In message , dave
writes
How do you get the two halfs of a ping pong ball back together again after
prising them apart? This is a serious question - my kids want to know!

I think the best answer is that you don't. Even if you tried, you'd end
up with a bit of a naff, unbalanced sphere with no bounce

Aren't they made of some form of cellulose? - they burn well, that will
entertain them for a few minutes

You could always give them a golf ball to unravel, that would last a few
minutes more

--
geoff