Russian version

THE PRINCIPLE OF NOT EXCEEDING
(the necessary condition of a system's workability)

Yevgeny B. Karasik
Copyright © 1986-2003 Yevgeny B. Karasik

Study of biographies and works of prominent engineers, designers, and inventors reveals that many of them invented their own specific approaches to problem solving. For example, the Soviet aircraft engine designer A. A. Mikulin expressed one of his design principles as follows: "Do not cope with harmful forces but prevent them !"

Unfortunately, not all inventors were able (or had time and interest) to formulate their principles of creativity. For example, the Nobel prize winner P. L. Kapitza never revealed his methods of solving problems. However, analysis of his inventions allows us to do this for him.

The essence of Kapitza's principle is pretty transparent and can be explained as follows:

  1. Work of any technical system results in its gradual (or otherwise) deterioration. When the deterioration exceeds some threshold, the system becomes not operational.
  2. Work of any system consists of working cycles. The system has to complete at least one cycle to be of any use.
  3. If system has time to deteriorate beyond the above threshold before it completes one working cycle, then it is good for nothing. A necessary condition for a system to be workable is that the duration of its working cycle has to be less than the time required to wear the system down.

Surprisingly enough, there are many failing technologies, which fail solely because of violating this principle of “not exceeding”. Usually, they are emerging technologies. Kapitza seemingly knew this typical reason of their failure and used to begin the work on making them workable by analyzing the relationship between the duration of the working cycle and the time required for a system to fail.

The first time this brought him a success back in 1916. In that year he found a way of manufacturing long quartz threads, a problem which nobody before him was able to solve.

Previously, quartz threads were manufactured as follows. Quartz got melted in a pot. After that one touched the surface of the liquid quartz with a piece of wood and then started to quickly move the piece away from the surface. Quartz stuck to the wood and, as a result, a thread of quartz connecting the wood to the surface of liquid quartz appeared. The thread grew as the piece moved farther from the pot. However, nobody could obtain threads longer than 1 meter, because thread had time to crystallize by then, and torn off.

Here Tcrystallization < Tcompleteing the work . Kapitza found a way to invert this relationship. He proposed to use an arrow instead of a piece of wood. After touching the surface of the liquid quartz, it was shot out from a bow and had time to fly more than 30 meters before the thread got crystallized.

In 1924 Kapitza succeeded in conducting physical experiments in very strong magnetic fields. Until then nobody was able to do so because creating very strong magnetic fields required very strong electrical currents in solenoids that generated magnetic field. However, wires of solenoids could not stand very strong currents and melted.

Here Tdestruction of electromagnet (melting) < Tcompleting experiment . Kapitza tried to make the technology workable by inverting the relationship. Initially, he tried to cool electromagnet. However, it turned out to be ineffective. Then he checked to see if experiments could be sped up. This turned out to be possible. As a result, he broke a new ground in experimental physics: conducting experiments in very strong and short living magnetic fields.

Speeding up experiments, did not solve all problems, however. When a generator of the strong electrical current worked, it vibrated. The vibration distorted the results of some experiments.

Here Kapitza again noticed that the vibration does not reach the site of experiment momentarily. It takes some time Tvibration to reach the site of experiment. Unfortunately, the following relationship held:

Tvibration to reach the site of experiment < Tcompleting experiment.

Kapitza did not resort to insulating the experimental area from vibration. True to his style, he instead found a way to invert the above relationship. He moved the experimental area far enough from the generator so that vibration reached it after experiment was over.

In the 1930s, Kapitza created the first machine to produce liquid helium. Nobody before him was able to do so for the following reasons. All previous machines for converting gases into liquids worked as follows. The piston went down and drew in a gas through valves into the cylinder. After that the piston went up and compressed the gas. Simultaneously, the cylinder was cooled. As a result, gas condensed into liquid, and then was pushed by the piston through other valves into a canister.

However, liquid helium is super-fluid. As soon as helium was converted into a liquid, it simply flew away from the cylinder through the gaps between the cylinder walls and the piston and evaporated before being pressed into the canister. The time required for a super-fluid to leave a vertically oriented cylinder was equal to  2h/g  , where h was the height of the cylinder and g was the free-fall acceleration due to gravity.

Here Kapitza again proposed to speed up the working cycle in order to finish the job before all liquid helium had time to escape from the cylinder.

The above analysis of Kapitza's inventions show that he always resorted to one and the same principle, which he neither ever spoke out nor wrote about. It is not clear if he realized it at all. It is also not clear if he was simply lucky that one and the same principle used to solve all the problems he ever faced, or he chose these problems simply because they could be solved by the principle that he mastered.

Anyway, we can extrapolate our findings and conjecture that any prominent engineer is prominent because he firstly invents a new principle of inventing. We can also conjecture that he tries to apply the newly invented principle to solving problems, which other people failed to solve.

These conjectures have an important implication for further development of TRIZ. Until now, it has been developed by analysis of random inventions from the “Bulletin of inventions”. In the view of the above facts and conjectures, it makes sense to start analyzing inventions by prominent inventors in search for undiscovered methods of creativity.