Anomalous Dispersion, Absorption and Kerr Effect in Viscous Dielectrics

The temperature variation of the dielectric constant and power factor of castor oil and rosin, measured at different frequencies from ${10}^7$ to 60 cycles, shows that, in accordance with Debye's theory of polar molecules, the region of anomalous dispersion of these very viscous liquids shifts with decreasing temperatures into the long-wave radio region and even down to audio frequencies. The measurements qualitatively verify the theory. The influence of viscosity in solutions of rosin in different oils which have no polar molecules is found in agreement with the theory. The existence of anomalous dispersion in the audio and radio frequency region explains the complicated dielectric behavior of many insulation materials and makes it possible to observe an anomalous behavior of the Kerr effect, or electric double refraction. According to Debye, this effect is due to the orientation of the molecules and should disappear at temperatures and frequencies where the orientation of the dipoles is impossible. We find, as is to be expected, that the regions of anomalous Kerr effect and of anomalous dispersion coincide.