Haephiteus said:
1. Can a recorder with the voice activation on, record an EVP?
Hi Haephiteus! (Where does your name come from, BTW?)
Now, as you probably know, I don't really put much stock in the idea that EVPs are the spectral voices of ghosts. That aside, most of the EVPs I've heard are buried in the noise floor. In other words, they're sounds that would be too soft to trigger voice activation.
The second problem with voice activation is that it isolates a piece of sound, and therefore doesn't record any context that might make it clearer what that sound was. Without a constantly-running tape, for most tape recorders there's no real way of figuring out what time an EVP happened, and so there's no way of knowing any mundane causes. Worse, it might record, for example, half of someone muttering to themselves, and that might sound ghostly and inexplicable. So in terms of continuity of evidence, I would consider voice-activated recording a strike against.
I'm not exactly blown over by EVPs anyway– there are just too many possible explanations for a sound appearing on tape.
2. Is it possible for a voice recorder to pick up sound waves (voices) near power lines?
Power lines could conceivably create a 60-Hz hum which your IC recorder might modulate into speechlike tones. Hard to know without an experiment or two. I doubt that the field would be strong enough at ground level to affect things.
3.In the winter time, when getting out of a vehicle, how long does
the moisture (if thats what it's called) from the exhaust, last in the
air?
(let's say no wind)
Tricky. According to Wikipedia, car exhaust is mostly nitrogen, water vapor, and CO2. So I'm assuming that the visible section is a mixture of steam and particulates, and how long it takes to dissipate would depend on the humidity and air pressure. Not my specialty, so I'll leave this one for someone brighter to answer.