One thing I never figured out was how a starship can, from orbit, read bio-signs of any given species and determine which one is human, Vulcan, etc. Is that realistically possible?
It's probably less a matter of sensor tech and more a matter of crunching the numbers after the data is obtained. We have seen how good-quality optical imagery one can get from orbit in Trek (or in real life, for that matter). Do that on a wide enough spectral range, and you can certainly establish things like body temperature, heart rate, the exact aroma of sweat, etc. Yes, we could do that today, given enough processing time. Trek just cuts down on that time with superior computing. You can of course add futuro-sensors to the mix, because Trek allows for futuro-technologies. If you can scan for tri-isomatic delta waves, that's probably helpful in some way - and especially if only telepathic species or species with tri-isomatic antennae emit those. Timo Saloniemi