SPOCK: I have a blip on the motion sensor. Could be the intruder.
KIRK: Go to full magnification.
SULU: Screen is on full mag, Sir.
KIRK: I don't see anything. I can't understand it.
SPOCK: Invisibility is theoretically possible, Captain, with selective bending of light. But the power cost is enormous. They may have solved that problem.
"How do you know?" is a dangerous question here, because we can easily say that Spock "in reality" would never use those words if contrasting the current cloak against the well-known Klingon ones (which actually behave identically to the one in "BoT") or Xyrillian or Suliban ones or whatever.
Why wouldn't he, though? If we know Starfleet already has by this point tech/methods that can readily penetrate such cloaks—which we
do—then we can quite plausibly believe that these would be automatically implemented as part of a starship's standard sensor suite (especially one assigned to Neutral Zone patrol), thus allowing any and all such
specifically known cloaks to be
discounted without comment as potential explanations for the effect seen. But this would still leave the theoretical possibility of one that
isn't so known.
Thus, Spock is following essentially the same process of logic as seen in TUC, but silently, eliminating what he
already knows
cannot be the case from his verbal assessment and limiting it to what he knows
can. Based on an already-well-established historical pattern of successive cloaks being cracked by successively better-attuned sensors, he posits a new "theoretically possible" cloak based on the same principle as known obsolete models, but improved in its efficiency—yet still coming at an
even higher power cost, thus explaining why its use limits the vessel to impulse where others didn't, necessarily—to the point where it can once again
almost fool the sensors rather than let off a whopping great energy surge that would be readily identifiable both on scanners
and (at least under certain conditions) as a
visible distortion on the viewscreen as seen in STIII, all with no need of the
concept itself being novel or unproven in the slightest.
And again, on the other hand, it's alternatively equally plausible that he might not be contrasting
any particular type of invisibility screen against another; he may only be contrasting the
theoretical possibility that one of any sort is in play here against
any other possible theory that might explain what's been seen. Legendary Thasian powers of de-materialization, teleportation, or indeed a spore drive!
But we can ignore that and say that Spock is theorizing on how exactly to defeat this latest model. It's just that we then lack the proper responses from the other characters, the most significantly the bit where our heroes remember that Romulans are historically infamous for creating visual obfuscation.
Well, this stuff is ancient history to them, hence Spock needing to provide a history lesson—probably a patchy and inaccurate one, based on records equally so—at the outset. No one seems to remember that Romulans are historically infamous for painting their ships with birds, either, until Stiles is able to remind them by virtue of having had relatives who personally fought in the war. Stiles wouldn't feel the need to preemptively remind them of the visual obfuscation, if he indeed knows of that too, because there's as yet been no indication it even
might be in play at that point, and like all of them he would also surely know of and have faith in the standard prophylactic countermeasures put in place in the wake of both that war and the more recent one with the Klingons. (And by the point they come up lacking, Spock has already instantly beat him to the explanation, no doubt further fueling Stiles' ever-mounting chagrin at being shown up and dismissed by the soon-to-be-suspected Vulcan stooge, despite perceiving himself to be a better authority on the subject than anyone.)
Well, a couple of spinoffs later, we learn that Vulcans do love to debate whether the things they just witnessed are possible or not...
(In this instance, Spock would be especially entitled to, as he's contemplating an obvious
illusion, a thing of debatable reality by definition.)
More like hold out for an explanation of what's been seen that doesn't defy their preconceptions of what is and isn't "theoretically possible"!
And, speaking of
illusion, given his past experience with Talosians and salt vampires, Spock is
also in something of an unique position to have
this in mind as
yet another "theoretically possible" explanation of his observations, held in reserve along with others due to it being internally judged less likely in the present circumstances than the theoretical possibility of an improved cloaking device!
-
MMoM
