Reminds me of the speculation surrounding the existence of an "ether" that would permeate space and was the medium of transmission for electromagnetic waves. It was abandoned when relativity came along but now the concept is being rethought...is Dark Matter and/or Dark Energy the new ether?
Back in my college chemistry class, I became pretty good a dry labbing experiments. That had the dual benefits of allowing me to get the work turned in even if I didn't get into the lab that week, and of giving me a way to check my work when I did get into the lab.
Sometimes the experiment and the dry labbed value didn't quite match up. If that error was too large, the solution was to add in a fudge factor at an appropriate point in the calculations. I suspect that may essentially be what dark matter really is.