  The permanent electric dipole moment (EDM) of the ground state of potassium
has been found by measuring the electric susceptibility. We find d(K)=(1.58
plus or minus 0.19(stat) plus or minus 0.13(syst)) times 10-8 e.cm and the
induced EDM, d(ind) is less than1.5 times 10-16 e.cm, can be neglected. The
experimental K material with purity 0.9995 is supplied by Strem Chemicals Co.
USA. This paper shows that the permanent EDM is based on the orbital angular
momentum (where the spin is irrelevant), and neither space inversion nor time
reversal is a symmetry operation for an alkali atom. In fact, the famous
Runge-Lenz vector M is simply the permanent EDM vector of an alkali atom. As
early as 1926, W. Pauli calculated the energy levels of the hydrogen using the
vector M. Therefore, our work may fall into the category of the most exciting
discoveries during the past few decades.
