Raindrops are not tears
Small raindrops are spheres. Large ones are flattened on the bottom, like hamburger buns. None of them are teardrops.
Established2 min read
Surface tension pulls a small drop toward a sphere. As the drop grows, air pressure on the underside flattens it and the top stays round. The equilibrium shapes were calculated and then photographed; they match.
Past a certain size, around several millimetres, the drop becomes unstable and breaks into smaller drops. That is why rain has a maximum drop size and why the cartoon shape never appears in the wild.
Caveats
- A drop leaving a faucet can be tear-shaped for a moment, while it is still attached. Falling rain is not.
- 'Hamburger' is a description of the cross-section, not a claim about edges being sharp.
Sources
- 1Beard K. V., Chuang C.. A New Model for the Equilibrium Shape of Raindrops. Journal of the Atmospheric Sciences 44, 1987.