Many architects, engineers, medical doctors, and scientists made their homes and careers here in Berlin. Not only is evidence plain to see in buildings, memorial plaques, and sculptures, but by the final resting places of the renowned throughout the capital city.
In Schöneberg’s Alter St. Matthäus cemetery, I say “hello” to Kirchhoff, Kronecker, and Rubens; as well as Mitscherlich and the Brothers Grimm.
Leopold & Fanni Kronecker. In my training, I learned about the Kronecker delta function whose utility became more apparent in learning about mathematical physics: e.g., “how to write the identity matrix or tensor in a couple of terms.”
Gustav Robert Kirchhoff. I learned the Kirchhoff laws (or rules) of electrical circuits, and later, the Kirchhoff law of thermal radiation. He and Robert Bunsen created the spectroscope, and with the new spectroscopic examination of sunlight, discovered in 1861 the elements caesium and rubidium.
Heinrich & Marie Rubens. Thanks to Rubens’ measurements of infrared radiation, Max Planck was able to derive and write a new law of radiation, based on the discreteness (quantization) of energy. Ruben’s’ work extended the range to larger wavelengths (smaller frequencies) and helped set the new 20th-century “quantum mechanics” on solid experimental ground.
Eilhard Mitscherlich. I didn’t know about this until I searched his name. In 1819, the chemist studied various compounds with phosphorus and arsenic in the laboratory, and realized they crystallized similarly: thus began the study of crystallographic isomorphism.
Members of the Grimm family, including Brothers Grimm Jacob & Wilhelm. They collected fables and fairy tales of their time in the German language, many of which have been sanitized for popular consumption today.
The cemetery is free to enter, but opening times vary during the year; summer hours (May to August) are 8am to 8pm. The cemetery’s main entrance (shown here) is directly opposite the south entrance to S1 S-Bahn station Yorckstrasse.
I made all images above with an iPhone15 on 20 May 2025. This post composed within Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com.
Gerhard Mercator was a 16th-century geographer and cartographer whose techniques of the time revolutionized map-making. Named after him is the Mercator projection which he created for a world map in 1569. The Mercator is one of the most widely used projections to map the entire world.
Gerhard Mercator. Duisburg, Germany. I wanted to go and find out.
I purchased a new Deutschland-Ticket (DE-Ticket) for 58€ which allows for travel on all modes of city and regional transport. With the ticket “embedded” in the iOS app, it is a simple matter of displaying the ticket’s digital QR-code for the inevitable on-board fare inspection.
From Köln, I travelled first on one of the city’s trams from my hotel to the nearest train station Messe-Deutz, where I caught a RE regional-express train northbound to the central station in Duisburg (DU). Upon arrival, I got onto the city’s 901 tram for the short ride to the stop at Rathaus. All of this multimodal travel is included in the DE-Ticket, as well as my return to Köln.
Born in Flanders in 1512, Gerhard Mercator eventually moved to the vital imperial trade port of Duisburg in 1552, where he lived until his death in 1594. He was buried in Duisburg’s oldest house of worship, Salvatorkirche (Church of Our Saviour), located next to the Rathaus (city hall). Although bombing in World War 2 brought severe damage, the grave plate remained relatively intact, and subsequently repaired and restored. The epitaph is presently mounted inside on the church’s south wall to the right of the main altar.
I include additional images of the Mercatorbrunnen (Mercator memorial fountain) in front of the Rathaus, and the sculpture “Hommage À Mercator” (homage to Mercator) about 0.5 km walk to the east and near the location where the house in which Mercator lived is now an archaeological site.
In the Mercator projection shown below, the map is centred so that the central line of north-south meridian at 0 degrees longitude goes through Greenwich, England. The ArcGIS also describes:
Mercator is a cylindrical projection. The meridians are vertical lines, parallel to each other, and equally spaced, and they extend to infinity when approaching the poles. The lines of (east-west) latitude are horizontal straight lines, perpendicular to the meridians and the same length as the equator, but they become farther apart toward the poles. The poles project to infinity and cannot be shown on the map.
World map in Mercator-style projection, by Miaow Miaow for Wikipedia (CC3.0). Note the exaggerated projection-sizes for Canada’s Ellesmere Island, Greenland, and the grand apparent whopper that is Antarctica. It’s also the “classic” problem of mapping a 3-dimensional sphere that is our world onto a 2-dimensional plane that is the common map.
Epitaph (grave plate) for Gerhard Mercator, inside Salvatorkirche. The German translation to the original Latin inscription can be found here.
Closeup view of Mercator’s epitaph.
Mercator memorial fountain, in front of Duisburg city hall.
Mercatorbrunnen (Mercator memorial fountain).
“Hommage à Mercator”, by Friedrich Werthmann, 1963. Across the street in the background is an archaeological site including the location of Mercator’s house.
Duisburg Rathaus & Salvatorkirche at left & right, respectively, as viewed from Alte Post. The Salvatorkirche is the city’s oldest building of worship with a temple first established at the site in the late 9th-century CE. The roots of the present-day church go back to the 14th-15th century CE.
