ABSTRACT
The term “physical contradiction” is common in TRIZ; it came from the original works of Genrich S. Altshuller [1]. A physical contradiction is neither more nor less scientific than the technical contradictions described in the previous chapter. Both contradictions can appear in any technique. The mutually exclusive requirements are demanded from the same subsystem (function, characteristic or property, parameter, etc.) of the technical system or technological process in the case of physical contradictions. That is why a physical contradiction represents the
point
problem in the so-called
key
subsystem (function, characteristic, etc.). Often it is easier to operate with the opposite characteristics instead of working with the mutually exclusive requirements or two unequal values of a parameter for this characteristic. For example, an electron emitter should have a needle-like shape to emit a large electrical current in field emission flat panel displays, but with such a shape the emitter cannot maintain the electrical load and burns down. We can formulate the physical contradiction as follows: The edge of an electron emitter should be thick in order not to burn down and should be sharp to emit a large electrical current. In this case, the key subsystem is the edge of an electron emitter and the opposite parameters are sharp vs. thick. Such mutually exclusive or opposite requirements are often labeled as “positive” and “negative” characteristics.
