energy, but there is nothing that says that there is a an absolute energy below which there is no further progress. Maybe if the wavelength exeeds the size of the universe (for some variant of the size of the universe) but that brings the time since the universe began as a component.
On a more basic level however there is a very important point ot be made. Quantisation does not result in a fundamental barrier to resolution. This is counter-intuitive, and often results in heated arguments (especialy in audiophile circles.) Astonishingly, Shannon’s theorem for communication in a noisy channel holds perfectly in a quantised medium, in exactly the same manner as it does in a continuous (sometime erroneously called an analog) medium. The key is noise.
If there is noise in the quantiser with an amplitude equivalent to half the minimum quantisation level (be it amplitude, temporal, or spatial) Shannon holds perfectly. You can resolve signals at levels below the quantisation floor just as if it was a continuous signal. What you have to do is sample more. In a simplistic multiple sampling, resolution goes up with the square roor of the sampling, so you get a doubling in resolution for every quadrupling of samples. If you sample 16 times, you will be able to resolve signals at a level of 1/4 the quantisation level. You can also pull interesting tricks by massaging the spectral energy of your noise, adding resolution in one spectral band at the expense of another (which is SOP in digital audio.) The increased sampling changes the available bandwidth, which is what gets us back to Shannon.
But to re-emphasie the key point. You must include noise in analysis of the system. Naive ideas of quantised systems forget that noise is intrinsic in the real universe. If you forget this, it doesn’t work.
So, how best to describe in physical terms what ultimately happens to a sound wave in a homogeneous infinite medium that’s not perturbed in any other way?
I know you’ve absorbed knowledge by now, and that what I’m going to repeat isn’t directly what you were confused about, but I want to iterate one earlier point. When you write “at some point this game gets silly” you’re arguing from incredulity. To really defend your idea you would have had to do the math and show that it doesn’t match our knowledge of the expected number of photons sent out from an object, and the number of photons observed from said object.
At some point it gets indistinguishable from thermal vibrations in the medium. Or, if you keep your medium at absolute zero … Well, you can’t. Even if that’s where you started, at some point the energy from the sound wave will have been distributed randomly among the particles in your medium.