"But what if I want to learn about the physics that drive hardware performance? The materials science behind the next generation of wearable computing? Or what

"But what if I want to learn about the physics that drive hardware performance? The materials science behind the next generation of wearable computing? Or what about how to bring electronics manufacturing back to the United States? " 1 and 2 you can ascertain through intensive reading and finding the right courses (which could cost money) - you have to be a pretty good autodidact but if you are, they're certainly possible. If you're not, then college will probably be a preferable path for learning most things - even stuff that's easily digestible online. 3 certainly isn't locked in academia; whether you can 'obtain' the knowledge from the field either is the interesting question. I'd guess the best way would be to just fail fast/iterate and hope you get the key pieces quickly.