Theodor Wulf (July 28, 1868 - June 19, 1946) was a German physicist and Jesuit priest who was one of the first experimenters to detect excess atmospheric radiation.

Theodor Wulf became a Jesuit priest at the age of 20, before studying physics with Walther Nernst at the University of Göttingen. He taught physics at Valkenburg, a Jesuit University from 1904 to 1914 and 1918-1935. He designed and built an electrometer which could detect the presence of energetic charged particles (or electromagnetic waves). Since natural radiation sources on the ground were detected by his electrometer, he predicted that if he moved far enough away from those sources he would detect less radiation.

To test his hypothesis, in 1910 he compared the radiation at the bottom and the top of the Eiffel Tower. As he went up the tower, he found that rather than decreasing, the level of radiation actually increased. Energy was coming from outside the Earth's atmosphere and being detected by his device; this radiation was from cosmic rays. He published a paper in Physikalische Zeitschrift detailing the results of his four days of observation on the Eiffel Tower. His results were not initially accepted.

Publications

• Uber den Einfluss des Druckes auf die elektromotorische Kraft der Gaselektroden. Physikalische Zeitschrift Chemie
• About the radiation of high penetration capacity contained in the atmosphere. Physikalische Zeitschrift
• Einstein's relativity theory, 1921.
• Text book of physics, 1926.
• Electrostatic attempts with application of the universal electroscope, 1928.
• The oscillatory movement, 1931.
• The Thread Electrometers, 1933.
• The Components of the Body World, 1935.

See also

• Radiant energy

External links

• Biography (auf Deutsch)
• About the radiation of high penetration capacity contained in the atmosphere Physikalische Zeitschrift, 10th year, no. 5, pages 152-157
• About Observations of the Penetration {through-going} Radiation During 7 Balloon Flights
• About the absorption of gamma rays in the atmosphere