Alexander Dahl

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Alexander Dahl (born November 29, 1892 in Barmen , today part of Wuppertal ; † December 15, 1978 in Wuppertal) was a manufacturer, author and balloonist . Due to his balloon flight in August 1933, he is considered a pioneer in aviation .

Life

Dahl was trained as a reserve lieutenant in the First World War to be a tethered balloon observer and free balloon pilot. After the First World War, he joined his father's leather factory as a junior manager, which he took over in 1934. His main interests, however, were aviation, high-frequency technology and balloon flights. 1941-1945 he took part in the Second World War as Major dR in the Air Force and speaker in the Luftnachrichten-Troop (Luftgau VI), where he was able to make a contribution to the high-frequency war (see publications). After the company closed in 1958, he became a consultant at the German Society for Positioning and Navigation (DGON) in Düsseldorf until he left in 1965.

Services

On August 31, 1933, Dahl started in the open basket of the Bartsch von Sigsfeld free balloon on a scientific high-altitude flight to measure sun rays and other meteorologically relevant phenomena in the tropopause area . Alexander Dahl was the company's pilot and technical director. The scientific management of the expedition was Paul Alfons Galbas (1888–1933), the head of the Essen - Mülheim flight weather station . The third participant was Walter Popp from Essen. The balloon was specially built as an altitude balloon with 9800 m³ for hydrogen filling.

It was not intended to surpass the existing world altitude record of 10,800 m, which has been held by Arthur Berson and Reinhard Süring since 1901 . For this reason there was no prior official registration. When, on August 31, 1933, the advance into the stratosphere with a height of 11,300 m was actually reached, there was no official recognition. Nevertheless, a similar height has not yet been reached in the open balloon basket to this day. A later attempt to record a record by another German crew with the same balloon was fatal.

Dahl's photo from August 31, 1933. The curvature of the horizon is likely to be largely due to an imaging error.

Aerial view from the high altitude balloon

Dahl took the adjacent photo on August 31, 1933 at 2:00 p.m. from the open basket of the free balloon at a height of 11,300 m. In Dahl's environment, it is claimed that this is the first recording of the earth's curvature . However, modern investigations cannot understand such a strong curvature of the horizon at the height mentioned and make barrel-shaped distortion responsible for it, an aberration of the lens that increases towards the edge of the image. It is generally assumed that the curvature of the earth was first seen by Auguste Piccard and Paul Kipfer on May 27, 1931 at an altitude of 15,787 m and was first photographed on November 11, 1935 by Albert W. Stevens and Orville A. Anderson at an altitude of 22,066 m.

  • Photo taken on August 31, 1933
  • Infrared plate recording with ruby ​​filter
  • Cold-resistant receiving chamber
  • Lens: 1: 4.5 137 mm 1/25 sec., Central shutter
  • Location: 5 km northeast of Bonn, looking north / east
  • Horizon: approx. 430 km
  • Horizon length: approx. 380 km
  • Height of the cloud cover: approx. 2,000 m
  • Temperature: −52 ° C

Fonts

  • Alexander Dahl: Boomerang, a contribution to high frequency warfare, military science reports, Volume 13, JFLehmanns Verlag, 1973 ISBN 3-469-00465-X .
  • Mj. d. R. Dahl: German countermeasures against fdl. Radio navigation 1942-45 , AFO special library , No. 1029, 1960.
  • Alexander Dahl: In the open free balloon basket into the stratosphere , starting and flying, Volume 5, Ger. Stuttgart publishing house.
  • Alexander Dahl: Radar technology for more than 60 years , DGON publisher, issue II / 1964.

literature

  • Alfred Eckert: In the sky without a motor , Die Brigg publishing house, Augsburg 1975 (The first scientific achievements) Page 116–117, ISBN 3-87101-087-1 .

Notes and individual references

  1. ↑ named after the airship designer Hans Bartsch von Sigsfeld , who had an accident in a balloon flight in 1902
  2. ↑ a b cf. David K. Lynch: Visually discerning the curvature of the Earth . In: Applied Optics . tape 47 , no. 34 , December 2008, p. H39–43 (English, thulescientific.com [PDF; 4.4 MB ; accessed on August 17, 2018]).
  3. ^ History of the Essen Ballonfahrtverein , accessed on September 24, 2018

Web links

personal data
SURNAME Dahl, Alexander
BRIEF DESCRIPTION German manufacturer, author and balloonist
DATE OF BIRTH November 29, 1892
PLACE OF BIRTH Wuppertal
DATE OF DEATH December 15, 1978
Place of death Wuppertal