Fluid dynamics and mathematical modelers at Kyoto University have made a groundbreaking discovery that challenges the fundamentals of Newton’s third law of motion. In a research paper published in PRX Life, Kenta Ishimoto, Clément Moreau, and Kento Yasuda present their findings on the perplexing ability of tiny creatures, such as sperm and algae, to effortlessly navigate through viscous fluids. By observing the movement of these organisms, the researchers sought to uncover the mechanisms that allow them to seemingly defy Newton’s law.
Newton’s third law of motion suggests that for every action, there is an equal and opposite reaction. Typically observed through experiments involving physical objects, this fundamental law governs the motion of objects in our everyday world. However, nature has a fascinating way of challenging even the most established scientific principles.
Certain organisms have evolved mechanisms that enable them to conserve energy while traversing through fluids, thereby reducing their need for food and enhancing their chances of survival. The researchers at Kyoto University noticed that algae and sperm cells appeared to move through their respective fluids with an inexplicable ease, given the viscosity of the medium. Intrigued, they embarked on a quest to unravel this mystery.
To investigate the motion of these tiny cells, the team closely examined Chlamydomonas algae and human sperm cells under a microscope. Their observations revealed a commonality – both organisms used flagella to propel themselves forward. The flagella, hairlike appendages, create wave-like movements that push and pull the cells through the surrounding liquid. This movement, in accordance with Newton’s third law, should elicit significant resistance from the fluid, impeding their progress. However, the reality proved otherwise.
As anticipated, the researchers observed the flagella of a swimming sperm wagging rhythmically. However, they also made an intriguing discovery – the flagella exhibited a unique flexibility, which they referred to as “odd elasticity.” The flagella bent in minute ways in response to the liquid’s resistance, allowing them to avoid an equal and opposite reaction. Consequently, the energy of the flagella and the cell itself was conserved, enabling efficient locomotion.
The findings presented by the Kyoto University team shed light on the extraordinary adaptations of sperm and algae, revealing the intricacies of their movement through viscous fluids. Understanding these mechanisms could have far-reaching implications across various fields, including biological and medical research. By studying how these organisms defy Newton’s third law, researchers may discover novel approaches for exploring propulsion systems and developing more efficient technology.
With each new scientific discovery, the boundaries of our understanding are pushed further. The remarkable ability of tiny organisms like sperm and algae to circumvent Newton’s third law invites us to explore the hidden complexities of the natural world. By diving into the mysteries of fluid dynamics, researchers at Kyoto University have unraveled a fascinating phenomenon that showcases the ingenuity of evolution. As we continue to unlock these secrets, the possibilities for advancing our knowledge and technology seem boundless.