Comment Re:What does that even mean? (Score 0) 506
If the matter within the universe is expanding, it has to be expanding into something. What is that something?
Here's my take on it.
"Outside" the universe is undefined in the same way as division by zero and Not A Number are undefined "values".
One could say it "expands" into the nothingness of non-existence however the whole idea of "expansion" and the resulting question of "into what?" is only an attribute of one particular way of describing a reference frame (a particular reference frame that comes naturally to us because we're inside looking outwards).
Let's change the reference frame:
freeze the "border" of the universe all the way from the big bang until today and towards whatever future and treat this "border" as a constant.
What does the changes within this fixed "border" look like?
A "singularity" (bending the word, hope you understand) which internally increases (so far at least) in differentiation and separation of non-nothingness and nothingness, internally.
Somewhat like a fractal like for example a Mandelbrot set, however a fractal which only moves "inwards" and which along the dimension of time changes from a point of even distribution into a point of infinite internal complexity in all dimensions as if it increased in existing complexity at the very same time as you zoom in on it.
Another description would be us looking out at things moving away and instead of thinking of those things as if they were expanding away we instead think of us as falling away from them into increased complexity. Those things are also falling into increased complexity however we're falling faster than those things closer to the "border" of the "singularity" and those things closer to the "center" of the "singularity" are falling faster than us thus giving us the illusion that we're falling faster than both (the distance to both groups increases at an accelerating pace as everything continues to fall faster).
Back to the "universal fractal". Just what would such a fractal look like?
I don't know but I know of a description that seems to catch the gist of it: it's turtles all the way down ^_^