This is the starting page for the NMR section. Nuclear Magnetic Resonance (NMR) is an instrumental technique that looks at atoms. Why it works is the subject of much conjecture and several theories have successfully attempted to explain it, but no single theory describes everything about the process. It is a sad state of affairs that the question of why it works has remained unanswered since the 1940s. I blame Heisenberg and his uncertainty principle. If you think fundamental aspects of reality are unknowable then of course there is no reason to pursue them. Engineering has advanced rapidly since then, but physics will remain at a standstill until the uncertainty principle is discarded.