Karl Killian

Karl Killian (* 1903 ; † 1991 ) was an Austrian geodesist and inventor .

Life

Killian worked as a private scholar in almost all areas of surveying , geometry and higher geodesy , but also on subjects of applied and theoretical geophysics , mathematics and natural philosophy .

Around 1970 he was awarded the title of professor . He never had a job at a university , but he did exchange ideas with university lecturers .

In recognition of his scientific life's work, the Austrian Commission for International Earth Surveying (ÖKIE) awarded him the Friedrich Hopfner Medal in 1978 .

From the abundance of Killian's work and suggestions, three topics or incidents that are typical for his way of thinking should be selected:

Three themes

Surveying practice

When Karl Killian was working on a larger surveying job in the Danube floodplains around 1970 , the gelsen (mosquitos) were the biggest problem , as is usual there . Whenever the geodesic on the theodolite's eyepiece - at that time still without automatic support - had to search for a sight or an escape pole in the dense jungle for minutes , it would be the victim of hundreds of stitches per minute. Usual defense measures such as fleeing, waving, gel cream were of little use (the latter strained eyes and nose). Only violent movement helped. But Killian invented the gel umbrella: a specially mounted umbrella that is opened and closed every few seconds using a foot pedal.

geometry

" Dangerous places " when cutting backwards : As is known in specialist circles, this method of determining the position is imprecise if the appropriate targets (mostly church towers ) and your own survey point are approximately on a circle. What has been bothering the practical geometer for around 200 years ( Pothenot's problem with hundreds of specialist publications and tips) prompted Killian to find an original way out: the analysis of the 3D reverse section.

The problem changes when the "3 dangerous points" are at different sea levels. Later, Killian's idea was even extended to the evaluation of satellite measurements (optically or with satellite cameras ) and enabled better planning of Europe-wide measurement campaigns (see also Stellar triangulation ).

geophysics

When plate tectonics became generally accepted in the 1980s , Killian, like others, had great doubts as to where the immense forces that shift entire continents should come from. He suspected that it could be a question of reduced friction between the layers in the interior of the earth - keyword sliding friction . Long he tinkering of suitable mechanical and physical models, materials and theories until it got out that two smooth wooden surfaces underground rock - parameters come closest.

Fortunately, he had submitted his idea to two geodesy professors beforehand. One of them, Kurt Bretterbauer , remembered it years later and began to construct such a wooden model with a mechanic. When it worked satisfactorily after a few weeks, Killian's intuition proved to be completely correct: from a certain, slight incline of the wooden " Moho surface " (separating layer between the earth 's crust and the earth 's mantle ), a tiny force was enough to make the upper layer slide evenly. The applicable angle of inclination (after geomechanical conversion) was plausible from the point of view of applied geology .

literature

• CV and speeches. In: Austrian Journal for Measurement and Photogrammetry (ÖZfVuPh). 66th year (1978), pp. 105-116.
• Thomas Wunderlich (Ed.): In memory of Karl Killian: "Engineer" and "Geodät" 1903–1991. (=  Geoscientific Communications . No. 47 ). Study of surveying, Vienna University of Technology, Vienna 1998, urn : nbn: at: at-ubtuw: 3-1046 (117 pages).

Web links

• Austrian Geodetic Commission, award of the Friedrich Hopfner Medal, Vienna University of Technology on oegk-geodesy.at