Arab world picked up a lot of the slack when europe went into the dark ages. China too. Just because us glorious caucasians weren't up to much didn't mean stuff stopped happening.
I wonder how much stumbling blocks hold us back like that though. China invented china (as in bone china) pretty early (hence the name). With a good way to hold their civilisation's juice discovered, they never really got on board with glass, didn't really need it. But then they kind of missed the boat on telescopes and microscopes and all that
