Why Don't Clouds Fall?
Clouds don't fall because the rising air currents that create them keep them aloft. The air within and surrounding a cloud is less dense than the air closer to the ground. This density difference allows the cloud to essentially "float" on the denser air below.
- Rising Air Currents: Clouds form when warm, moist air rises. This rising air is less dense than the surrounding cooler air, causing it to continue ascending. Water vapor condenses within this rising air, forming the visible cloud. The upward movement of the air counteracts the downward pull of gravity.
- Density Differences: The water droplets and ice crystals within a cloud are small and light. While a cloud's total weight is substantial (it can weigh tons!), the individual components are small enough and dispersed enough that their overall density is less than the surrounding air. This density difference is crucial to the cloud's ability to remain suspended.
- Falling, But Slowly: The water droplets and ice crystals are falling, but their rate of descent is incredibly slow due to their small size and the upward movement of the air. They are essentially caught in a constant upward current. Only when these water particles grow large enough – through condensation and collision – do they overcome the upward current and fall as precipitation (rain, snow, hail, etc.).
As stated in multiple sources, even though a cloud weighs tons, it doesn't fall because the rising air responsible for its formation keeps the cloud floating in the air. The air below the cloud is denser than the cloud, meaning the cloud floats on top of this denser air near the Earth's surface. ([Source: USGS, Reddit, various other articles](https://www.usgs.gov/media/images/a-cloud-can-weigh-much-airplane-why-doesnt-it-fall, https://www.reddit.com/r/explainlikeimfive/comments/15c76z7/eli5_how_do_presumably_very_heavy_clouds_stay/, https://pumas.nasa.gov/sites/default/files/examples/01_16_01_1.pdf, https://www.quora.com/Can-we-walk-on-clouds-Why-dont-clouds-fall-to-Earth, https://www.zmescience.com/feature-post/natural-sciences/climate-and-weather/why-clouds-dont-fall/, https://medium.com/a-microbiome-scientist-at-large/why-dont-clouds-fall-down-42f618855585, https://www.scientificamerican.com/article/why-do-clouds-float-when/, https://www.wired.com/story/if-clouds-are-made-of-water-how-do-they-stay-in-the-air/, https://mathematics-and-physics.quora.com/Why-if-the-Earths-gravitational-pull-is-downwards-are-the-clouds-not-pulled-down-to-Earths-crust-The-rain-that-is-i, https://www.livescience.com/planet-earth/why-do-clouds-float)).
