Chemical analysis can be an art form.

Nuclear Magnetic Resonance (NMR), the parent technology of Magnetic Resonance Imaging (MRI) has been an essential tool for characterizing chemicals since the 1950’s. Placing molecules in a big magnet makes many of their nuclei precess - rather like how a gyroscope twirls about when you spin it and tip it off-axis. Just like how you can tip a gyroscope over with a series of gentle taps if you get the timing right, we can tip the nuclear “spins” by “tapping” them with light if the frequency of the light matches the frequency of their spinning. Once we stop exciting the nuclear spins with light, we can let them relax back to their original state, and we can detect this relaxation with an antenna. The whole process is much like ringing a bell by tapping it then listening to the resonant sound it makes.

The fun thing is that the process can actually produce sounds! We excite the nuclei with radio waves, and we detect radio frequency signals back from them. But we’re mainly interested in the differences between the frequencies of different atoms, and the range is normally about 1 to 10 KHz ... which corresponds to th range of human hearing!

See, if we take the electrical signals from the instrument that normally just get piped in for digital analysis and instead amplify them, we can hook them u to speakers and listen to them!