HYPER lab members Jordan Raymond, Eli Shoemake, Greg Wallace, and Carl Bunge use a magnet to pull around liquid air droplets in TFRB.

One of the HYPER lab’s favorite demonstrations for visitors is magnetizing air — yes, the stuff you’re breathing can be magnetized. We play around before these demos and come up with amazing ideas, and we’ve got patent-pending technology to prove it.

Here’s what you’ll need to do this:

  1. Support a small metal container over a surface. In the picture above we’re using a thin-walled stainless steel beaker and a test-tube stand.
  2. Fill the metal container with liquid nitrogen (make sure you’re following all necessary safety precautions before handling liquid nitrogen).
  3. Because the normal boiling point temperature of liquid nitrogen (~77 K) is less than the normal boiling point temperature of air (~80 K), liquid air will begin to condense on the outside of the container.
  4. Use a small pyrex dish to catch the liquid air droplets as the drop off of the metal container.
  5. Use a neodymium or other strong magnet below the pyrex dish to pull around the liquid air droplets.

Here’s a video:

Here’s an explanation of why this happens:

Liquid oxygen has two unpaired electrons in it’s outer 2p electron orbits. These vacancies give the O2 molecule a net spin, the spin in turn is the movement of electrons, which will interact with a magnetic field. It’s called paramagnetism — unusually magnetic — and only occurs when oxygen is dense, and slow enough, to be significantly influenced by the magnet.

What it does:

For most kids, this is a literal magic trick enabled by science. “WOW!” is all too common. For engineers working in cryogenics, playing like this causes a “what if we put magnets on _____?”!!” moment that can lead to innovation.

Happy magnetizing!