The science bit…

Evaporation and photons

It was quite warm when I took this photo, in fact very warm in the car. I walked around the lake taking photos and it was cooler with a nice breeze. So to my first question; is the water in the lake, warm or cold?

Let’s think about the science. If you have a hot cup of tea or coffee, how would you cool it? You blow on it and that blows away the vapour over the surface of the liquid allowing more vapour to form and cooling your drink. The breeze was cooling the lake in the same way and so the answer to the question was the water would be cool! Why was it hot in the car? The sun was shining through the windows, photons entered the car and then bounced around making the car hot. Look at you neighbours windows, they appear to be black, light (photons) goes in, but doesn’t come out. This is the greenhouse effect, light goes into a greenhouse and bounces around making it warmer than outside.

The evaporating sea

When the sun shines on the sea, that evaporates too and the vapour forms into clouds. It cools the sea in the same way and so it’s self regulating to a certain extent, the hotter it is the more evaporation and the greater the cooling effect. This is an extremely smart system; this is nature… Heated air like heated water rises and as it does so it leaves behind nothing; a vacuum. Well alright a partial vacuum, which is constantly filled with more air and this causes the wind or makes the breeze. This movement of air tends to be in a circular form, with air rising in the deserts and eventually ending up at the polar ice caps. The problem is, it gets colder along the way and arrives very cold; but not cold enough. That’s why the polar ice caps are melting.

Thawing food

If you take food from the freezer and put it in the fridge at 5C, it will take 24 hours to thaw; but it will thaw. The temperature in the fridge is only a few degrees higher than the frozen food, but that’s enough. It’s the same with the polar ice caps, if the air is just a few degrees warmer, they will melt and they are melting.

Disappearing wind

So we know that it’s an air movement cause by air rising with heat that causes the wind and the wind carries clouds and that causes it to rain. If there was less movement of air we would see less rain and droughts in parts of the world. We have seen that because it is now a few degrees warmer than it was. You might say that it’s even windier now, that’s true, some of the time. Some places are colder now and we get storms, hurricanes and tornadoes. The wind is very unpredictable, the smart, self regulating system, we call nature isn’t coping. The causes are deforestation, forests tend to have a cooling effect as water evaporates off them. We have also been heating the Earth since the beginning of the industrial revolution and we are heating it more now than at any time in the past. The whole world wants a car in the 21st century.

What will happen if we do nothing about climate change? I don’t think anyone knows for sure, but it doesn’t look good does it? The polar ice caps were made from fresh water that has now mixed with salt water; they can’t be re-frozen. This problem is something people should think about, if it doesn’t affect us, it will affect future generations.

You might like some of my other blogs, links to them are on the home page.

One last question:

If nature is self regulating and smart, did it happen by accident or was it designed that way?

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