Science Can’t Figure Out Why Some Liquids Flow

Scientists are still trying to understand why not all liquids flow in the same way. One recent study dove into the complexities of pusher fluids used for extracting oil and solved a decades-old mystery.

Fluids are a necessary part of day to day life. After all, without water you couldn’t live, and without chocolate syrup, well, what would be the point? But have you ever noticed that not all liquids behave the same? In fact, some of them do some totally bewildering stuff under the right circumstances, and even after decades of research scientists are no closer to understanding why.

One question about strange fluids may have finally been answered thanks to some glass beads and laser beams. All liquids that we encounter in the real world can be boiled down to one of two kinds. They’re either Newtonian, or non-Newtonian.

Newtonian fluids are pretty easy to grasp. Well, not literally in some cases—a Newtonian fluid like water would squirt right out of your hand. A Newtonian fluid obeys Newton’s Law of Viscosity which means its viscosity is constant. It doesn’t change when a force is applied to it.
Non-Newtonian fluids, on the other, less sticky hand, do change their viscosity…which can lead to some pretty zany shenanigans.

Still there are many more weird non-Newtonian behaviors scientists don’t have answers for. They may have just solved one riddle that’s stood for over 50 years.