Over the 20th century technology has pushed forward in many fields. As there were huge investments needed the public campaigns to support new technology without much further reflection of potential consequences have pulled many western societies into risky technologies. Except the Club of Rome there were very few to question the naïve beliefs that technological change will make societies rich and potentially even more equal. The recent report “Climate Inequality Report 2023: Unequal Contributions to Climate Change” has debunked both of these claims. More flying across the planet, particularly short city hopping, has allowed few persons to reap the benefits of the jet-set world, but contributed to climate change in excessive quantities. This is a fact when we compare major world regions among each other as well as within each country. It has to be the wealthy countries that have to shoulder the biggest share of the costs. It has to be the wealthy that pay higher contributions for their pollution. Society has to reign in technology more than ever before. Moreover, we still have to get the income and pollution distribution organised in a better way. It is not only an implementation challenge, but the major question of the 21st century to repair the damage largely caused throughout the 20th century. 
20th Century
The 20th century has told us many lessons. History does not repeat itself, but it appears that new variants of old themes keep coming back. Slowly passing the century like a movie in decades instead of episodes, we witness socio-emotional tides. The first decade, the 00s intensify the beginning of urban planning and social revolutions. The 10s show the arousal and subsequent extinction of masses of people in trenches. The 20s were described as the Carefree Twenties. In the 30s we observed the rising tides of fascist organisations followed shortly afterwards by the disastrous 40s. After the Shoah and the World War the 50s were fabulous viewed from the U.S. and Western Europe. The 60s propagated sex, drugs and rock n’ roll spreading across continents. The wild 70s became almost inescapable through the continued rise of mass media. The 80s were depicted as the colourful 80s as the 2 previous decades had set the scene for psychedelic colours. The 1990s have been coined as the gay 90s by some. Coming out as a gay person became easier and Western societies more sensitive and open to diversity. The back cover of the recent publication by Aurélien Bellanger “Le vingtième siècle” (The 20th century) speaks of the book as “roman polyphonique virtuose”. I look back on the 20th century as “polyphone” in many respects. It would be an illusion to believe we can only keep the nice sounding harmonies without the tensions or dissonances. 
1900s
1900 marks the year of the 5th world exhibition in Paris. The Eiffel tower, built for the 4th exhibition in Paris remains the iconic attraction despite the new architecture that is added to Paris as the Petit and Grand Palais as well as the 1st Metro line. Art Nouveau style adds to already impressive architecture in and around Paris. With the planning horizons of several years in advance of events, urban planning with all its facets of urban infrastructure and architecture becomes much of a defining scientific discipline for decades and for most of the time of the century. Grand urban architecture and design constitute just another form of competition between nation states. Most of them want to show off their imperialist acquisitions and, what they define as “curiosities” at the time.
Habib (2005, pp.502) singles out Arthur Schopenhauer and Friedrich Nietzsche as “heterological thinkers” who coin major thoughts in the late 19th century that shall influence the beginning of the 20th century right from the year 1900 onwards. “The world should be formed in your image by your reason, your will, and your love! And truly, it will be to your happiness you enlightened men!” (Nietzsche. Thus spoke Zarathustra 1978, p.110). In retrospect from the 21st century we shall doubt this overly positive approach to human intentions and their will to form the world according to their abstracting ideas only. Tensions between technology and society became visible and it took many decades before society became conscious that it is up to society to choose technologies they preferred.
The planning for the Brussel Expo 1910 started right after the previous Expo 1905 in Liège. Protests in Brussels accompanied already the choice of terrain for the Expo, but the governors and shareholders of the enterprise decided 1906 for a site near the “forêt de Soignes”, where trees had to be cut for access to the construction site and for future visitors under local protest. Women workers were present to exhibit the low pay of women in industries. Child labour was documented with shocking images. Around the globe labour movements started to raise attention. In the U.S. the National Women’s Trade Union League (1903) was founded as well as the National Child Labor Committee (1904). “Bloody Sunday” in St. Petersburg (1905) saw the killing of peaceful protestors in front of the Zsar’s palace, which ignited the Russian Revolution of 1905 and the creation of the Russian Parliament. Some of these issues (child labor) keep returning to our social agenda well into the 21st century.
Einstein’s publication of the theory of special relativity (1905) as well as challenges from social philosophy reflects the huge discrepancy between advancement of the sciences and the living conditions of the masses. Social theories and science advances foreshadow the violent turbulence throughout the 20th century.
(Sources: (1) Max Welch Guerra et al. (2023). European Planning History in the 20th Century: A Continent of Urban Planning. Routledge. (2) St. James Encyclopedia of Labor History Worldwide: Major Events in Labor History and Their Impact, Neil Schlager (2004). (3) Images from I. Van Hasselt(1980) Bruxelles Expo 1910: l’incendie / de brand. J Stevens. 
