Is the Earth a 'closed' system (a cycle of rainfall and evaporation)? Do we lose water vapour from the atmosphere? Or can there really be more water in our ecosphere than there used to be, and if so, where does 'new' water come from? There are all valid questions. I decided to consult a scientist. He said:"There is roughly about the same amount of water on Earth now as there was in the Mesozoic period. All water that is breathed, drunk, and urinated by living things remains as part of the planet’s total water content.
The total amount is not exactly constant, as there are two fluxes of water between Earth and the rest of the solar system. There is a steady rain of water-bearing meteoroids hitting the planet, which slowly increases the amount of water. At the same time, molecules of water often dissociate in the upper atmosphere into hydrogen and oxygen due to ultraviolet light from the sun. Some of the hydrogen atoms have enough energy to escape from Earth’s gravitational field, and so are lost. This slowly decreases the amount of water.
In addition, tectonic plate subduction is constantly carrying water down into Earth’s mantle, and volcanoes are constantly spewing water out onto the surface again. The balance between these two processes can change considerably over time.
But all of these fluxes are small compared to the total amount of water on Earth, and two of them are in the opposite direction of the other two. So the overall change is insignificant, even when considered over long spans of geologic time."I thought you'd all like to know that, if you didn't already. Onwards (and downwards).I've blogged about water in various guises before. I don't mean solid, liquid or gas, though I've dome that too. I'm referring to blogs about the sea, or floods, or thunderstorms, or water as the essence of life (with mermaids in it) as linked here: Essence
On the lookout for a new angle I thought that this time I'd investigate how we as human beings have managed to harness the power of water falling in the shape of the water wheel, specifically the overshot variety as pictured.
an overshot water wheel in action
The flow of water is channelled to drop onto the wheel which has a series of cups around its circumference and the weight of water falling into the cups causes the wheel to rotate in a clockwise direction (as shown), with gearing converting the power of the rotational movement into something with a practical application - like the grinding of grain, the turning of a lathe or the generation of electricity.
how am overshot water wheel works
There used to be many thousands of working water wheels around the world from tomes BC until the arrival of mains electricity made most of them redundant, rusting relics of a pre-industrial era. But maybe in a post-industrial age, their waterfalling turn will come again. Who knows.Anyway, to close here's a new poem written just yesterday (on the Ides of March). Humouresque (though not to be sung), I hope it amuses in places, intrigues in others, provokes occasionally, but above all entertains. Let me know if it works for you. It's obviously capable of extension as well, so ideas are welcomed!Water FallsUnzip a cloudwater fallsPull on the chainwater fallsTorture a prisonerwater fallsFire alarm triggerswater fallsLucifer descendingAngel Falls
Grieve for a losswater fallsSing in the showerwater fallsEdge of the worldwater fallsCrocodile tearswater fallsIdes of March fearsCaesar Falls
Frozen pipes burstwater fallsIce-bucket challengewater fallsWeather for duckswater fallsDay at the raceswater fallsBecher's and Valentine'sHorseshoe Falls
Hose-piping flower bedswater falls Sat in the car-washwater fallsReservoir summerwater fallsUnder rolling thunderwater fallsOh shit SherlockReichenbach Falls
When the dam breakswater fallsCry for the moonwater fallsCrank up the Handelwater fallsMill on the Flosswater fallsMaids in the mistViagra Falls
Thanks for reading, S ;-) Email ThisBlogThis!Share to TwitterShare to Facebook
