Science Can’t Figure Out Why Some Liquids Flow..!!

Fluids are an essential component of daily life. Water is crucial for survival, while chocolate syrup adds enjoyment. However, not all liquids behave the same way. Some exhibit fascinating behavior under specific conditions. Despite years of research, scientists are still puzzled by certain fluid properties. Recently, a question regarding peculiar fluids may have been answered, thanks to glass beads and laser beams. In the real world, all liquids can be categorized as either Newtonian or non-Newtonian. Newtonian fluids, like water and chocolate syrup, have constant viscosity. On the other hand, non-Newtonian fluids, such as quicksand and oobleck, change viscosity under force. These distinctions lead to unique characteristics and behaviors in different fluids.

Cornstarch is present in it, however, there are laws against vandalism, so it is important to be cautious. Certain fluids exhibit an increase in viscosity when subjected to force, but the opposite can also be true. Ketchup falls under the category of non-Newtonian fluids known as pseudoplastics. In the absence of force, it remains stationary, but when the back of the bottle is struck, the viscosity decreases and the ketchup flows out. At a molecular level within the sauce, long chains of atoms known as polymers become entangled and hold firm. However, when they are agitated or shaken, they elongate and align, allowing the thick red paste to move freely, hopefully onto your french fries, although it may end up on your pants as well. Scientists have yet to fully understand many other peculiar non-Newtonian behaviors.

One particular mystery that puzzled researchers for over 50 years was first observed in the 1960s. Engineers were trying to extract oil from the ground using fluids containing long-chain polymers. Pumping these pressure fluids into the ground at a certain rate worked effectively, but increasing the flow rate caused the fluids to become significantly more viscous, similar to oobleck. This behavior was only evident when the fluids flowed through the tiny spaces between soil particles. Interestingly, when not constrained within the porous medium, the fluid's viscosity actually decreased as more force was applied, akin to ketchup. Initially, scientists speculated that the polymers were blocking the soil pores, but this couldn't explain why the fluids flowed easily when the flow rate decreased once again. It wasn't until a recent study was published in late 2021 that scientists believe they may have finally unraveled this mystery. One of the challenges they faced was the opacity of soil and other porous media, making it difficult to observe what was happening within.

To overcome this, they developed a custom medium using glass beads and formulated a polymer solution with the same refractive index as the glass, ensuring that both the liquid and solid would refract light in the same manner. The researchers introduced a red dye into the solution to visualize the movement of the fluid when hit with a laser. They also included tracer particles that emitted a different color when excited by another laser. By observing the fluid flow at various speeds, they discovered that the long polymers within it began to tumble as the fluid accelerated. This tumbling action caused the fluid to push on neighboring molecules, resulting in elastic turbulence and the formation of eddies that slowed down the entire fluid.

The researchers believe that this newfound knowledge on the sudden increase in viscosity of pusher fluids could be beneficial for groundwater purification. It might assist in creating new polymer solutions capable of pushing water through rocks and trapping contaminants in the process. However, further research is required as elastic turbulence remains not fully comprehended. Perhaps this will be the next mystery to unravel, or maybe we will first uncover the reason behind the preference for ketchup on scrambled eggs, even though it is unrelated to its non-Newtonian properties.