My revelation wasn't that it was difficult or easy-- it was that unknowns lurk, in vast numbers, in places you don't even know exist, let alone don't know to lo

My revelation wasn't that it was difficult or easy-- it was that unknowns lurk, in vast numbers, in places you don't even know exist, let alone don't know to look. It sounds easy, with hindsight, to say "Of course the burn profile of the fuel grain would determine the the thrust curve". The idea of fuel grain burn profile just simply hadn't occurred to me. Sure-- I knew motors had total and specific impulse but, I grew up on Estes motors as "black boxes" and never thought about motor manufacture or that performance could be engineered. I never thought about the motor as anything more than "put an ignition source in, get energy out". I know I've had a lot more of these moments. This was just a memory evoked by the parent post. I'm having trouble coming up with another of these "deep holes that look shallow, or don't even look like a hole at all" moments immediately to relate a second anecdote. These shallow-looking deep holes clearly exist in large numbers. By their very nature we can't know how many there are. They're fractal, too. Inside each one are more similarly-appearing (or not appearing) holes to go down. That idea might trouble some people, but it's very exciting to me. The only troubling bit is knowing I have a finite period explore the space of knowledge and a limited capacity to understand. That doesn't discourage me, though.