Vakuum - vom Barometer zur Ultrahochvakuum-Apparatur
- Brötchen-und-Borussia

Air pressure often goes unnoticed in everyday life. But when we create a vacuum, i.e. an airless space, the air pressure surrounding us becomes noticeable. Many things change in a vacuum - for example, the propagation of sound or the boiling of liquids.
We go even further away from everyday reality when we consider the so-called "ultra-high vacuum". Here, the pressure is a factor of 1013 (10,000,000,000) times smaller than in our everyday life. Such a vacuum is costly to create, but it is very important for many experiments in physics and also in industry - for example, in the investigation of surfaces or in the semiconductor industry.
In this lecture, many surprising connections and effects in a vacuum will be presented. Live experiments will be shown, which of course can be followed particularly well when attending in the lecture hall.
![3D visualisation of human neuronal tissue reconstructed by multi-scale X-ray phase contrast tomography. Neuronal cell nuclei are shown in yellow for the granule neurons in the dentate gyrus region of the hippocampus. Blood vessels are shown in red. By changing the X-ray optical magnification in the multi-scale recordings, one can zoom into regions-of-interest (red ovals). In these scans the resolution is high enough to resolve sub-structures of the nucleus, associated with different DNA packing regimes. Adapted from [6]](/storages/physik/_processed_/e/4/csm_Kolloquium_Salditt_0e30a3f090.png)





