I remember Carl Sagan talking about this in Cosmos. He hinted that if the Alexandria Library had survived, we may have Star Ships now heading out to the stars. He pointed out those ship would not have USA written on them, but something like Roman letters.

I really doubt the human race would have been mature enough to handle today’s technology 1000 years ago. We have a hard time with it now.

Which brings up an interesting point. If Alexandria had not been destroyed, none of us would probably be here. There would be people here, and maybe even a technology advanced society, but none of us would be here. Such a huge change in history that far back would most certainly erase this future.

So those of y’all working on a time machine, don’t go changing the past :)