if you bend a thick wire of nitinol (nickel titanium alloy, discovered on accident, aka shape memory alloy) quickly, it heats at the site of the bend and that i

if you bend a thick wire of nitinol (nickel titanium alloy, discovered on accident, aka shape memory alloy) quickly, it heats at the site of the bend and that is cool, but paper clips do the same thing. once you've let the thick wire settle back to room temperature---here's the cool part---quickly force it straight again and it gets suddenly very cold at the site where the bend was. nitinol is neat