Magnetorheological Fluid was a non-Newtonian fluid that could dampen bad vibrations from earthquakes and such. This saved lives.
A Newtonian fluid like water was a fluid whose stress vs. strain rate curve was a line and passed through the origin of a graph. The constant that resulted was the viscosity or resistance to flow. This was one of Isaac Newton's discoveries in alchemy as it became chemistry. However, in non-Newtonian fluids, viscosity was dependent on shear rate instead. For example, ketchup thickened at rest, so it was hard to get it out of the bottle. But if a person got the reaction started then the ketchup would thin and flow. Another notable example was a mixture of corn starch and water that was called Oobleck. The name was taken straight out of the Dr. Seuss book, Bartholomew and the Oobleck. But that was where all similarities ended. If a person were hit oobleck softly, he/she would pass through. Hardly, then oobleck would become a solid. In the early 21st century, a similar non-Newtonian fluid was put to work to stop bad vibrations. It was called Magnetorheological fluid or MR fluid. (Note: Do not call it Mr. Fluid.)
Tech Level: 10
Magnetorheological fluid or MR fluid was a fluid made of oil with iron particles in it. Put a magnetic field near it, and the iron particles would align. The thickness could vary. Lord Corporation in North Carolina first used this for shock absorbers in Humvees. Without MR fluid, a humvee would just bounce on a bumpy road, and the shock absorber would die. With MR fluid, an electromagneet, and a computer that controlled it, a humvee would not bounce because the shock absorber was tunable. The shock absorber would die eventually, but it would last longer. Eventually, MR fluid was used buildings which survived earthquakes and bridges that did not shake in the wind. Many peoples lives were saved.