Leonardo da Vinci's water world
In his lifetime, Leonardo da Vinci designed too many things that were ahead of its time. But many people do not know that this scientific giant has been obsessed with water all his life. He has depicted water countless times with his own pen, and he is not just recording the scenery of water, but exploring the secrets of fluids. Leonardo da Vinci's earliest painting of water, now in 1473, is a landscape painting of a river cascading down a rocky waterfall and flowing along a valley; 45 years later, his last "water work" depicts a flood that washed away the earth. Between 1508 and 1511, Leonardo da Vinci studied the hydrodynamic properties of water in detail, apparently intending to write a research article on the subject, but this article was not completed. More than five hundred years ago, Leonardo da Vinci observed the movement of water in countless details, and he made a keen analysis of the linear and circumferential characteristics of the forms of water flow, but the super-complex nature of water as a fluid made it impossible for him to find a universal law that could describe flow. Leonardo da Vinci happened to be a master painter who was adept at drawing things using perspective, cross-section, and explosion, which was the most effective scientific method of analytical analysis before the invention of X-ray fluoroscopy equipment. In his notes, Leonardo da Vinci demonstrated the wonderful realm of water flow with his superhuman painting skills.
The most elaborate of Leonardo da Vinci's research paintings on water cover two research directions. The first is the state of the water flowing through the flat-like obstacle. Leonardo da Vinci was amazed by the stability and repeatability of the "pattern" of the water flow around and behind the obstacle, and there was evidence that the flow was not chaotic, but governed by the laws of physics. In notes on the other side of the work, Leonardo da Vinci attempts to illustrate these principles from angles of incidence, impact, and reflection. Below, Leonardo da Vinci meticulously depicts the flow of water from a high-rise channel to the pool below. This is a more complex and elaborate study: from the water face down deep, multiple layers of swirls appear, each of which has many bubbles that form concentric circles and expand without interfering with each other. Leonardo was certainly not a sober observer, and he wrote elsewhere such words as "beautiful scenes of rippling waves" and "the beautiful movement produced by one element (air) penetrating another (water)".
In his manuscript, Leonardo da Vinci described in his own insights the formation of waves under the action of wind and how water and eddies form complex vine-like flow forms under the surface of the water. The most amazing thing is that Leonardo da Vinci took the lead in proposing the use of special equipment for "experimental research". The manuscript clearly records the experimental equipment he intended to make—a rectangular ceramic sink 116 centimeters long and 29 centimeters wide, with four walls made of glass for easy observation. To show how the fluid moves, Leonardo da Vinci also considered adding a small plant seed to the water, much like later generations using a stain in a similar experiment. This experimental concept undoubtedly demonstrated the scientific spirit of Leonardo da Vinci. The manuscript shows that one of Leonardo da Vinci's biggest concerns was how the liquid at the bottom would change as the air flow blew through the surface of the sink from one end, and he thought that objects under the water might move in the opposite direction of the wind.
Leonardo da Vinci even extended fluid test models to geological research. He believes that when studying the problem of the flow of water affecting the banks of the two rivers at the confluence of the two rivers, simple simulation experiments can be carried out using sand. He even suggested making a large model of the Mediterranean Sea and its surrounding fjords and rivers to reconstruct the geological formation of the region. He speculated that the Strait of Gibraltar would become wider over time, eventually turning the Mediterranean into a giant river— an extension of the Nile.
Leonardo da Vinci's manuscript surprised researchers every time. These manuscripts confirm that some of Leonardo da Vinci's knowledge of liquid turbulence did not come entirely from observations of natural landscapes, but from experimental observations of vortex motion. In the past, it was always believed that many of Leonardo da Vinci's scientific research results were not published and disseminated, and had little impact on the development of science and technology in later generations. However, recent research has shown that a considerable part of Leonardo da Vinci's manuscripts were spread in the form of manuscripts in geological surveying and mapping circles as early as the 17th century, and it is clear that, to some extent, Leonardo da Vinci's research must have ignited many new creative sparks.
