Raindrops can be round or flattened depending on their size and the resistance of the air. Smaller drops tend to remain spherical due to their low mass and surface tension, while larger drops can flatten due to air resistance during their fall.
At first, each drop of water naturally takes the shape of a perfect sphere. Why? Because water spontaneously seeks to have the smallest possible surface, and that shape, precisely, is the sphere. This phenomenon can be explained by surface tension, a kind of invisible force that acts like an elastic envelope, pulling all the tiny water elements inward. As long as the drop is small and stationary, shielded from disturbances, it remains perfectly round. But as soon as it starts to fall and gain speed, that's a different story!
When a drop falls, it encounters air resistance. This confrontation creates a stronger air pressure beneath the drop than above it. As a result, the base of the drop is pushed upward, causing a flattening. The faster the drop falls, the greater this resistance becomes, and the more the air deforms the drop into a sort of small, slightly domed pancake rather than a perfect sphere. This constant struggle between the air and the drop explains why their shape can become very different from the initial sphere.
Size changes everything! Small drops, like those from a light drizzle, remain almost round because the surface tension is stronger than the forces caused by falling through the air. As the drops get larger, they progressively become more and more flattened. Why? Simply because a large drop, falling faster, experiences more air pressure from below, which flattens its shape. Beyond a certain size, drops become downright unstable and burst into several smaller pieces as they fall. This phenomenon limits the size of the drops we receive on our heads during a heavy downpour.
When a raindrop falls, the faster it goes, the more the surrounding air resists its passage, creating a sort of invisible cushion underneath the drop. This pushes on its lower part and forces it to flatten slightly. A slow drop will be rather round, while a fast drop will become increasingly flat and wide on the bottom, taking on the shape of a small disk or, in some extreme cases, resembling almost a miniature parachute. Basically, if you see a very flattened drop, it’s likely falling quickly and encountering significant air resistance during its fall.
Surface tension is a bit like an elastic skin on the surface of the water, created by the attraction of molecules to each other. It's this invisible force that always pushes droplets to naturally adopt a shape as close to a sphere as possible, because it's the shape that requires the least energy to maintain. However, when falling, they encounter air resistance, which modifies their initial shape. The larger and faster the droplet, the harder it is for this surface tension to counteract the effect of the air, resulting in those sometimes slightly flattened shapes, like small pancakes. Conversely, for small slow droplets, surface tension is more than sufficient to maintain perfectly round shapes. So, it's a constant balancing act between internal forces (surface tension) and external forces (aerodynamic forces), which explains why droplets are not always as round and perfect as those we draw.
The maximum dimensions of a raindrop are limited: beyond a diameter of about 6 to 7 mm, the drop becomes unstable and usually ends up bursting into several smaller droplets during its fall.
It is estimated that approximately 505,000 billion liters of water fall to Earth each day in the form of precipitation, an impressive amount that represents a vital water cycle for life on the planet.
Contrary to popular belief, raindrops do not have the shape of tears when they fall. Small droplets are almost spherical, while larger ones flatten out and resemble more of a hamburger shape.
Rain has a distinctive smell called 'petrichor,' which results from an oil released by dry soil when it is moistened by rainwater. This unique scent is especially noticeable after a dry spell.
During the collision of droplets in the air, surface tension naturally drives the droplets to merge, thereby minimizing the energy of their shared surface. This phenomenon promotes the gradual enlargement of the droplets as they fall to the ground.
No, the speed of droplets mainly depends on their size and shape. The larger and heavier a droplet is, the faster it falls. However, beyond a certain size, droplets flatten significantly due to air resistance, thereby limiting their acceleration and stabilizing their falling speed.
Small droplets remain spherical due to the dominance of surface tension, a force that tends to minimize the droplet's surface. As the droplets grow larger, aerodynamic forces become more powerful, overcoming surface tension and leading to the flattening of the droplet.
Unlike common representations, droplets do not have the shape of tears during their fall. They are generally round or flattened due to surface tension and aerodynamic forces. The teardrop shape, often depicted, actually comes from droplets adhering to a surface, but does not reflect their true appearance when they fall.
Generally, a drop of water does not exceed 4 to 6 millimeters in diameter because beyond this size, it becomes unstable due to the aerodynamic forces exerted by the air. At this point, it often fragments into smaller droplets.
No one has answered this quiz yet, be the first!' :-)
Question 1/5
