Fotoeins Fotografie

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Posts from the ‘Science’ category

Danube, Donau, Christian Stemper, Wien Tourismus

My Vienna: 30 days of spring from the 6

Danube morning: photo by Christian Stemper, courtesy of Wien Tourismus (no.50401).

With this entry’s appearance, I’m on the other side of the world, 8500 kilometres away.

I dashed in and out of Vienna a handful of times between 2001 and 2003 when I lived in Heidelberg; but I have no visual records of that period in time. I’ve returned to Austria’s capital city for the first time since 2018. I wondered then how a stay in the Mariahilf, the city’s 6th district, would go.

That time is now, because I’m spending a month in the 6.

To minimize weight, I’m experimenting:
•   32-L backpack as the 1 and only piece of (carry-on) luggage, and
•   “no bricks no heavy glass”, but a compact mirrorless Fuji X70 camera.

The apartment location and neighbourhood are ideal. I’m within easy reach of the city’s U-Bahn, surrounded by the U3, U4, and U6 metro lines. I’ve already located a drugstore and several grocery stores, all inside a trivial 0.5 km (0.3 mi) walk. I’ve also been told I’ll have many Viennese coffees and several meals in the area.

There’s a lot to pursue, see, and do; and there’s no time to waste.

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My Berlin: Humboldt University’s court of honour

Above/featured: Illuminated by autumn morning light, Helmholtz stands proud in the Humboldt University’s “Ehrenhof”.

If you’re in Berlin for the first time, you’ll likely make your way to the city centre and the classic tree-lined avenue Unter den Linden. When you’re not people-watching, you’ll likely admire the architecture along the way. Across the street from Bebelplatz plaza is the main building of the Humboldt University (HU). In its front court or “court of honour” are several memorial statues dedicated to some key figures in the history of arts, sciences, and the university: Hermann Helmholtz, Lise Meitner, Max Planck, and Theodor Mommsen.

The Humboldt University was one of many stops in Berlin during my visit in November 2021.

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Friedhof Wannsee Lindenstrasse, Neuer Friedhof Wannsee, Friedhof Wannsee II, Berlin, Germany, Deutschland, fotoeins.com

My Berlin: Wannsee cemetery with Helmholtz, Fischer, Conrad

Above/featured: Friedhof Wannsee Lindenstrasse with Andreaskirche in the background.

I came here looking for a physicist, but I also found a Nobel-Prize winning chemist and a successful banker.

In the southwest corner of metropolitan Berlin tucked away under rows of leafy trees in a quiet residential neighbourhood in Wannsee is a small cemetery, next to a tall red brick church Andreaskirche. With the main (east) entrance off Lindenstrasse, the cemetery is called Friedhof Wannsee Lindenstrasse; alternate names include “Neuer Friedhof Wannsee” and “Friedhof Wannsee II.” Opened in 1887, the cemetery is one of the smallest in the city with an area about 1.9 hectares (19-thousand square metres) or a shade under 5 acres.

(My day trip to Wannsee was only one element of my “quick” 11-day hop to Berlin in autumn 2021.)

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My Berlin: Alicja Kwade, bridging art and science

Above/featured: Alicja Kwade exhibition, at the Berlinische Galerie. HL:X70.

In October 2021, I watched DW Culture’s Arts.21 feature on Polish-German artist Alicja Kwade. I knew I had to see her work and exhibition in person, but would it be even possible? My answer arrived six weeks later with a quick jump home to Berlin.

All of Kwade’s sculptural pieces in her exhibition, “In Abwesenheit” (In Absence)”, are “self-portraits.” But none of them show her face; the pieces aren’t necessarily simple, nor are they “selfies” characterized by the present vernacular. She is not physically present, and yet, every piece provides the visitor a glimpse into her mindset including questions she raises about the volatility of the human condition and about where we fit within a very large universe.

As former research scientist, I’m recognizing and I’m loving the influences on her art. She is clearly very interested in mathematics, physics, astrophysics, biology, genetics; but she’d be the first to admit she’d need multiple lives to completely fulfill all of her interests. The deconstruction of “self” into precise scientific elements is another way of expressing those (dreaded) “selfies” or self-portraits. I admire the clever play: it’s the breakdown into those elements that tell us what she is, and it’s the measured synthesis of those elements into the broad strokes of her sculptures that tell us who she is.

