DESIGN FOR A BRAIN 



6/3 



Given a system, the effective parameters are usually innumer- 

 able, so that a list is bounded only by the imagination of the 

 writer. Thus, parameters whose change might affect the be- 

 haviour of the same system of two variables are: 



( 1 ) the length of the pendulum (hitherto assumed constant), 



(2) the lateral velocity of the air (hitherto assumed to be con- 



stant at zero), 



(3) the viscosity of the surrounding medium (hitherto assumed 



constant), 



(4) the movement, if any, of the point of support, 



(5) the force of gravity, 



(6) the magnetic field in which it swings, 



(7) the elastic constant of the string of the pendulum, 



(8) its electrostatic charge, and the charges on bodies nearby ; 

 but the list has no end. 



Parameter and field 



6/3. The effect on a state-determined system of a change of 

 parameter-value will now be shown. Table 6/3/1 shows the 



Table 6/3/1. 



results of twenty-four primary operations applied to the two- 

 variable system mentioned above, x is the angular deviation 



72 



