>>9242312>ship heat generation>radiation in space>distinguishing said radiation(s) from each otherWell, if we're talking one of those giant clunky black-hole driven starships, while yes, they would put out a buttload of radiation, they'd do so in one direction. As long as your spaceship is aiming towards the potential detection point, it's invisible, despite the ludicrous energy involved in its movement.
If you're talking about being invisible nose-to-nose with another starship, that's another thing. There's not a lot of feasible ways to make yourself invisible to detection at point blank range (like mere meters apart). I mean, there's all sorts of fancy visual cloaking materials, but, not only are they not all that effective close up, even your sheer mass is going to be detectable, if they are looking for it. You'd need some truly magic-tech level shit to negate that, and even at that fantasy level, if it had any logic at all, you'd probably be making yourself much more visible in some other way.
Though, to Star Trek's credit, generally, when some cloaked vessel is managing to ride near piggy-back next to a starship, it's because they aren't actively looking for it. Even modern submarines can snuggle right up next to each other unnoticed, provided neither is actively pinging - and there's been at least one nasty collision as a result of this.
And the old Millennium Falcon trick of blending with trash and getting out of the way of directional radar of a much larger vessel, while a bit silly, isn't entirely unfeasible. There's bound to be blind spots in large craft.
