Can a caveman melt some sand in a woodfire? Yeh probably.
That glass will be worthless for any sort of technology. And by the time he can make better glass, he's all out of stuff to burn.
You don't get to do technological civilization twice. The first one uses up all the easy-to-use resources, and supposing there is anything left at all, it won't be usable without the technology that they won't have.
Europe got to use glass because it had plenty of forests to burn. Those are gone. They won't be coming back any time soon.
Can a caveman melt some sand in a woodfire? Yeh probably.
That glass will be worthless for any sort of technology. And by the time he can make better glass, he's all out of stuff to burn.
You don't get to do technological civilization twice. The first one uses up all the easy-to-use resources, and supposing there is anything left at all, it won't be usable without the technology that they won't have.
Europe got to use glass because it had plenty of forests to burn. Those are gone. They won't be coming back any time soon.