I took this photograph at a beach a few minutes from my home. It isn’t a great picture, but it’s interesting because it reveals some important characteristics of water and our planet that were essential for the origination and evolution of life on Earth.
Earth, as demonstrated in this picture, has just the right combination of surface temperature and atmospheric pressure to allow water to exist in all three physical phases: liquid (the ocean water), solid (the ice), and gas (the clouds). Clouds are not strictly just gases because they actually consist of water in all three phases including water vapor, which is a gas, and tiny water droplets that form when the water vapor condenses around airborne particles of dust and ice crystals.
The picture highlights another important physical characteristic of water - ice floats. If ice sank the oceans would’ve frozen solid long ago, and the complex, multicellular organisms with the emergent property of consciousness called people probably wouldn’t exist.
Monte