O ptimization, rock physics, and improved EM survey design compose the July-August 2015 Geophysics constellation of "Bright Spots." The diverse range of topics includes a tutorial on EM inversion methods, a new method for relating microseismicity to diffusivity in fluid injection, a new approach to deblending blended seismic data, a joint inversion of seismic and resistivity, a new seismic-dispersion analysis method, a rock-physics study of the effects on geophysical measurements of micrite in carbonates, a study of shear modulus determination in heavy oils, and a new EM transmitter-array design.Yin et al. present a "Review on airborne EM inverse theory and applications" as a tutorial on airborne EM (AEM) imaging and inversion methods. The following imaging methods are discussed: differential resistivity imaging, conductivity-depth imaging, and the EMFlow method, each of which is not an "inversion" in the sense of solving an inverse problem through some iterative technique, under some norm. The authors discuss 1D AEM inversion using the following methods: least-squares inversion, Occam's inversion, laterally constrained inversion, holistic inversion, Bayesian inversion, and simulated annealing as well as a short discussion of extensions of Zohdy's method, the S-inversion method, and a method by Sattel (2005), and an artificial neural net method of Zhu et al. (2012). The authors also discuss 2D and 3D AEM inversion methods assuming an isolated conductor. These include application of the Gauss-Newton method, the nonlinear conjugate gradient method, and quasi-Newton methods. The authors discuss a collection of methods created by the CSIRO group in Australia: the LeroiAir, ArjunAir, SamAir, and LokiAir algorithms. Finally, the authors discuss acceleration techniques aimed at improving computational speed and storage.In "Bayesian inversion of pressure diffusivity from microseismicity," Poliannikov et al. develop a probabilistic model that ties f luid pressure during injection (in hydraulic fracturing) to observed microseismicity. The authors propose a Bayesian reformulation of the (Shapiro et al., 2002;Shapiro et al., 2005aShapiro et al., , 2005b physical pore-pressure/seismicity model, which is based on the Mohr-Coulomb theory of rock fracturing. The authors' approach produces a model that captures the essential parameters that control f luid pressure, rock failure, and seismic wave propagation that can be used for forward predictions and inversions. The authors also present a probabilistic framework that allows rigorous uncertainty analysis, which quantifies prediction and inversion errors, and helps the user to find ways to improve the quality of predictions by identifying dependences between uncertainties at different stages of the model. The inversion is for diffusivity of the fracture system during injection, which the authors stipulate is likely to be inadequate to forecast production capacity, for example.Cheng and Sacchi address the problem of deblending data generated from simultaneous seismic sources in "Se...