Make a cloud—quickly. Simply open a can of soda and notice the cloud that forms for a moment over the opening. Why does the cloud form? The explanation is that bubbly drinks are held under pressure in...

Make a cloud—quickly. Simply open a can of soda and notice the cloud that forms for a moment over the opening. Why does the cloud form? The explanation is that bubbly drinks are held under pressure in cans. When you open the can, moist air escapes and quickly expands. Expanding air cools—to its dew point, as you can see.