[yor_on]

Thanks for looking it up Zero, so it wasn't just me imagining it. One never knows when senility may hit, every day becoming a first one. Driving by the seat of my pants as it might be seen :)

And yes JohnPi. that's how some theorists imagine it. As a sort of 'dimensional circle'. You can also use time for it, as time dilation should make any recognition of a 'origin' very questionable if one now expect oneself to return, well, depending on scale and lifespans etc.

but it doesn't answer what's 'outside it', and introducing that question will lead you to an even bigger headache than a 'infinite universe'.

[yor_on]

It could be that the answer to those two is the same. There is nothing outside it and the universe is infinite, as far as we are concerned.