Zusammenfassung Since the discovery of a cold molecular component of the interstellar medium in the 1970s, it has been realized that most of the dark clouds are actually molecular clouds, consisting mainly of molecular hydrogen and some amount of dust and other molecules. Nowadays, molecular clouds are recognized as places of star-formation in the Milky Way and other galaxies. Therefore, studie...

In 1900 Lord Kelvin identified two problems for 19th century physics, "clouds" as he puts it: the relative motion of ether with respect to massive objects, and Maxwell-Boltzmann's theorem on equipartition energy. These issues were eventually solved by theory special relativity quantum mechanics. modern quotations, content Kelvin's lecture is almost always distorted misrepresented. For example, ...