The minds behind the Hard Science YouTube channel have given us a crash course in the exciting world of non-Newtonian fluids in the most awesome way possible — by biking across a pool of cornstarch that is, at once, both solid and liquid.
By creating a mixture that’s two parts cornstarch to one part water, the team was able to create a liquid that actually changes its viscosity according to the amount of force applied to it. So just like in the cornstarch wonderland above, you can actually walk on a liquid so long as you move fast. The reason this is possible?
In non-Newtonian fluids, the particles are packed very close to each other (they are touching), but they are still able to slip by each other. When you move the mixture slowly, the suspended particles have time to move and slip by each other — this is how a normal liquid acts. However, when you suddenly apply pressure to the mixture, the particles do not have enough time to move out of the way as they are quite large. This causes them to stay right where they are which causes the mixture to act and feel like a solid.