
Floating Point Fault
Many years ago while at University I heard of an interesting fault.
A physicist had run the same program a few days apart but had got different results. And had noticed.
Upon investigation it transpired that the floating point unit of the ICL mainframe was giving incorrect answeres in the 4th decimal place.
This was duly fixed. But I wondered at the time how many interesting discoveries in physics were actually undiscovered hardware failures.