Wind is fun. (All right, who giggled? No, not that kind of wind.)
We’re surrounded by air all the time, and apart from the fact that we keep on breathing, we don’t pay it much attention. Unless it’s moving. Wind can feel like we’re being hit in the guts with a wheelie bin – it has power, it has menace, it has character. And yet it’s just a bunch of tiny gas molecules – mostly nitrogen and oxygen – moving from one place to another.
They move from places where there are more air molecules to places where there are fewer air molecules. That’s areas of high pressure to areas of low pressure. A great example can be felt at the beach. In the morning, the land warms up quicker than the sea. The warm air above the land rises, so there are fewer air molecules above the land, and the cooler air from above the sea rushes in to fill the gap. You feel the wind blowing from the sea towards the land in the morning. By the end of the day, the sea has warmed up a bit too, and the water takes much longer to cool down than the land. So the air above the sea is now rising more than the cooler air above the land, and air rushes from the land towards the sea instead. Check it out next time you’re at the coast – is it morning or evening and which way is the wind blowing?
We’re making ‘wind catchers’ this pre-school day to spin and swirl and sparkle in the wind. They show you when the wind is blowing, but mostly they’re just nice to watch, and slightly mesmerising. They lead me to think about how we use the wind. Wind power conjures up images of dramatic white turbines across barren hillsides, but it’s nothing new. The remains of stone or brick towers, missing their wooden hats and sets of cloth-covered sails, are scattered across our landscape. And that’s nothing compared to the water pumping network of windmills in the Netherlands keeping the water level below the farmland for 200 years. The oldest Dutch windmills are more than 500 years old. But long, long before that humans were using wind power to travel the world. In fact the earliest evidence of sailing comes from more than 6,000 years ago.
Most of the time, we ignore the wind, unless it’s throwing things in our faces or knocking us off our feet. But it’s a tribute to human innovation that we can make use of just about anything, even if it’s just a bit of air gliding aimlessly over the surface of the earth.
Come along and play this pre-school day! Tuesday 23 May, 9.30am – 3.00pm