What is it expanding into?..........
"What is it expanding into?.........."
My thoughts exactly!
Meaningless question! It's probably better expressed by saying that everything got farther away from everything else really fast.
I like an explanation Physicist posted a while back:
"The problem is that the expanding universe is typically visualized as something like a stretching rubber sheet, or a raisin-laden plum pudding expanding as it bakes. The problem is that these are physical objects that exist in--and take up--some region of space. Over time, these growing objects take up more space, leaving less space for other objects, and either displacing those objects or reaching the limits of the available space. Once the plum pudding fills the oven, there's a problem."The expansion of the universe isn't like that. The universe is not an object; it doesn't "take up space". It is space. As it grows, it doesn't mean that there is less space for objects; it means there is more space for objects. Nothing needs to be displaced to admit its expansion." --Physicist
What was it when it was the size of a marble?
IT? How about the one infinitesimal into the one infinite expanse, thereby creating the unlimited number of infinitesimalities it takes to fill that expanse. The children of infinite "male" and infinite "female", which are two "sides" of the same coin, from our perspective, now making a coin's edge.
However, the three are dynamic at an infinite rate as well as static, as well as all the "velocities" in-between... our Universe.
Very simplistic analogy, dealing with the domains part only, to help me express what I feel comfortable with.
I don't know but now I have an explanation for the wife and the doctor... "hey, it's not just me -- it's the entire UNIVERSE!" ;)
It doesn't need to be expanding into anything.
It's not an explosion in space, it is an explosion of more space. Imagine a checker board and all the pieces arranged in their starting positions. An explosion of space would be like adding squares to this checker board. None of the pieces move, but they all get farther apart.
The "Great Unknown" which I define as oblivion.
Literally nothing, no space, no place, no location. Nothing