Users create this software themselves and often overlook how important it is. In some types of embedded systems, the application software and the operating system software may be indistinguishable to the user, as in the case of software used to control a VCR, DVD player or Microwave Oven.
You can jam milk through pretty small holes with force like that. Before homogenization, fat globules range in size from 1-10 microns (a micron = ~0.00004 inch). After, the size range is reduced to 0.2-2 microns.
During milk standardization milk fat is added to the skim milk. The densities of skim milk and milk fat are known. The density change upon addition of fat is used to monitor and control the fat content of the standardized milk e.g. 4.5 % fat.