A little insight into the grandest of the fundamental sciences: physics.
The physicist’s condition is one of constant optimism. To solve any problem, we have to imagine the best possible scenario, and then simplify it.
This morning, for instance, I’ve been revising how to derive the 3-dimensional acoustic wave equation. I’ve completed the proof and derived an equation for the intensity of the sound, with these caveats:
1. The sound wave in question must be a plane wave.
2. The wave cannot lose any energy as it travels.
3. The wave cannot become more dispersed.
4. The equation only considers one direction of travel (along the x-axis!).
5. The equation does not work for loud sounds (i.e. large wave fluctuations like those given out by a super-sonic jet, or perhaps by your mom, when she yells at you to come in for dinner).
Obviously, more complicated equations exist, and computers solve many equations that would be difficult to solve on paper. But at this level, physics is a blue sky science, all about ideal conditions.
Unfortunately, the real world’s more complicated, and I have to get back to work! Next revision stop: room acoustics.