Water is arguably the most important substance on our planet. Without water life as we know it on earth would not exist. Today’s IFOD is about five of the most amazing things about water.
FROZEN WATER FLOATS: A very strange thing about water is that it’s solid state, ice, is less dense than its liquid state. Most molecules contract when chilled and have solid states denser than their liquid states. Water, in liquid form, does contract at first when chilled but as as it approaches freezing it actually begins to expand. By the time it is solid ice it is almost 10% more voluminous than it is as a liquid. “With almost any other substance, parking molecules on a regular grid would make them sit closer together than when they’re allowed to roam free. But water’s not like that. [Water’s] growing crystal is less dense than the water around it, and so it floats.” Source.
If ice didn’t float it is possible life on earth wouldn’t exist as the oceans would freeze from the bottom up and earth would now be covered with solid ice. Because ice floats, when a lake or ocean freezes the top layer of ice traps in heat and keeps the rest of the water from freezing.
FREEZING AND BOILING POINTS: Water is the only natural substance that is found in all three physical states—liquid, solid, and gas—at the temperatures normally found on Earth. This is a very important property of water as water vapor – the gaseous state of water – is a key greenhouse gas. Without water vapor the earth would likely be uninhabitable due to being too cold. Additionally, water evaporating and turning to vapor creates clouds and is required for rain and snow to occur.
INCOMPRESSIBLE: Like most liquids, water is not compressible under most conditions. This means that when water fills an area, you can’t put more pressure on the water to create an air pocket. Thus, when water fills an area putting pressure on water causes it to want to escape to a less pressure area. This attribute of water is what gives us water pressure in hoses and pipes. Read more on Water Towers and Water Pressure.
WATER’S EXTRATERRESTRIAL ORIGIN: Our water likely came from asteroids impacting the earth early in earth’s history. Read more here.
THE AMOUNT OF WATER ON EARTH ISN’T AS MUCH AS YOU’D THINK: Over 70% of the surface of the earth is covered by water, but in the grand scheme of things, it’s a pretty thin layer. In fact, according to the USGS, “if we could gather ALL of Earth’s water — from the oceans, lakes, streams, rivers and even the polar ice caps — into a single drop, it would have a diameter of just 860 MILES.” That’s a really big drop of water as it would contain 332,500,000 cubic miles, but as compared to the size of our planet – 7,917 miles in diameter – a mere 860 miles is tiny. Here’s picture (the smaller drop of water is the fresh water):