Happy Earth Day to You

Four big thoughts to help you understand our planet

It is sometimes difficult to remember, especially at the moment, that we are part of something much bigger, so I've put together four things I think everyone should know and remember about the planet. This blog post is less about travelling the globe, and more about taking a moment to appreciate it.

---

Exotic Earth

Where ever you are today take a moment to go outside and find a patch of mud or grass - bear with me... Pick up a stick and give it a poke. Most of us walk or run on this ground everyday and pay little notice, but it's really rather remarkable. If you're feeling inquisitive why not pick up a handful and spread it out on a table for a closer look. What did you find? Some non-descript bits, a stone, some wood fibres maybe.

But what can't you see? What story does it tell?

Perhaps there are tiny grains of sand from the Sahara Desert, blown 1000s of kilometres all the way from Africa...? go on, look closer.

A few times a year a strong wind will blow dust and sand up into the air with such force that it gets caught in the Earth's global air currents - these are the ones that move across continents high up in the atmosphere.

If its moving in the right direction (from the South, blowing North if you're in the UK) the clouds of dust and sand will eventually be suspended overhead. Then, when it rains - which happens a lot here - the red dust and sand falls from the sky caught up in the droplets. You'll sometimes see it as smudges on your car and windows.

Next time you notice this, don't be annoyed that you have to clean the car, be inspired - this dust has travelled a long way to get here, and it comes from a mysterious far off land where cheetah and wild dogs roam (isn't it exciting?). Its rich in nutrients and helps fertilise our own soil, helping us grow the crops we need to eat.

---

Gone with the Wind

Wind is the movement of air. We can feel it as it brushes past our skin. It's one of life's simple pleasures to go outside and feel the wind on your face. Stick your head out of the window, what do you feel? A gentle breeze, big gusts, or is it completely still?

When you feel the air brush past your skin, do you ever stop for a moment and think about where in the world this wind comes from? Well we know from our Saharan sandstorm that wind can carry huge clouds of dust and sand across continents, and you might have heard the weather reader say that we're catching the tail end of a hurricane happening on the other side of the planet. So, how is it connected?

The answer is all to do with pressure and I have two simple experiments to explain how it works.

1. Put your hand in front of your mouth and blow onto it. Notice how it feels. Now, breath in as far as you can. The deepest breathe you've taken all day. Once you're there take in a bit more. hold it... Now the tight feeling you have in your chest is a build up of air pressure. That's Billions of air particles bunched up tight in your lungs wanting to escape. Now put your hand in front of your mouth and breathe out. Did you notice a difference? The high-pressure big breath should feel stronger than the lower pressure normal breath. Try again if you're not sure.

Wind is the same! Air moves from high pressure to low pressure areas, and as it moves we can feel it. You created your own wind by building up the pressure in your lungs. So how does this happen on Earth?

It's all to do with temperature.

2. Put the kettle on or pop some water in a pan, put a lid on and wait for it to heat up. Once hot you'll notice steam coming out of the kettle, or perhaps the lid of the pan moves. The heat, like your breath in, is increasing the pressure on the inside of the pan. The walls and lid of the pan will be experiencing the tightness you felt in your chest. And you can see the particles escaping into the room - don't try and feel it with your hand because it hot...!

As the sun heats up the Earth each day, different areas of pressure build, and the air moves between these areas as wind. The hotter the area, the higher the pressure, and the more extreme the wind. I'll let you connect the dots with global warming and more extreme weather!

---

In Cold Water

Long have explorers crossed the seas to explore our planet, driven by winds and ocean currents. We learnt all about the global air currents, but what about water? How are our oceans connected, and how do they effect one another?

Again, it's a lot to do with temperature.

But this time its about the cold, rather than the hot. A simple experiment you can try at home if you have a bit of food colouring in your kitchen - if not, try with a tea bag (it's not as clear but it still works).

Convection currents experiment:

1. Boil the kettle and pour yourself a mug of hot water (or use the water you already heated in the wind experiment).

2. Fill a clear container with water - if you don't have one see if someone is recycling a large clear plastic bottle and cut an opening down one side so you have a plastic bottle boat full of water (it can still be recycled at the end).

3. Gently pour your food colouring or place your tea bag in the center point of your container.

4. Hold the container over the hot mug so the heat lines up with the colouring.

- Now watch -

You should see the dye rise up with the heat, and fall at the edges where it's cooler.

An alternative experiment is to make an ice-cube of dye and put it in a tall glass. You should see the cold dye sinking in the room temperature water.

Now, let's think bigger.

The Arctic and the Antarctic are the Earth's ice cubes. They are the cool areas that drive this amazing mechanism around the globe. The movement of water carries with it salt and food from one area to another on a huge scale. It basically drives all ocean life on our planet! This is why keeping the polar regions frozen is SO very important for everyone on the planet.

---

Floating on Fire

If you thought the air and oceans were crazy, I have one final thought that should blow your mind like an exploding volcano. The Earth, with all the habitats, people, cultures, languages and countries, is at it's core a solid mass surrounded by hot firey molten rock and metal.

Perhaps, like me, you've been lucky enough to visit a volcano, and if not you might have seen a film of an eruption. This is a gateway allowing us to glimpse into the gargantuan forces at play deep beneath all of our feet. There is loads of science about these forces and mechanisms - much is still not known - but, what I'd like us to do today is simply take a moment to comprehend this idea as a whole. As a big picture.

This final demonstration in our Earth appreciation post is the most simple, but perhaps the most important. Grab an advacado, apple, orange or another fruit you happen to have and cut it in half. You might know this demonstration, but do it anyway... go on.

learning isn't always about finding out a new fact, but seeing a fact you knew from a different perspective. You might find you feel or think differently this time.

The peel of the fruit represents all of the land, sea and air we experience in our lives, while the delicious fleshy bit - the important bit - is the rest of our planet. Try and take a moment, see things from a different perspective. Truly try to comprehend this idea. Our planet is one place, one giant system with one core.

Everything is connected and today is Earth Day, a time to reflect, and show respect for our planet. We might be only a small part of this world, but small things can make a big difference.

---

Happy Earth Day!

- Make a wish for the future and work together to make it come true -