The understanding of matter, meaning the structure of the atom, I am assuming since it is Quanta to Quarks
OK, firstly the discovery of the electron and the way it works in cathode ray tubes allowed physicists to develop the Cathode Ray Oscilloscope which significantly altered a physicists ability to measure certain quantities eg voltage, sound and so on.
This is the sort of thing they are looking for.
Understanding of the electron and atom led to the development of solid state devices which led to computers which allowed physicists greater calculation power.