(Here's another unpublished post, this one from late May. The reason it wasn't published and was forgotten will probably be obvious in the first sentence.)
So I'm watching Star Trek V . . . hey, yeah, I know, shut up, I'm drunk and I like the "What does God need with a starship?" line. Or maybe I'm a glutton for punishment. Whatever.
So anyway, I'm watching Star Trek V, and it dawned on me that the example does as much to prove torp shielding than anything else I've mentioned. From orbital height, the E-A shot a torp which, within seconds, impacted against the surface. A similar example appears in the Voyager ep with the small-size torp glows, "Alliances"[VOY2].
A ballistic de-orbit of a vehicle like the shuttle or like the old space capsules (or, actually, like the planned Orion space capsules) takes minutes, and even then they're heated to thousands of degrees. A de-orbit measured in seconds must therefore involve significantly higher temperature increases. Oh sure, most meteors don't reach a higher temperature than the thousands of degrees when they come barrelling in like a bat out of hell (or into it as the case may be), but sudden heating of a surface by thousands of degrees is surely not normal procedure. This is, after all, what many weapons are designed to do. So unless we want to believe that the very thin skin of a photon torpedo casing is capable of extraordinary levels of insulation, we must accept this as an independent proof that torpedoes have their own shields.