When I moved from physics to computers, I thought a fundamental difference is that in computers you can have a fundamentally deeper understanding of everything which happens in them - because you constructed them and could (at least in theory) observe every detail.
Well, today I heard a talk about 'Vertical Profiling', which means profiling of application behavior not only in the application level, but also the library, virtual machine, OS, hardware etc levels. And I understood in how many different places optimization (virtual machine, OS, hardware) is taking place, and how non-deterministic everything becomes by that. Performance characteristics (as function of time) become 'emergent phenomena' by that ... To understand what is going on when an application runs, needs now careful observation of various performance measures on the different levels and correlation between these - by special instrumentation points and experimentation.
Actually, I guess this makes it similar to physics now ...
Could that tell us something about physics and reality?