We’re all playing this game. Everyday things seem so important. But then you zoom out and realize that you’re standing with another billion [people] on a spinning sphere. With that perspective, you’re reminded to just be glad you’re here at all.

– 16 April 2019, Artnet News about her rooftop commission at New York City’s Metropolitan Museum of Art.


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Deutsches Museum, Muenchen, Munich, Bayern, Bavaria, Oberbayern, Upper Bavaria, Deutschland, Germany, fotoeins.com

Fotoeins Friday around Munich: Deutsches Museum

You cannot possibly take in every exhibit inside the massive Deutsches Museum (German Museum) in a single afternoon or even an entire day. At some point, the mind short circuits, feet will ache, and the stomach sends urgent “I am hungy” messages to the brain. But for a physicist and scientist by training, this museum is a real joy.

With the temporary exhibition “Auf zu neuen Energien” (Onto new forms of energy), I learn about “green power” in Germany, about where in the country solar and wind power is best “collected” or generated. Figuring that out depends on lots of specific meteorological data. The two figures/plots show average annual solar incident radiation at the surface and average annual wind speed at an elevation of 80 metres (typical height of a wind turbine). The sunniest areas indicated with red above are in the southern quarter of the country, and the windiest regions indicated with red below are by the open seas in the north and up in highlands and mountains.

Deutsches Museum, Deutscher Wetterdienst, DWD, annual solar incidence, Muenchen, Munich, Bayern, Bavaria, Oberbayern, Upper Bavaria, Deutschland, Germany, fotoeins.com

Average annual solar incidence, in kilowatt-hours per square metre (1 kWh/m^2 = 3600 kJ/m^2). Courtesy of the Deutscher Wetterdienst (German Meteorological Service), this plot shows how the country’s southern quarter receives the most sun.

Deutsches Museum, Deutscher Wetterdienst, DWD, annual average wind speed, Muenchen, Munich, Bayern, Bavaria, Oberbayern, Upper Bavaria, Deutschland, Germany, fotoeins.com

Average annual wind speed at an elevation of 80 metres, the typical height of a wind turbine. Wind speeds are shown between 3 to 10 metres per second (11 to 36 kilometres per hour). The reddest areas in the northern lowlands by the sea and in highlands and mountains have highest average wind speeds above 7 m/s (25 km/h). Image/plot from Deutscher Wetterdienst (German Meteorological Service).

I made all three photos above on 23 Feb 2017. This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-kpM.

Ludwig Boltzmann, Arkadenhof, Universitaet Wien, University of Vienna, physicist, physics, Vienna, Wien, Oesterreich, Austria, fotoeins.com

Fotoeins Friday at Uni Vienna: Ludwig Boltzmann

I’ve highlighted notable physicists who’ve been memorialized within the Arcade Courtyard in the main building of the University of Vienna:

2 Apr: Lise Meitner;
9 Apr: Christian Doppler, Erwin Schrödinger;
16 Apr: Joseph Littrow, Karl Littrow;
23 Apr: Josef Stefan;
30 Apr: Ludwig Boltzmann.

These are all names whose work and discovery form the historical and scientific basis of my university education in the field of physics.


The inscription for physicist and university professor Ludwig Boltzmann reads:

Ludwig Boltzmann, 1844-1906:
Professor of mathematics, 1873-1876;
Professor of theoretical physics, 1894-1900 and 1902-1906.

Buried in Vienna’s Central Cemetery, Boltzmannn’s gravestone includes the equation for entropy in statistical mechanics and thermodynamics.

S \,=\, k \log W

In collaboration with Josef Stefan, the Stefan-Boltzmann Law describes how an object that absorbs all radiation falling on its surface emits radiative intensity (I, radiation energy per unit time per unit area) that’s proportional to the fourth power in temperature T with constant emissivity ε (between 0 and 1) and Stefan-Boltzmann constant σ.

I \,=\, \epsilon \sigma T^4

Ludwig Boltzmann was also one of Lise Meitner’s professors and advisors at the university. Meitner would become the 3rd woman to receive a doctorate in physics from the University of Vienna, and would go on to describe the process of nuclear fission.

