I come forth to deliver a warning. The food you eat, the beverages you drink, the liquid running from all your taps – they contain the odourless, colourless chemical dihydogren monoxide. This chemical is known to be the basis of many adverse health effects, including gene mutation and cell lysis. It is home to countless pathogens and it allows the transmission of numerous diseases across the globe, yet we still expose ourselves to it every day. It has been and still continues to be a major cause of environmental erosion and the destruction of millions of residences worldwide.
I’m just kidding (not about what I described above though). Dihydrogen monoxide is simply a scientific name for water, one of if not the most important substance on Earth. This hoax has lain in the backdrop of the scientific community for the past thirty years, and encourages the general public to become more literate in science and to stay sceptical of cherry-picked information (but not too much of course).
On the contrary, I aim to list the the special properties of water and why they are important for the continuity of the living world.
- Water is a liquid at room temperature.
The existence of liquids is extremely important for the biological maintenance of multicellular organisms like us. Not only is water able to provide aquatic habitats for organisms to live in (try swimming in a solid, it’s not easy), but cells revel in liquid environments. This allows ease of access for the transportation of molecules within the human body. Hence why you would almost certainly die if your blood literally froze.
2. Water is colourless and transparent.
The survival of aquatic organisms was essential for the birth of land species, as they were the first multicellular organisms to develop. The transparency of water enables the transmission of sunlight for aquatic organisms to photosynthesise (to make food using sunlight). But of course, if there were no food, there would be no life.
3. Water is denser than air.
Okay, I know this seems ridiculously obvious, but imagine a world where all the liquid water on our planet was in the sky. In fact the water may escape into outer space and there’ll sadly be no water left for us land people. And ignoring the macroscopic changes to our planet, the higher density of water is able to support organisms as massive as whales. Water also supports and disperses reproductive structures such as larvae, and large fruits such as coconuts, allowing species to reproduce and thrive.
4. Water is denser than ice.
The ability of a substance to be denser in liquid state than in solid state is a very unique property endowed by only a few other substances. Yes, it is true that there would be no icebergs and the RMS Titanic may not have undergone her fateful demise, but this is a minor sacrifice for the development of complex life. When water freezes, ice forms on the surface of a body of water instead of from the bottom. Not only will the lower section remain in liquid state, but the icy layer insulates the water below and allows aquatic life to survive. So if you think about it, we wouldn’t be here to construct an RMS Titanic that could experience an iceberg-free ocean anyway.
5. Water is difficult to compress.
In general liquids have the property of being nearly incompressible. In the living world, water is an important structural agent, forming hydrostatic skeletons in worms and turgid plants. Like our skeletons, hydrostatic skeletons provide structure to small, soft-bodied organisms, but consist of fluid-filled cavities rather than bones.
6. Water has a high surface tension.
You may have experienced the concept of surface tension the hard way if you happen to have belly-flopped from a painful height (I am not suggesting this). The surface of water is home to many species of plants and aquatic organisms such as pond skaters, who are able to land on the surface of a body of water due to surface tension. In addition, small, light objects such as dust particles can lay on the surface of water, preventing marine ecosystems underneath from being suffocated.
7. Water has a low viscosity.
Viscosity is a term often used in physics and chemistry to describe how ‘thick’ a fluid is. Chocolate syrup for example has a higher viscosity than water, and thank goodness for that because water is then able to flow through narrow channels, like blood vessels or the stems of plants. Water is also able to act as a lubricant, for instance in mucus which eases the flow of food down the oesophagus (gullet).
8. Water is adhesive and cohesive.
Have you ever noticed that even though you pour out a drink, there is always some droplets left on the walls of the container? Adhesion and cohesion are the properties responsible for this phenomenon. Adhesion is the attraction between molecules of different substances, and cohesion is the attraction between molecules of similar substances. Intermolecular forces called hydrogen bonds gives water these properties, and this is because water molecules are polar (one side is more positively charged and one side is more negatively charged). Adhesion and cohesion allow capillary action, the ability to move upwards through narrow channels against the force of gravity (like when you use a straw). If it wasn’t for capillary action, plants nowhere nearly as tall as trees would be able to exist.
In fact, there are so many significant properties of water that I can’t even list them all in one post! But I promise I will be back with a list of more reasons why, to quote Leonardo da Vinci, ‘water is the driving force of all nature’.