Many people gaze at clouds, wondering if it’s possible to touch them. Their pillow-like appearance often prompts curiosity about their true nature. Exploring the science behind clouds reveals what one might experience if immersed within them.
The Composition of Clouds
Clouds are not solid entities but rather visible masses composed of countless tiny liquid water droplets or microscopic ice crystals suspended in the atmosphere. These minuscule particles are incredibly small, typically ranging from 5 to 50 micrometers in diameter. To put this into perspective, an average human hair is about 100 micrometers thick, making cloud droplets significantly smaller.
The air itself is also a major component of a cloud, with the visible water droplets or ice crystals merely dispersed within it. Water vapor, the gaseous form of water, is invisible, and it condenses into these tiny liquid droplets or ice crystals around microscopic particles like dust or pollen to become visible. Because clouds are made of these dispersed, lightweight particles and air, they do not possess the solidity that their appearance might suggest.
What It Feels Like to Be Inside a Cloud
Experiencing the inside of a cloud is akin to being enveloped in a dense fog, as fog is essentially a cloud that has formed at ground level. The primary sensation is one of wetness and coolness, as the tiny water droplets or ice crystals come into contact with the skin. This contact feels like a gentle mist, providing a damp feeling to the air.
Visibility within a cloud is significantly reduced, sometimes almost to zero, making it difficult to see more than a few feet ahead. This low visibility is a consequence of light scattering off the countless tiny particles. Passing through a cloud, whether hiking through a misty mountain, driving in thick fog, or flying in an airplane, means moving through these dispersed water droplets or ice crystals. The experience is largely one of a cool, moist environment with obscured surroundings.
Why Clouds Stay Up in the Sky
Clouds remain suspended in the atmosphere due to buoyancy and rising air currents. Warm, moist air is less dense than cooler, drier air. As air near the Earth’s surface heats from solar radiation, it expands and becomes lighter, causing it to rise, similar to a hot air balloon.
As this warm, moist air rises, it cools, and water vapor condenses into the tiny water droplets or ice crystals that form a cloud. These droplets are small and light, easily supported by gentle upward movements of air, known as updrafts. Updrafts are columns of rising air that continuously transport moisture and heat upward, counteracting gravity. The constant presence of these rising air currents keeps the cloud aloft, maintaining its visible form.