We’ll give you a minute to wrap your brain around that. You can’t? Neither can we.
It works like this. Generally, when you compress something, you’re collapsing it into a specific stable state (i.e. squished). Anything that you compress that doesn’t do this is inherently unstable. Think any pressure vessel explosion you’ve seen on YouTube; it has to collapse into a stable state.
So researchers have designed a material, in theory, that allows you to compress something and have it stretch. It works by having four particles in a row. The inner two particles are attracted to each other, but the charge is weak, and easily broken when the material is stretched. The two outer particles then attract the two inner ones.
But when it’s compressed, the two inner particles reconnect their bond, meaning the material expands. The basic application of these is pressure and force resistance, keeping things from deforming. And, of course, screwing with people.
image courtesy New Scientist