For Sonja:
Sadly nothing quite as neat as a black hole grenade. If a magnet suddenly stops superconducting it is called a quench. When that happens all of the electricity in the coil (it's a big electromagnet) gets turned into heat and boils off the liquid helium bath it sits in. Best case: you get a whooshing noise and a big plume of vapor coming out of the magnet. Worst case: the wire that makes up the coil breaks or melts and you are witness to anywhere from $150,000 to several million dollars going up in smoke.
Helium is kind of interesting since you will never actually see it as a liquid. It vaporizes the moment it comes into contact with room temperature air, and even if you were in a room cold enough to keep it liquid it's almost perfectly transparent.
But if you get a leak that you can't shut off, you just leave the room. Since helium rises, swinging from a chandelier would lead to death pretty quickly. Liquid nitrogen is more likely to suffocate you since it sinks and doesn't leak out of the room as easily (or kill iphones for that matter)
But in any case, this lab was built to contain several of these magnets with proper ventilation and two ways to exit the room. I have had to work in some pretty sketchy ones where I was glad to have an oxygen meter with me.
And since I'm sure at least one of you is wondering: yes I have deliberately inhaled helium from a dewar like that just to hear myself talk funny. And I giggled, squeakily.
For mm:
We do this:
https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance_spectroscopyTo put it simply: we use big magnets and ridiculously precise and sensitive radios to selectively excite atoms and use the resulting signals to figure out how molecules are put together. It's the same technology as used in MRI machines that are in hospitals, just taking a slightly different approach.
Anyway enough nerd, back to the regularly scheduled fabulous.
