Science Research doesn't happen for its own sake. Every effort needs to be a part of the pipeline of demand and supply. Otherwise it's just a tune that you sing in the shower.
It's almost unthinkable the amount of technology and innovations we would have never gotten if this was actually true in practice. So many inventions happened because two people happen to be in the same place for no particular reason, or someone noticed something strange/interesting and started going down the rabbit-hole for curiosities sake, with demand/supply having absolutely zero bearing on that.
I got to be honest, it's slightly strange to see something like that stated here out of all places, where most of us dive into rabbit-holes for fun and no profit, all the time, and supply/demand is probably the least interesting part of the puzzle when it comes to understanding and solving problems.
Everyone is connected to financial strings like puppets. If you are doing research without financial connection, you must be very rich, having a personal lab, having lots of free time, or not having family duties and worldly goals. Those are rare people, just like how wealthy countries had more scientists in the past centuries.
In cold hard dates, though, Fourier was already using his series to solve heat transfer problems in 1822.
I don't agree with the bizarre idea that every bit of research should have a clear utility. I'm just being careful about dates. And I think FTs kind of were invented with a view towards solving differential equations for physics. Just not electrical ones.
But, more importantly, who dictates what needs to happen. If you so desire, you should absolutely sing a tune in the shower, write a poem for yourself, calculate an effect and throw the piece of paper away, write code and delete it. The satisfaction is in exercising your creative urges, learning a new skill, exploring your curiosity even if no one else sees it or uses it.
I have had the privilege of working with some of the best physicists on the planet. Every single one of them has exposed only part of their work to the world. The rest might not be remarkable in terms of novelty but was crucial to them. They had to do it irrespective of "impact" or "importance". The dead-ends weren't dead to them.
Philosophically, as far as I know, we all get one shot at living. If I can help it, I am going to only spend a fraction of my time choosing to be "part of the pipeline of demand and supply". The rest will be wanderings.
Transistor was 1947 but a lot of the basic science was from 1890's - 1920's.
Still transistors right - what did they ever do for us? (apologies to the monty python team)
Why?