Re: "Everything between sample points is lost" (@the spectacularly refined chap)
"FOR FUCK'S SAKE HAS NOBODY EVEN BOTHERED TO READ THE ARTICLE?
Read the quote again: "Everything between sample points is lost". If there is a signal faster than that it is gone. That is not conditional on anything. You can argue about whether it is relevant or not but it is gone never to be recovered. That is precisely what Shannon said."
Strident, profane, but wrong. If you understood sampling theory you'd know that frequencies above half the sampling rate are not "gone"; their energy is aliased back down into the baseband (the spectrum is effectively "folded" back on itself). It's actually more complicated than that, but that's close enough for this discussion. The article's phrasing is unfortunate, at minimum, but I lean toward "wrong".