When does water freeze?
The freezing point of water was not determined by any physicist, it was determined by nature. Because water is well known as a ubiquitous medium, it was used as an indicator for the thermometer used in Europe. Every child knows the temperature at which water starts to freeze, but hardly anyone knows the history of the thermometer.
When did people start measuring
- The advancing civilization made it necessary that universal Dimensions and weights spread. This made it possible to compare different goods and services with one another and to build up a trade with them. This already results in the basic rule for measuring and weighing: It is the comparison.
- However, in order to arrive at a scale for comparison, units of measurement had to be set up. From here the story of the thermometer, in which three physicists and / or astronomers were significantly involved: The French Reaumure, the Swede Celsius and the German Fahrenheit.
When water freezes it is 0 ° C
- Gradually, degrees according to Celsius became established in Europe. It is not known when this was completed. In 1947 the degree Celsius became the legal measure in Germany. It was the one that could be explained most popularly: the temperature from which water freezes is zero degrees, then Celsius divided the scale up to the boiling point into 100 °. At first he wanted to count the other way around.
- What was really revolutionary about the Celsius thermometer was the effort of its inventor to make this scale the global standard, which he succeeded whenever and in the end. Only in the USA and some other English-speaking countries is still measured by Fahrenheit.
- Fahrenheit based his scale on the lowest temperature measured in his hometown of Gdansk in the winter of 1708/09. He assumed that there could be no lower temperature, and therefore set the zero degree mark at this point.
- He wanted to avoid that a thermometer also has to show negative degrees. Today we know that the temperature in Gdańsk at that time was -17 ° C. The graduation according to Fahrenheit was then specified, water freezes according to "F" at 32 °.
- There are also other systems which, however, have not achieved any general significance or have special technical backgrounds - such as the Kelvin system. Would you like one specification in another convert, you will find corresponding tables on the Internet.
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