They explained it with an elasticated rubber mat example, if you stand in the middle of the mat and they have put some apples at random places on the mat and start pulling at the edges you remain at the same spot and the apples are getting away from you.
But the fact it will all turn black around us is still not really taking shape in my mind.
Got a new watch, divers watch it is, had to drown the bastard to get it!
What's it expanding into?
That's what blows my mind, if all the mass was in one "dot" before the big bang and the universe didn't exist, what did that dot exist within? And now it's expanding what is it expanding into? Is it a big box and the universe will hit the walls eventually? If so what is the box in? Another box?
It presumably has something to dowith there being no edge and it sort of wrpas back around on itself in a dimension we don't understand i.e. in the same way the earth is a globe and you can go roudn in any direction and get back to where you started if you go far enough in one direction in the universe will you get to the opposite side of the universe from which you were heading. James Webb telescope might give us more clues and it's successor in 30 years time might be able to go even further.