The university’s historical main building is inside the city’s Old Town which has been inscribed as UNESCO World Heritage Site since 2001. I made the photo above on 16 May 2018 with a Fujifilm X70 fixed-lens prime and the following settings: 1/30-sec, f/5.6, ISO1000, and 18.5mm focal length (28mm full-frame equivalent). This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-iGz.

Josef Stefan, Arkadenhof, Universitaet Wien, University of Vienna, physicist, physics, Vienna, Wien, Oesterreich, Austria, fotoeins.com

Fotoeins Friday at Uni Vienna: Josef Stefan

Throughout the month, I’m highlighting notable physicists who’ve been memorialized within the Arcade Courtyard in the main building of the University of Vienna:

2 Apr: Lise Meitner;
9 Apr: Christian Doppler, Erwin Schrödinger;
16 Apr: Joseph Littrow, Karl Littrow;
23 Apr: Josef Stefan;
30 Apr: Ludwig Boltzmann.

These are all names whose work and discovery form the historical and scientific basis of my university education in the field of physics.


The memorial to Josef Stefan (Jožef Štefan) includes a small inscription:

Josef Stefan
Professor of physics, 1863-1893
Born 1835, died 1893

An important physics equation is the Stefan-Boltzmann Law, which describes how an object that absorbs all radiation falling on its surface emits radiative intensity I (radiation energy per unit time per unit area) that is proportional to the fourth power in temperature T; the other two quantities are constants: emissivity ε between 0 and 1, and the Stefan-Boltzmann constant σ:

I \,=\, \epsilon \sigma T^4

Both Stefan and Boltzmann are buried in Vienna’s Central Cemetery. Boltzmann’s gravestone includes his entropy equation. Stefan does not have his own grave; instead, his descendants in the Munk family have a gravestone.

The university’s historical main building is inside the city’s Old Town which has been inscribed as UNESCO World Heritage Site since 2001. I made the photo above on 16 May 2018 with a Fujifilm X70 fixed-lens prime and the following settings: 1/60-sec, f/3.2, ISO1000, and 18.5mm focal length (28mm full-frame equivalent). This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-iGt.

Josef Johann von Littrow, Karl von Littrow, Universitaet Wien, University of Vienna, physicist, physics, Arkadenhof, Vienna, Wien, Austria, Oesterreich, fotoeins.com

Fotoeins Friday at Uni Vienna: Joseph & Karl Littrow

Throughout the month, I’m highlighting notable physicists who’ve been memorialized within the Arcade Courtyard in the main building of the University of Vienna:

2 Apr: Lise Meitner;
9 Apr: Christian Doppler, Erwin Schrödinger;
16 Apr: Joseph Littrow, Karl Littrow;
23 Apr: Josef Stefan;
30 Apr: Ludwig Boltzmann.

These are all names whose work and discovery form the historical and scientific basis of my university education in the field of physics.


A wall plaque memorializes astronomers Joseph Littrow and (his son) Karl Littrow at left and right, respectively. Joseph was director of the Vienna Observatory from 1819 to 1842; Karl succeeded his father as director from 1842 to 1877.

The Littrow crater on the Moon is named after Joseph, but he’s also best known in physics for his optics inventions: the Littrow prism and the Littrow configuration optimizing the performance of a spectrograph with a specially designed diffraction grating.

The university’s historical main building is inside the city’s Old Town which has been inscribed as UNESCO World Heritage Site since 2001. I made the photo above on 16 May 2018 with a Fujifilm X70 fixed-lens prime and the following settings: 1/30-sec, f/2.8, ISO1000, and 18.5mm focal length (28mm full-frame equivalent). This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-iGr.

Christian Doppler, Erwin Schroedinger, Arkadenhof, Universitaet Wien, University of Vienna, physicist, physics, Vienna, Wien, Oesterreich, Austria, fotoeins.com

Fotoeins Friday at Uni Vienna: Doppler & Schrödinger

This month I’m highlighting notable physicists who’ve been memorialized within the Arcade Courtyard in the main building of the University of Vienna:

2 Apr: Lise Meitner;
9 Apr: Christian Doppler, Erwin Schrödinger;
16 Apr: Joseph Littrow, Karl Littrow;
23 Apr: Josef Stefan;
30 Apr: Ludwig Boltzmann.

