I describe how some materials can change temperature when a magnetic field is applied to them. 6:03 - update on ruby laser https://www.kjmagnetics.com/gap.calculator.asp http://www.sigmaaldrich.com/technical-documents/articles/material-matters/advanced-materials.html https://www.youtube.com/watch?v=WlKKKMTA7XM http://www.reddit.com/r/AppliedScienceChannel/ http://en.wikipedia.org/wiki/Magnetic_refrigeration