When the world first formed 4½ billion years ago it came with a huge amount of water that today covers about 70% of the planet in rivers, lakes, seas and oceans. It also makes up about 75% of the human body.
Now I’m going to ask you a question and I want you to think about it and have an answer ready in your mind.
How much of the water that was in the world 4½ billion years ago is still here today ……..?
OK. Here is the answer.
It is exactly the same amount today as it was then!
Rather strangely, it turns out that it is impossible to destroy water.
It isn’t vital to understand but if you are interested in why, it is all about simple science. If you don’t want to know that bit then just miss out the next paragraph.
Water is made up of hydrogen and oxygen (H₂O). Hydrogen is highly flammable and when it burns, strange though it may seem, it joins with oxygen and makes water. It can seem bizarre that burning a gas can make water but that just happens to be the way it is. So 4½ billion years ago when the world was made it had masses of hydrogen and oxygen and the very first spark or flame in the world will have caused a HUGE explosion of burning hydrogen that will, in one go, have made all the water in the world and it’s still here today. So if anybody was to separate water back into its oxygen and hydrogen atoms (it’s very easy to do) the first spark or flame will make the hydrogen burn up, grab the oxygen and turn back into water.
To be completely honest though, I must admit I am telling a tiny white lie about the total amount of water in the world being exactly the same, so I had better explain.
For instance, every time we send a spacecraft into space it will have a tiny bit of water on board, which is now stuck up there in space. So to be exactly truthful, we have to say that the tinniest fraction of water is up there in space going round the world. There is even a tiny bit on the moon and Mars where we have sent spacecraft. Even if the spacecraft was unmanned the people who made it will have breathed out whilst they were doing so and tiny particles of water vapour from their breath will have been trapped inside when it was sent into space. However, as this is such a small bit of water, I’m not going to worry about it.
Unfortunately, there is yet one more thing to think about just to be totally honest. If we think of water as meaning something that when purified, we could drink, then we have to consider that when we make concrete it starts out very wet and then it dries out as the water evaporate. BUT – a tiny bit of water does remain locked up inside. So if you are thinking about drinking water then there is less (even though it’s still here) because every city in the word has an awful lot of concrete in it. I don’t know about you but, if I’m thirsty, I don’t pick a lump of concrete and suck it like an ice-lolly.
Now the next step.
I want you to imagine the biggest lorry or articulated truck you can picture. Then think of five of them. All together they will weigh about 230,000 kg. Now ask yourself, “How could I get that weight of water to hang in the air?” The answer is, “Form a cloud”. Please remember, if it was a large thunder storm cloud (cumulonimbus) the weight of water would be many thousands of times more than that.
Now here’s the bit that a lot of people don’t think about.
I want you to consider a very muddy puddle. You probably know one that’s near your house every time it rains. When the sun comes out it evaporates and disappears so we know the water from millions of muddy puddles all over the world has done that.
Now think of standing in the rain and ask yourself this, “Where is the mud from all those puddles? Why isn’t it falling out of the sky along with the rain?” If you have ever stood outside in the middle of a warm, summer storm looking upwards with your mouth open and tasted the rain, you might have asked yourself, “Why doesn’t it taste of mud?”
The fact it does not, is the miracle of this wonderful process called evaporation.
As the tiny parts of water rise up into the cloud it is pure water only and all the mud or dirt is left behind. In fact we are incredibly lucky because Nature has given us the most perfect filtering system for providing clean, fresh water it is possible to have.
So let’s think about this a bit more and move on to the “Ughh!” moment.
Try and imagine a summer day and a dog having a wee up against a tree. In just a few minutes in the sun it has all dried up. The water from that dog’s wee has evaporated into the air and is starting to form a tiny cloud. That cloud will float about and meet other bits of water so that eventually the water will become too heavy. So now it will rain down and that could easily be straight into our town’s reservoir. In fact it’s possible for you to turn on your tap and drink that same bit of water the next day!
Let’s make it worse and think about a dog, let’s call him Bonzo, doing a poo somewhere right at this moment.
Here is a picture of Bonzo ruining a holiday photograph.
After a couple of hours of sun, Bonzo’s poo will have dried up before the tide has come in. So now we know it is possible you will drink that dog poo water tomorrow.
I expect, now you’re thinking how glad you are that when water evaporates it purifies it at the same time.
It’s important that we realise The Water Cycle is exactly just that, billions of tonnes of water going round and round in the world evaporating, gathering into clouds and eventually raining down and each time the water has been purified for us.
I still find it amazing. For instance, here is a photo of Mabel with her son Marmaduke.
What I find amazing is this. Mabel could do a big poo in Australia which will have dried out in about an hour. That water vapour will have risen into the air and met other tiny bits of water. They will all, over time, form a small cloud, which will blow round the world getting bigger and bigger. It is then quite possible that cloud will rain down on our reservoir and one of you could be drinking evaporated kangaroo poo water tomorrow.
So, next time you go to the tap to fill the kettle, just think about what you are pouring into it. It is possible that you have just used the same water that next door’s cat left on your garden when it had a wee two days ago OR it might be from a baboon’s poo in Africa OR perhaps Henry VIII’s cat 500 years ago. We have no way of telling.
HENRY VIII’s Cat
BUT – there’s more to consider and things become a bit more “Ughh!” now.
Scientists have been able to estimate just how much water there is in in the world and how many people have ever existed. They now believe that every drop of water in the world has been drunk at least 6 times before you turn on the tap and pour it into a glass for your own drink. So 6 other people have already passed it on as a big wee. If you are thinking, “Yeeuuck!” remember that estimate doesn’t include trillions of animals that have also have drunk that water.
Now, let’s take another, “Ughh!” step in our thinking. Not quite The Water Cycle but interesting.
If you talk to the water companies they are very worried because there are so many people in the world compared to the past. In fact there are more people living in the world today than has ever lived in the history of Planet Earth. This means the water companies have got to get better and better at recycling water. For instance, think about London. There aren’t many big lakes or reservoirs there. So how do they manage to keep the tap water flowing?
Well, you’ve probably guessed it.
When you have a wee and flush the toilet, it will all go to a sewage farm and be filtered and strained. Not much later, let’s say the next day, somebody or perhaps even you, could be drinking the same water.
Perhaps you have heard somebody say, “Oh it’s good to get back home and have a cup of real tea that has a good taste. It’s never the same anywhere else”?
Well, that is particularly true of London and all the highly populated cities of the world, simply because they don’t have room for huge reservoirs in the middle of a city. So their water really does taste slightly different and now we know why. So, although they don’t like to talk about it, the water companies do a brilliant job of getting the water back to us very quickly.
If you live in a city you’ve probably noticed!
To finish, as much as we might think, “Yeuuck,” we should take a couple of minutes to say a quiet, “Thank You” to Nature for constantly providing us with clean water, wherever it came from.