THE PARADOX OF CHOICE 



ina. It has recently been possible to construct thermocouples 

 from organic solids so that at least in certain "fused ring" 

 aromatic systems the predominant circulating charge carrier has 



400 600 800 1000 



TEMPERATURE IN DEGREES KELVIN 



1200 



Figure 3. Curve showing electrical effect (voltage) from heat 

 differences in an organic semiconductor derived from benzene-like 

 molecules. The curve indicates that positive "holes" are predomi- 

 nant in charge movements. 



been identified. It turns out to be positive in sign. A few 

 thousand of those migrating electrons which must have plagued 

 typesetters in the chemical formulas of hundreds of thousands 

 of published works in the past century may be retired. 



A further example of the superb results of continuity and 

 common meaning afforded even the most complex aspects of 

 physical science by physical theory appears in a matter involv- 



59 



