One-third of the 2025 travel summer is complete; 30 days done in Europe’s Schengen Zone, 60 more to go.
What is now the U3 line through southwest Berlin began life as an “brand new extension of transport service” into a growing part of the capital city in the early 20th-century. These are 5 to highlight here.
Heidelberger Platz, 1883.
Podbielskiallee, 1913.
Dahlem-Dorf, 1913.
Freie Universität (Thielplatz), 1913.
Krumme Lanke, 1929.
I’m learning about Alfred Grenander’s architectural fingerprints in Berlin, particularly with the U-Bahn stations which remain today.
Track level, U3 station Heidelberger Platz.
Images of Heidelberg appear in alcoves throughout the station. The image at centre is…
…a well-known and well-photographed motif: “view of Heidelberg from Philosophers’ Path”. I have fond memories of living there from 2001 to 2003.
U3 station Podbielskiallee.
The top of the weather vane says “1913”, and inside the white-U are 3 fish. The name appears in the German Fraktur font.
U3 station Dahlem-Dorf with its famous thatched roof.
Interior, U3 station Dahlem-Dorf.
Interior from street-level down to track-level, U3 station Dahlem-Dorf.
U3 station Freie Universität, originally called Thielplatz: entrance building.
U3 terminus (for now) Krumme Lanke, track-level.
In front of Krumme Lanke station at street level is an open plaza named after Alfred Grenander, who designed in 1929 this very modern-looking entry building for the station.
“Alfred Grenander (1863-1931), Swedish architect who designed around 70 stations for the Berlin elevated and underground railway from 1902 to 1931, as well as the entrance building at Krumme Lanke station.” This sign appears just outside Krumme Lanke station and next to Fischerhüttenstrasse.
U3 line map, from Krumme Lanke station (via QR by BVG). Intersections with U-Bahn and S-Bahn are shown, as well as travel times to other stations on the U3 line. In full operation, a complete one-way trip to Warschauer Straße is 40 minutes.
Except for the very final image (Perlschnur), I made all other images above with an iPhone15 on 7 June 2025. This post composed within Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com.
It’s channel 1: the national broadcaster ARD (*), known informally by many as “Das Erste” or “The First”. Their studios look grand, modern, and imposing, and hide a grand piece of history in physics.
Like most places of higher learning, they start modestly, and in Berlin’s case, the late-19th and early 20th-century at the University of Berlin (now: Humboldt University) burst at the seams with ideas flowing in the natural sciences and social sciences, at a time when the city itself welcomed openness and creativity.
Berlin is best known for its history, decades of extended trauma, its architecture, and a cultural centre with contemporary art and electronic music. I know Berlin as a place of world-changing science with renowned scientists, whose names massively stamped the last half of my undergraduate years.
(*) ARD: Arbeitsgemeinschaft der öffentlich-rechtlichen Rundfunkanstalten der Bundesrepublik Deutschland; translated as “Association of Public Broadcasting Corporations of the Federal Republic of Germany”. It’s something like Canada’s CBC, Australia’s ABC, or Great Britain’s BBC.
ARD Hauptstadtstudio
ARD (national channel no.1) radio- & tv-studios at Wilhelmstrasse next to Marshallbrücke. On the right side (west-facing wall) is a memorial plaque near the back corner, hidden behind the tree.
Left panel: From 1996 to 1998, the building owner association SFB & WDR led construction of the Berlin radio- & television-studios for the broadcaster ARD.
Right panel: Built for Hermann Helmholtz, the Physics Institute of the University of Berlin once stood at this spot from 1878 to 1945. Key physicists worked here, including James Franck, Gustav Hertz, Walther Nernst, Wilhelm Wien, Max Planck. In his institute lecture on 14 December 1900, Planck described the early principles of quantum theory.
Staatsbibliothek zu Berlin
“From 1914 to 1932, Albert Einstein worked here as a member of the Prussian Academy of Sciences.” State Library of Berlin is located at Unter den Linden 8.
The Einstein plaque appears at left in this image, next to the doors of the former Prussian Academy of Sciences. On 4 November 1915, Einstein presents his “field equations” for general relativity in a lecture to the Academy.
Humboldt University
Formerly the University of Berlin, today’s Humboldt University main building (next door to the State Library) greets visitors with a statue of physicist Hermann Helmholtz. Einstein also presented lectures about his developments in general relativity to the university’s physics institute.
Max Planck, who discovered ‘h’ the elementary quantum of action, taught in this building from 1889 to 1928. This memorial plaque is on the outer wall of the main building’s west wing. Planck is also honoured with a memorial statue in the main building’s front courtyard. Today, a massive German network of research institutes is named in his honour as the Max Planck Gesellschaft; I had the great privilege of spending 2 years at the Max Planck Institute for Astronomy in Heidelberg.
In 1931, American physicist Millikan was invited to Berlin. In this incredible image of a dinner-gathering in Berlin on 12 November 1931, seated from left to right, respectively, are: Walther Ernst, 1920 Nobel Prize in Chemistry; Albert Einstein, 1921 Nobel Prize in Physics; Max Planck, 1918 Nobel Prize in Physics; Robert Millikan, 1923 Nobel Prize in Physics; and Max von Laue, 1914 Nobel Prize in Physics.
I made all images above with an iPhone15 on 27 May 2025. This post composed within Jetpack for iOS appears on Fotoeins Fotografie at fotoeins DOT com.
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.
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