Vanessa Hudgens

What is this called? It has to do with magnets, gravity, cold temperatures, and liquid nitrogen?

I watched this show on a science channel a while back and it had to do with extremely powerful earth magnets opposing one another and then, while holding them in place, you dip the magnets in liquid nitrogen (I think) and the magnets stay in that same position no matter what you stack on them or what direction you turn them… sorry I can’t give more information and I’m not saying this very professionally, but I’m hoping that I can find what it is. If more information is needed, I’ll see what I can do, just let me know!