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Fahrenheit scale

Usual temperature scale in the US. Temperatures are given in degrees Fahrenheit (°F); the scale is defined historically, by using as its zero point the lowest temperature measured in winter 1708/1709 in Danzig (today Gdansk, Poland, Daniel Gabriel Fahrenheit’s hometown), while 100 Fahrenheit is human body temperature.

Relation with the Celsius scale widely used in Europe: X degrees Fahrenheit are (X-32)*5/9 degrees Celsius, Y degrees Celsius are (Y*9/5) +32 degrees Fahrenheit.

Relation with the Kelvin scale widely used in science: X degrees Fahrenheit sind (X+459.67)*5/9 Kelvin, Y Kelvin are (Y*9/5)-459.67 degrees Fahrenheit.

Definitioner

Kelvin (Kelvin-Temperaturskala)

In der Physik übliche Temperaturskala, synonym: absolute Temperaturskala. Außerdem die Maßeinheit für Temperatur gemäß dem Internationalen Einheitensystem. Nullpunkt ist der absolute Nullpunkt; ein Temperaturunterschied von einem Kelvin (abgekürzt 1 K, manchmal auch "ein Grad Kelvin") ist dasselbe wie ein Unterschied von einem Grad Celsius, denn die beiden Skalen unterscheiden sich nur durch die Wahl des Nullpunkts: X Grad Celsius sind X plus 273,15 Kelvin, Y Kelvin sind Y minus 273,15 Grad Celsius. Beziehung zu der in den USA üblichen Fahrenheit-Skala: X Grad Fahrenheit sind (X+459,67)*5/9 Kelvin, Y Kelvin sind (Y*9/5)-459,67 Grad Fahrenheit.

temperature

In systems consisting of many particles, be they solid bodies, fluids or gases, the constitutents are in constant, chaotic motion: the atoms in a solid crystal oscillate a bit, the molecules of a gas are in rapid, disordered motion, and so on. The average energy with which each constitutent contributes to every part of the disorderly motion is the same, and it is called the temperature of the system. High average energy corresponds to high temperature - atoms vibrating wildly, gas molecules zipping around very fast -, low average energy to low temperature. In a slightly different context, certain mixtures of electromagnetic radiation can be assigned a temperature ("radiation temperature"), a single parameter that completely defines the basic properties of the radiation (more precisely, its spectrum). It corresponds to the thermal radiation emitted by a hot body with precisely that temperature. In physics, temperature is measured in Kelvin, in everyday life, depending on the country, in Fahrenheit or Celsius.

point

Elementary "building block" of geometrical entities such as surfaces or more general spaces. For instance, a surface is the set of all its points, of all possible locations on the surface, and all geometrical objects in that surface are defined by the points that belong to them - for instance, a line on the surface is the set of (infinitely many) points.

Celsius

Most European countries use the Celsius temperature scale in everyday life. Temperatures are given in "degrees Celsius" (abbreviated as °C). By definition, the zero point of this scale (0°C) is the melting point of water, while the temperature 100°C corresponds to its boiling point (both parts of the definition assume the same standard value for air pressure). Relation to the Fahrenheit scale: X degrees Celsius correspond to (9/5 times X) +32 Fahrenheit, Y Fahrenheit are (Y-32)*5/9 degrees Celsius. Relation to the Kelvin temperature scale used in physics: X degree Celsius are X plus 273.15 Kelvin, Y Kelvin are Y minus 273.15 degrees Celsius. In particular, differences in temperature are the same in Kelvin and in degrees Celsius; the only difference between the two scales is their choice of zero point.

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Fahrenheit scale

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