They mostly test physics. Ever heard about the guys that measured the speed at wich penguins got rid of their shit? At first your like "Wtf's the point of all this?". Later, after you've put a little thought into it, you see that the interesting part is how the evolutionary process might have looked that finally led to their awezum shitting speeds.
TL:DR
There's more behind their testing than meets the eye.(I don't know if that saying even exists in english but you should get the picture of what I'm trying to explain.)