These are names whose work and discovery form part of the historical and scientific basis of my university education in the field of physics.


Shown in the image are memorials to Christian Doppler and Erwin Schrödinger at left and right, respectively. My translation to the inscription on the Doppler memorial inscription reads:

Christian Doppler, 1803-1853:
Professor of physics at Vienna University, 1850-1853.
The Doppler principle has ensured the Doppler name for all time.

With his birth house in Salzburg as backdrop, I briefly describe the physics of the Doppler effect.

The Schrödinger memorial highlights an early 20th-century revolution in science in the form of quantum mechanics: the physics of the atom and its constituents. The well-known equation representing Newton’s 2nd Law, “F = ma”, is to classical mechanics, as the following equation is to quantum mechanics.

i \hbar \dot{\psi} \,=\, H \psi

I was able to “localize” the final resting place for Schrödinger and his wife in the Austrian alpine town of Alpbach. The above equation appears on the their grave in Alpbach and on the memorial at the University of Vienna. The equation is a generalized form of the time-dependent Schrödinger equation describing a physical system, represented by ψ, which changes with time.

The university’s historical main building is inside the city’s Old Town which has been inscribed as UNESCO World Heritage Site since 2001. I made the photo above on 16 May 2018 with a Fujifilm X70 fixed-lens prime and the following settings: 1/60-sec, f/6.4, ISO1000, and 18.5mm focal length (28mm full-frame equivalent). This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-iGo.

Lise Meitner, Arkadenhof, Universitaet Wien, University of Vienna, physicist, physics, Vienna, Wien, Oesterreich, Austria, fotoeins.com

Fotoeins Friday at Uni Vienna: Lise Meitner

Throughout the month, I’m highlighting notable physicists who’ve been memorialized within the Arcade Courtyard in the main building of the University of Vienna:

2 Apr: Lise Meitner;
9 Apr: Christian Doppler, Erwin Schrödinger;
16 Apr: Joseph Littrow, Karl Littrow;
23 Apr: Josef Stefan;
30 Apr: Ludwig Boltzmann.

These are all names whose work and discovery form the historical and scientific basis of my university education in the field of physics.


Lise Meitner (1878-1968) was an Austrian physicist whose work with chemist Otto Hahn produced breakthroughs in our understanding of atomic and nuclear physics. Meitner overcame obstacles blocking women from studying and working at universities in the early 20th-century. She wanted to study at the University of Vienna, and thanks to her parents’ support, she studied on her own and successfully passed the university’s entrance examination in 1901. She studied physics over the next five years; physicist Ludwig Boltzmann was one of her instructors and advisors. In 1906, Meitner became the 3rd woman at the university to receive a doctorate in physics (after Olga Ehrenhaft-Steindler and Selma Freund). In 1907, she moved to Berlin where she would stay for over 30 years. In 1926, she became one of the first women appointed to associate professor at Berlin University and the first woman as professor of physics in Germany. Her Jewish lineage meant loss of title and employment, and in mid-1938, a hasty departure from Germany and exile to Sweden. In 1939, she and her nephew physicist Otto Frisch published a short breakthrough paper with their theoretical analysis of the newly discovered process of “nuclear fission” in experiments with uranium and thorium by Otto Hahn and Fritz Strassmann. Later, she refused to help with the construction of an atomic bomb and objected to the use of nuclear weapons for the rest of her life.

Like many, I believe Lise Meitner should have been honoured as co-Laureate for the 1944 Nobel Prize in Chemistry awarded solely to Otto Hahn. In mid-2016, the University of Vienna unveiled a monument in her honour.

The university’s historical main building is inside the city’s Old Town which has been inscribed as UNESCO World Heritage Site since 2001. I made the photo above on 16 May 2018 with a Fujifilm X70 fixed-lens prime and the following settings: 1/60-sec, f/9, ISO1000, and 18.5mm focal length (28mm full-frame equivalent). This post appears on Fotoeins Fotografie at fotoeins DOT com as https://wp.me/p1BIdT-iFJ.

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