What follows is an explanation of a phrase that Hirsch uses in most of his papers, “hole-electron asymmetry of condensed matter”. The explanation was adapted from one of Hirsch’s papers[1], that can be found on arxiv as well as Phys. Rev . B. Here’s a more complete derivation of the London penetration depth from the London Moment field equation mentioned below. [2] Hirsch frequently refers to the ‘hole-electron asymmetry of condensed matter’. In the article entitled “Electron-hole asymmetry and superconductivity”, he provides a nice picture of exactly what he means by this phrase. I adapted the explanation for a presentation I’ll give soon on the H-ray theory. The slides follow. A more complete and texty explanation can be found at the link above. The text that follows below is the very rough draft of some of the vernacular for the presentation. For those who are die-hard fans of watching people fumble with practice presentations, I've also posted the first run-through