Carl Wilhelm Wirtz

Who was Carl Wilhelm Wirtz?

Carl Wilhelm Wirtz was an astronomer who spent his time between Germany and the Observatory of Strasbourg.

As already Vesto Slipher in 1912, Wirtz in 1918 observed a systematic redshift of nebulae, which was difficult to interpret in terms of a cosmological model in which the Universe is filled more or less uniformly with stars and nebulae. Wirtz additionally used the equivalent in German of K correction. The term continues to be used in present-day observational cosmology, but Wirtz's observational evidence that the Universe is expanding is not often mentioned. He wrote:

It is remarkable, that our system of fixed stars shall have such a very strong displacement of 820 km/s, and equally strange is the interpretation of the systematic constant k = + 656 km. If we ascribe a verbatim interpretation to this value, then this means that the system of spiral nebulae is drifting apart by a velocity of 656 km with respect to the momentary location of the solar system as the center.