Sunsets

Have you ever seen a sunset?

At this time of the year it happens quite early, sometimes even before the teddy bears have had their tea! But it does mean that they are able to watch it happen. And they take lots of photos to prove it.

Sometimes it isn't really much of a picture because the day has been cloudy or rainy and you can hardly see the sun set. But if it's been a lovely clear, sunny day, it can be really spectacular.

The sky gradually changes colour from blue to yellow to orange to a fiery red with the big red ball of the sun steadily falling towards the horizon. Look at the photos the bears were able to take - aren't they gorgeous?

But why does this happen? Here's the science-y bit:

Put simply, light travels from the sun and through the earth's atmosphere (that's all the air above us) in invisible waves. Light that looks white to us is actually made up of many different colours of differing wavelengths (that's the length that the light has travelled). For example, blue has a short wavelength, while red has a longer wavelength.

At sunset (and also at sunrise), the sun is very low in the sky, which means that the sunlight has travelled further. Any blue light therefore doesn't reach us very well, but orange and red lights do.

And there is a very old, well-known weather saying "Red sky at night, shepherd's delight. Red sky in the morning, shepherd's warning." A colourful saying, but is it true? Actually, here in the United Kingdom, it generally is.

Our weather normally comes from the west, which is where the sun sets. And if you can see a really red sunset, it means there is high pressure (which normally means dry and pleasant weather) moving in from the west, and of course shepherds are delighted about that because it means their flocks of sheep will be dry and warm.

The "red sky in the morning" part of the saying being a warning is also generally true, because it means that the high pressure has already moved east, meaning the good weather has already passed, most likely making way for a wet and windy day. Something the shepherds (and their sheep!) won't like.

Anyway, if you happen to still be awake when the sun is going down, look towards the West, where the sun sets, and see the colourful show, and even take some photos yourself if you can so that you can look at them on dark, rainy days to cheer yourself up. Try not to stare directly at any sunset for a very long time though, especially through your camera.

The teddy bears would like to try and see the sun rise one day, but they're usually still fast asleep! Perhaps they can try in a couple of months when it doesn't rise until much later (perhaps they'll be up then!)