I can't see potato chips being popular where there's not land to grow potatoes in or where frying in lots of oil isn't easy or convenient.
One of the awesome things about being a writer is that I can research nearly anything - tea? Bubblegum? Ants? Neurology? Chocolate? Textile production? It doesn't matter. It's all productive work.
I read way, way more Andre Norton than could possibly have been healthy. It was a short hop from her to the rest of the library's science fictional and fantastic holdings.
I'd say my biggest influences are writers like Andre Norton and, particularly when it comes to the Radch, C.J. Cherryh.
The 'science' in 'science fiction' isn't just physics and engineering. It can also be linguistics, anthropology, and psychology.
The 'indistinguishable from magic' thing is highly dependent on where a viewer is looking from and not something intrinsic to any particular sort of tech.
