All substances on Earth, be it a solid, liquid or gas, contract when cooled. When any liquid freezes, its hardened fractions, as denser and heavier, sink and sink to the bottom. Anything other than water. Water is another matter automatic palletizer machine entirely.
Water vapor, cooling, like all gases, decreases in volume. A boiling liquid, when cooled, initially behaves like all normal liquids. But as soon as its temperature drops from + 100 ° C to + 4 ° C, it immediately changes its behavior to the diametrically opposite: from + 4 ° C and until it freezes completely, the water expands, increases in volume. The volume of ice is 1/11 more than the volume occupied by water before freezing. This expansion can be fatal to water pipes if water is left in them in the cold. Steel walls will burst with ease, as if they were not made of steel but made of paper.
Water is the only liquid on Earth that does not sink in a frozen state. Now imagine what would happen if the water suddenly changed its “abnormality”. Lakes, rivers, seas and oceans would begin to freeze from bottom to surface in winter. Over the winter, they would have turned into giant blocks of ice that most likely would not have had time to melt during the summer months. All life in the seas, rivers, lakes would be frozen. Freezing of water bodies to the very bottom would sharply reduce the amount of evaporating water, and with it the amount of heat released into the atmosphere. Precipitation would stop – rain and snow. A dry ice cold from the poles would move towards the equator. And hardly the sun would have been able to defend even a narrow strip of earth suitable for existence for humanity. Most likely, our planet would turn into a continuous lifeless glacier …
Heat accumulator
No substance on Earth absorbs as much heat as water. The heat capacity of water is 10 times the heat capacity of steel and 30 times the heat capacity of mercury.
To convert 1 kg of water into steam, 2260 kJ of heat is needed, more than for any other substance. Hang an empty kettle over a fire and it will glow red-hot in a few minutes. Now fill it with water. Will the water boil soon? “If you look at the Kettle,” says an English proverb, “it never boils.” But the same 2260 kJ of steam is released into the environment, condensing into water. In all of its three states, water is an excellent heat transfer agent; a circumstance that not only created conditions on Earth suitable for life, but also life itself.
Gas absorber
Remember, water is a reliable filter for the atmosphere. No liquid absorbs gases as greedily as water. But, under certain conditions, it easily and voluntarily parted with the absorbed gases.
Pour tap water into a glass and place it on the table. Soon you will see how the walls of the glass will be covered with a scattering of small bubbles – a part of the air dissolved in it has left the water. Water is under pressure in the water pipe, and by pouring it into a glass, you relieve it of this pressure.
The lower the ambient pressure or the hotter the water itself, the more intensively the air dissolved in it will be released – a property of water that has caused and continues to cause major troubles for hydroelectric builders.
Metal eater
1894 … The famous English shipbuilders launched the destroyer “Daring”. The ship was equipped with super-powerful steam engines at that time. Designers rub their hands in anticipation of the triumph of their brainchild. Still would! At such and such a speed of such huge screws, as calculations show, “Daring” will amaze the world with the speed of its movement. Sea trials began. The Daring machines are running at full capacity. Over the stern of the ship, surf breakers rose from the super screws. And the speed of the ship … is far from the calculated one. The inexplicable happens – the vessel is shaken by vibration. It seems that it is about to fall apart. The speed drops continuously. Already the Daring is crawling like an old sailing shoe. The tests were stopped, the destroyer was taken to the dock. Imagine the amazement of the shipbuilders when, instead of screws, they found shapeless pieces of metal. This is how technology first encountered another property of water – the property of “devouring” metal.
In 1907 the world famous ocean liners Mauritania and Lusitania began to lose speed. Upon examination, pits with a depth of 6-8 cm were found on the propellers of both ships. The propellers had to be changed every two months, as they lost their streamlined shape – the water “devoured” them. It cost the firm $ 70,000 to replace each screw. Ultimately, the floating “cities” were put on hold.
In the First World War in the German navy, the screws on the torpedo boats did not work for more than a week, then they were changed. The newly installed screws began to lose their shape after 24 hours of operation.
In the United States, a hydroelectric station was erected on one of the rivers. The water was raised to the design level and allowed to flow to the turbines. There was a crash, as if land mines had begun to explode in the bowels of the station. Frightened engineers rushed to cut off the water. There were no traces of the land mines allegedly planted under the station. But on the walls of the water supply tunnels here and there were.
Pieces of concrete were torn out – an incomprehensible reason enraged the stream of water. Until now, hydro-builders have never seen anything like it.
Thus, water became an unexpected and insurmountable barrier on the way to increasing the speed of sea vessels, rotating turbines, pumps, and increasing the flow rate in ordinary pipes. It has become the number one enemy of hydraulic engineering.