re: Spinoff thread- OT Math/Science guys, most difficult problem you've solved?

Probably a fluids equation. I hate diff eq. That stacked on top of the experimental variables required to solve equation involving boundary and turbulent flow (I hate any equation that requires experimental variables as I cannot see where they came from and why they are what they are. You can only fit an equation to the results). Fluids taught me how to solve the problems they taught in the class. I am still not well versed on the subject.