Wärmeausdehnung

Wärmeausdehnung refers to the phenomenon where matter generally expands when its temperature increases. This expansion occurs because the average kinetic energy of the particles within a substance increases with temperature, causing them to vibrate more vigorously and move further apart. Conversely, most substances contract when cooled. The extent of this expansion or contraction varies depending on the material and the temperature change.

For solids, this expansion can be observed in everyday situations, such as bridges having expansion joints to prevent buckling due to temperature fluctuations. Liquids also expand when heated, which is the principle behind common thermometers. As the liquid inside the thermometer heats up, it expands and rises in the narrow tube. Gases exhibit a much more pronounced expansion compared to solids and liquids for the same temperature increase. This behavior is described by the ideal gas law. The mathematical description of thermal expansion often involves a coefficient of thermal expansion, a material property that quantifies how much a substance expands per degree Celsius or Kelvin of temperature change. This property is crucial in engineering and material science to account for dimensional changes in structures and components under varying temperatures.