I have my own theory where space does not have an ending or a beginning and it would be infinite. This has to do with a kind of bagel or donut theory where the universe expands in a circle until it loops around upon itself and where light photons bend around the circular universe creating a 3D projection of the universe we think we know however time actually lapses on itself and matter is held within this "donut" by the vacuum of space. what is outside of this donut I have no idea perhaps a vast matter less vacuum of inter-universal space.(not proven just another theory!!)