The city’s central station is presently undergoing massive construction. The signage shown here used to hang above tracks 12 & 13.
Deutschland-Ticket for May 2025, purchased on the mobile iOS MVV-App the day before my scheduled flight to Europe. The purchase details ran almost identical to 2024.
Except the first Wiki image, I made all remaining images above with an iPhone15 on 13 May 2025. This post composed within Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com.
In 1933, the Nobel Prize Foundation awarded the physics prize jointly to Dr. Erwin Schrödinger and Dr. Paul Dirac for their development of techniques to solve problems in the burgeoning field of atomic physics. Schrödinger established the system of wave mechanics to study the motion within atoms and molecules. The mathematical forms for the wave properties of matter directly led to solutions as well as further insights in modern atomic physics.
The following images show some of the places where Schrödinger (1887–1961) spent time in his work- and home-life: traces he left behind in Vienna. He and his wife are buried in the Tirolean town of Alpbach.
University of Vienna (1.)
Next to the Ringstraße is the University of Vienna main building by Heinrich Ferstel and inaugurated in 1884.
Erwin’s youthful gaze is part of the university’s display of its Nobel Prize laureates.
Arkadenhof (arcade courtyard).
Memorial statue in Arkadenhof: Erwin Schrödinger’s equation in quantum mechanics is what Newton’s equation “F = ma” is to classical mechanics.
(2nd) Institute of Physics (9.)
Former location of the (second) Physics Institute, 1875 to 1913.
Memorial plaque on the exterior wall, in recognition of some of the scientists who once worked at the Physics Institute, including Stefan, Boltzmann, Meyer, Meitner, Hess, and Schrödinger.
Schrödinger Residence (9.)
Building address Pasteurgasse 4, where Schrödinger lived for a number of years, near the Strudlhofstiege staircase.
Memorial plaque at Pasteurgasse 4: “University of Vienna professor, physicist, and Nobel Prize laureate Erwin Schrödinger lived in this building from 1956 to 1961.”
I made all photos above with an iPhone15 on 6 Jul 2024. This post composed with Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-t9q.
The last time took place in La Serena, Chile at the end of 2011. Not only was it goodbye to Gemini South and Chile after 5 years, I said farewell to astronomy after almost 20 years.
But time is a tricky thing, and the moment had arrived: I had another promise to keep.
Fast forward to 2024, and I’m in the Bay Area. After reaching out a number of weeks ago, it’s wonderful to see them again after many years. They’ve kindly invited me to the SETI Institute where they work. I split from day-to-day science, but science never left, because I’m nerding out in a big way at the home of a big scientific effort: the Search for Extra-Terrestrial Intelligence.
Guest in Mountain View.
Cozy wide-open space, to house a number of multidisciplinary scientists to explore and study SETI themes.
Studio for SETI-hosted podcasts.
J&J, whom I met at Gemini, moved onto SOFIA: Stratospheric Observatory For Infrared Astronomy, fitted into a modified Boeing 747SP.
Dr. Jill Tarter: co-founder of SETI.
Dr. Frank Drake: 1st pres., SETI trustees board.
I’m nerding out in a big way: Leonhard Euler, and the famous Euler identity: e^(i•pi) = -1.
1593: Giordano Bruno suggests possibility of life on other planets; tried & executed for heresy. 1610: Galileo Galilei discovers 4 moons orbiting Jupiter, evidence against geocentric universe; convicted of heresy & sentenced to house arrest.
I have fond memories of seeing this on the big screen. 1997: the movie “Contact” is released with Jodie Foster in the lead role as Dr. Ellie Arroway, based loosely on SETI Institute co-founder Dr. Jill Tarter.
“To the SETI Institute gang, all my best! Jodie Foster.” (Arecibo)
“To the SETI Institute: live long and prosper! Leonard Nimoy.” (Celebrating 40 Years of the Drake Equation)
2020: COSMIC SETI installed at the VLA in New Mexico. 2022: 🇨🇦 CHIME in operation at SETI Institute’s HCRO in northern California.
Model of a segment for the 6.5-metre (21.3-foot) primary mirror of the JWST (James Webb Space Telescope).
Meeting room with SETI timeline on the wall.
Dr. Frank Drake and his equation to estimate the number of civilizations in our Galaxy.
Astronomers: 2 active, 1 lapsed.
I made all photos above with an iPhone15 on 8 Nov 2024 (travel day 11 in the Bay Area). This post composed with Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com.
In south-central Alberta, a leisurely 1.5 to 2 hour drive northeast from Calgary takes me past trucks, farm equipment, drilling rigs; through undulating hills and open fields of grain.
Population at a touch under 9-thousand, the city straddles the gentle flow of the Red Deer River. I’m led here by the notable attractions, and integrated over a couple of days here, they do not disappoint.
“Welcome to Drumheller”: sign and pullout next to highway AB-9, on approach into town from the south. Photo, 25 Sep 2024.
Fotoeins Fotografie 