As for "leaving it where it was," I doubt the sensor would have done much good if they left it in a storage locker somewhere.
A sensor known to be capable of charting gaseous anomalies is in fact incapable of doing that unless installed inside the torpedo tube? You do realize you are making no sense...
Sulu obviously charted those anomalies without installing his sensor in one of his torpedoes. Spock would be a complete idiot if incapable of conceptualizing and executing the same.
Except... where's the torpedo, then? Invisible?
Huh? Torpedoes are always blatantly visible, as fireballs several meters across. ST6 is no exception.
The Class 1 or Class A probes are somewhat different in that their comparable fireball is distinctly around the aft part of the instrument, not all around it. But that actually makes good sense if we assume such a probe is a much larger device, with a "torpedo" grafted in its ass and glowing the normal way, but with a payload riding ahead of it.
There's nothing wrong with the idea of the coffin thing being hidden by the glare of the glowing (propulsive?) thing. Today's missiles may look like telephone poles with a trailing flame, but that's only because the flame is not particularly bright and in fact effort is made to minimize it visually. Photon torpedoes have every excuse of featuring a brighter, more engulfing flame.
After the 22nd century, photon torpedoes continue to evolve, becoming (arguably) more accurate, more sophisticated, more powerful. Spatial torpedoes, however, fall out of use, despite the apparent portability of photon warheads, despite the improved propulsion technologies (indeed, a 24th century spatial torpedo would be essentially a Class-8 probe with a tricobalt device in the warhead). So for whatever reason, Starfleet does not appear to carry straight projectile weapons anymore.
Or Starfleet drops an outdated propulsion system of projectile weapons in favor of a more modern one, namely the one dubbed "photon torpedo".
There are many upsides to considering the "photon" part as describing the propulsion element rather than, say, the warhead. But none require making the weapon "non-projectile" in nature.
I'm drawing both on backstage evidence that photon torpedoes were not originally meant to BE missile-type weapons, but a totally distinct technology similar but with slightly different properties as phasers. Physical casings made their debut in TWOK and appeared again in TUC; both times can be made consistent with the original TOS conception, and that would explain a lot of OTHER things that don't make sense about photons.
Two points of disagreement there: lack of evidence of any sort of intent on the part of the makers of TOS, one way or the other - and the obvious advantages of simply making TOS compatible with the bulk of the evidence, rather than vice versa.
Incorrect, demonstrably so from "Maquis ptII" where photon torpedoes flying past a runabout have a glowing core visibly smaller than the runabout's bussard collector.
How is that relevant? The craft firing those fireballs couldn't have carried coffin-sized projectiles anyway; ergo, whatever the craft did carry, could fit inside the fireball.
The torpedo casing should be plainly visible in front of it from at least the forward angle, if it's intended to be there at all.
Obviously not, unless the glow is somehow limited to the aft sector only. There is no particular reason to think it would be limited that way; warp engines don't glow from their aft ends only, except when the designers specifically want them to (say, the Kelvin).
Even the VFX artists don't seem to believe there's any PHYSICALITY to the weapon in flight
You can't claim such a thing. What they gave us is physical enough: it flies through space at finite speed, reasonably often in curved patterns. It isn't an intricate shape requiring hours of motion control work; it is an affordable fireball. But that in no way makes it "aphysical", any more than a star is aphysical.
The bright rectangle torpedo from TMP
Umm, the elongation of the bright dot would be an optical phenomenon inherent in traditional moviemaking, not a particularly convincing argument for the shape of the glow "in reality". But it's a very nice optical phenomenon... Conveniently lending itself to some smooth retconning.
In TSFS when the Bird of Prey was arming the torpedoes the torpedo tube was glowing with static-like charges, which looked like it was building up an energy ball.
Indeed. And the sparkling continued at the point of impact, spreading over the victim. A special feature of this special weapon - but whether it's carried to the target all by itself, or riding on a physical object, we can freely speculate on.
Perhaps that's what torpedo "launchers" always do - wrap the projectile in that (propulsive?) field... Klingon wraps would of course be more coarse than Federation ones, just like their ships are dirtier, their sliding doors noisier, etc.
Timo Saloniemi