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Electromagnetic phenomena are sometimes associated with seismic events, but earthquake prediction using seismic electric signals (SES) has not been seriously considered since the early 1990s. There are several causes: (1) false alarms that have created panics in Greece, and (2) a strong critique of the Varotsos-Alexopoulos-Nomicos (VAN) method used there. An updated VAN method that includes time series analysis has made successful medium-range predictions, and short-range predictions when coupled with seismic time series analysis. Four types of potential mechanisms to create precursory SES relying on deformation effects, temperature effects, ore-mineral movement or groundwater variation are reviewed. Data relevant to each are insufficient to favor a single mechanism. Records of the number of false positive and missed events for an updated VAN method have not been well maintained. False positives appear to be abundant and render the method unusable. Co-seismic groundwater fluctuations are addressed, and two novel hypotheses of earthquake trigger mechanism are also presented: ionospherically induced electric (and resultant magnetic) fields to weaken rock thereby causing failure; and volatiles liberated from minerals additionally promoting rock failure. Recommendations for further study are included.

The article reviews the current literature related to lightning and makes a case for using lightning as an alternative source of energy. Objections to using lightning as an alternative source of energy are listed. Current literature is reviewed and articles are suggested as useful for building a tower, or using rockets or lasers to target a strike, or for quantifying a lightning strike.

The relation between the potential r −β and the asymptotic behavior of the eigenvalues of the ordinary wave equation for space dimension N → ∞ is found. An analogous relation is discussed when the wave equation involves an iterated Laplacian. A criterion is given to determine when a potential should be considered singular, depending on the space dimension and the degree of iteration of the Laplacian. Finally, a modification is suggested for the approximation proposed by Witten which sensibly improves the results for the ground state energy of the hydrogen and helium atoms.

Electrons bound on the surface of solid hydrogen catalyze the ortho—para transition. Under certain conditions the energy of the o—p transition is greater than that binding the electron to the surface. As a result, the electron may be ejected from the surface by the transition that it has initiated. We have calculated the transition rate for the self-induced electron emission and determined the conditions under which it could be observed.

The structure factor of Na is calculated including two-phonon terms and the Debye-Waller factor. The result is compared with the one-phonon approximation usually employed to evaluate the electronic transport coefficients. This multiphonon contribution can amount to 13 per cent at the melting point and 10 per cent at room temperature in the transport sensitive region of wave vector 1.5 k F q k F , where k F is the Fermi wave vector. We conclude that calculations of electronic transport coefficients of metals intended to attain a precision better than 10 per cent above the Debye temperature must take into account the contributions of the Debye-Waller factor and the two phonon terms.

The fluorescence spectrum of Cr 3+ in the antiferromagnet GdAlO 3 consists of four broad bands whose peak energies are not perfectly equidistant. A theory recently proposed for the splittung of the fluorescence of a magnetic impurity in a magnetic matrix accounts for the small asymmetry observed.

Electron scattering leads to corrections in the dielectric function of an electron gas and thus of the plasma frequency. These corrections are expressed in terms of the pseudopotential and the structure factor of the scatterers. The shift in the plasma frequency can be of either sign. In Ni the parameters that enter into the calculation are uncertain; scattering may, however, account for the observed shift with temperature of around 1 eV.

It is shown that the critical resistivity of antiferromagnets has a magnetic energy-like behavior, both above and below the critical temperature, Tc.

Results of optical absorption and conductivity measurements on hydrogen doped MoO 3 are reported. A simple band model based on ligand-field theory is used to assign the optical transitions and explain the origin of the activation energy obtained from the conductivity data.

It is known that a paramagnetic surface sheet persists far below the Curie temperature in the ferromagnetic semiconductors EuO and EuS. We show that the observed spin-polarization of the photo- and field-emitted electrons is largely determined by spin-exchange collisions in the surface sheet. A single paramagnetic atomic layer may have a depolarizing effect of up to 50 per cent. Other circumstances in which the proposed model might apply are suggested.

The nearly-free-electron part of the dielectric constant of liquid Cu, Ag and Au are calculated and the results are compared with available experimental data. The formulae are generalized for the case of liquid alloys.