After a conception and reconstruction phase of several years, the Victor Franz Hess observatory on the Hafelekar mountain above Innsbruck was officially presented to the public on 29th September 2022. On this occasion, the European Physical Society awarded the station the distinction of "EPS Historic Site".

The research site was renovated by the University of Innsbruck with the support of the City of Innsbruck and the “Nordkettenbahnen”, the railway and cable cars which make the hut easily accessible, and transformed into a new attraction high above the roofs of the city, at more than 2,300 metres above sea level. The new concept offers visitors the opportunity to get to know the person Victor Franz Hess and his research as well as the phenomenon of cosmic radiation through multimedia presentations. During the opening ceremony, the EPS, represented by Past President Rüdiger Voss, awarded the site the distinction of an EPS Historic Site, the third of its kind in Austria and the first outside Vienna. "Victor Franz Hess did amazing things for science and the University of Innsbruck is very proud of its former professor. Today, members of our physics institutes are continuing this successful tradition with their groundbreaking research on quantum physics, ion physics and astroparticle physics. The newly designed observatory on the Hafelekar gives all visitors an insight into the pioneering work of Victor Franz Hess and the fascinating world of physics. We invite all those interested to take advantage of this opportunity and combine the joy of nature with learning about the history of the natural sciences," said Tilmann Märk, Rector of the University of Innsbruck and himself a distinguished physicist.

Rüdiger Voss, former President of the European Physical Society (right), unveils the EPS Historic Site Victor Franz Hess observatory at Hafelekar
together with Rector Tilmann Märk (middle) and Mayor Georg Willi (left) - image: EPS/Gina Gunaratnam

Experience research

With the redesign of this unique research site, the exterior of the hut was restored to its historical condition. To this end, the roof was renewed and the entire building was covered with wooden shingles. But it was also a matter of making the research work and the person Victor Franz Hess easy and understandable for all visitors to the Hafelekar and making it possible to experience it from the outside all year round. In a video installation, visitors can now get to know the researcher Hess as well as immerse themselves in the world of cosmic rays. Inside the hut, a showroom has been set up for expert visitors, in which the stages of Victor Franz Hess's life as a researcher are documented.

Rays from outer space

As early as 1912, Victor Franz Hess discovered cosmic rays during daring balloon flights. For a long time, he was searching for a place at high altitude that was suitable for the continuous measurement of the high-energy rays. He found what he was looking for in the construction hut of the Nordkettenbahn on the Hafelekar. In the 1930s, there was a great deal of activity there. After Hess received the Nobel Prize for Physics in 1936, the most renowned scientists of the time visited the observatory. This place also helped other researchers to make groundbreaking discoveries. On photographic plates exposed here, Marietta Blau and Hertha Wambacher observed for the first time in 1937 how a particle of the cosmic rays shattered an atomic nucleus. In the 1960s and 1970s, a neutron monitor and muon detectors were installed. This enabled the researchers to measure two types of particles contained in the cosmic rays individually and to gain important insights.

Now, the Victor Franz Hess observatory on the Hafelekar is not only a historical site, but still a place of research. Unlike in the past, however, the results of the corresponding detectors are no longer analysed on site: Today, the measurement data is sent directly and digitally to the different research groups.

The Victor Franz Hess observatory was awarded the EPS Historic Site designation on 29th October 2022 - image: Eva Fessler

Original press release in German: https://www.uibk.ac.at/de/newsroom/2022/sanierte-victor-franz-hess-messstation-eroffnet/
translated with DeepL and validated by the University of Innsbruck.