Physics in the monastery: Stift Kremsmünster

At first look it seems unusual to look for physical science in a monastery. But in fact the oldest and longest continuous existing series of meteorological measurements with air pressure and temperature, which continues until today, in Austria has not been started in one of the Universities, but from monks in a monastery. The same is btw. true also for observations of the Sun and in particular of sunspots. In particular, the Austrian imperial and royal maps that were created before the standardization on to the Greenwich meridian, had a reference point within Austria. For practical reasons this had to be a place where also astronomical observations were possible, in order to be able to determine the local noon and therefore also a reference point in time besides the spatial reference. All this was possible in Austria already in 1762 at the Kremsmünster monastery. Their archives do have a high value not only for the research of the long-term variability of the Sun, but also for long-term changes in the climate over hundreds of years. This is the reason why a group from the Institute’s department of astro- and geophysics found it only logical to visit the monastery Kremsmünster.

With the Kremsmünster weather data one can reconstruct the impressive fact, that the local climate in upper Austria shows already a significant temperature rise of more than 2 °C in the yearly averages. Observations that are comparable with modern weather stations have started in Kremsmünster already in 1769. Observations of the Sun allowed us already to have detailed insights in the sunspot situation at the Sun in the 18^th century that lead to new scientific results. We could in particular correct some mistakes in the historic sunspot number record; see link to a paper with a contribution from Graz in the literature list below. In a similar way, reports of one-in-a-hundred-years events of solar eruptions found in the Austrian Journal for Meteorology helped us to understand better. In February 1872, for example, striking sunspots were observed and only a few days later observers as far in the south as Egypt reported well visible polar lights, which otherwise would only be visible in Finland or further North. To understand such extreme events better, will help us to prepare the modern society to solar eruptions that this modern society has not yet experienced, but that are already well documented in archives of the 18^th century.

Besides the purely scientific aspects, this excursion was of course also interested in the astounding and numerous curiosities in the Physical Cabinet, which can be seen on public guided tours in the Mathematical Tower of the monastery. In its very beginning, physical science was often invented in order to entertain the high society and therefore also financed this way. But also the original historic library of the monastery was a special highlight for the group from Graz. In summary, this was a great excursion with best weather and a lot of fun, social experience, and interest for science.

Literature:

• Hayakawa et al. (2020): „Thaddäus Derfflinger's Sunspot Observations during 1802-1824: A Primary Reference to Understand the Dalton Minimum“
  in Astrophysical Journal 890/2, 98, DOI: 10.3847/1538-4357/ab65c9

• Hayakawa at al. (2023): „The Extreme Space Weather Event of 1872 February: Sunspots, Magnetic Disturbance, and Auroral Displays“
  in Astrophysical Journal 959/1, 23, DOI: 10.3847/1538-4357/acc6cc