10s
The 1910s have been eclipsed completely by “the Great War” between 1914 to 1918. The 1st world war certainly was the most horrific period of the decade of revolutions and mass arousal. From a global history perspective the years preceding and shortly after the humanitarian disasters deserve more attention, if we were to derive lessons for prevention of other world encompassing wars of imperialist states. The numbers 1st, 2nd, … 3rd (?) world war suggest an unescapable numbering of events. We no longer can think in this trivialising logic of war or historical determinism. Empires go to war more easily than democracies. This was the social scientists’ consensus after the Great War. It took several years for many European states to turn more democratic, allowing women to vote, or introduce more robust health and social security systems. Powerful aristocracies would not cede power easily, only the widespread poverty after the Great War and the human losses discredited many aristocratic regimes throughout Europe. The imperialist dominance of the beginning of the 1910s produced a spirit of ruthless conquest and exploitation of colonies around the world. It took another global war and almost half a century to dismantle these regimes. To understand global alliances and impediments of wars in the 21st century, the early 1910s are instructive as they inform the restitution of artefacts debate in the 2020s. In the history of ideas, the 1910s are probably best characterised as the period of attempting to turn “grand ideas” into political facts on the globe. The rise of Marxist ideology, liberal and fascist counter movements started to take powerful roots at the end of the 1910s. All these ideas and factual changes of the maps of power still seem to govern a lot of international politics even today. 
Construction
Construction as an industrial sector was growing strongly in the last decade. Corona crises, supply chain disruptions have slowed growth in the last two years, but the sector was still growing in terms of employment. The topic of skill and employee shortages hardened from year to year. In March 2023 the sector has more time to reflect on the somehow rapid, if not sometimes chaotic growth of the previous decade. The macro-economic scenario has changed now. Following on supply chain disruptions, we saw the high inflation rates of raw materials. The war of Russia against Ukraine caused energy prices to soar and eventually come down again. Latest worry is the increase in interest rates to finance construction projects of public, private and the business sector.
The whole sector is known for its economic role of forerunner of economic cycles, up or down. So, what are the prospects? Not so rosy, as the experts explain for example on the expert forum of the Belgian construction forum. The official from the Belgian National Bank announced a rather bleak outlook for the sector. New construction is stalling, but the renovation of buildings, especially for the purpose of reducing energy consumption is still strong and growing. Long-term reduction of emissions keeps the sector busy, thanks to the EU green deal in my opinion. The public, private and business investments in buildings all keep growth from turning negative. 2 big worries remain: (1) skill shortages and the lack of employees signalled in job openings in the sector is high and still rising; (2) the scarcity of women employed in the sector is still trailing most other sectors. Most companies have seen earnings grow over the last decade, sufficient time to build up reserves for the tougher quarters to come. Skill shortages and gender biases are harder to overcome. The Construction Forum in Brussels addressed both topics and tries to convince employers and the younger generation. Construction companies have to work on their male-dominated image was one of the take home messages Hélène de Troostemberg, the Director of Build Up pronounced.
It is not certainly not enough to have a woman as moderator of a panel and an all-female singers group accompanying the presentations. Women as architects, technicians and builders will make the sector even more attractive for the next generation of men as well. Aging of employees in the sector is another tough issue waiting for innovative solutions. Digitalisation of every step in the value chain is an additional necessary step. The leadership and trade unions in the sector are well aware of these facts. Maybe next year women engineers will pilot the robotics demonstration rather than being in charge of building a nice atmosphere with their songs. I must admit I liked the intro song to the Forum: “We build this city on rock ‘n role”, but I am less sure whether rock ‘n role will solve the gender and recruiting issue of the sector. However, naming and framing the problem(s) is already part of the solution.
Spring2023
Spring has sprung, a little bit early in 2023. On the 16th of March in the vicinity of Paris, where Caillebotte designed his impressionist garden. It is still 4 weeks until Easter. The spring flowers will hardly survive until then. Hence, we prepare for an early summer, nice because of less heating, but the vegetation is suffering in the region due to the lack of rain. Hay fever for millions of persons will start early this year as well. The damages from a fire in the nearby forest “Sénart” from 2018 have still not really disappeared. It is expensive and needs a lot of workers, equipment and knowhow to avoid the same old mistakes of planting mono-cultures of trees again. When will they ever learn, when will they ever learn.
Caillebotte
Gustave Caillebotte has done it again. Son of a great beneficiary of war efforts himself. He started with support from his father’s fortune on a painting career. Soon after his father’s death, he joined the group of “alternative artists”, later called the impressionists in France. On the 1.2.2023 the Musée d’Orsay acquired a key painting of Caillebotte for 43 Million € with the help of a donation by LVMH. Where does the hype come from? A catalogue of the exhibition of the painter “Gustave Caillebotte, The painter’s eye” from the National Gallery of Art in Washington from 2015 established Caillebotte again as a key person of the impressionist movement. Rich in diversity of motifs, the painter and supporter of the impressionists (Philantropist) has foreseen the challenge photography could bring to painting. The painter’s eye is well explained by Michael Marrinan (pp.22) in the catalogue. In fact, the spatial depth of the views of the streets of Paris is a precursor to many photographers and movies of several decades later. Caillebotte’s images of Paris depict well the mixed feelings about a daunting city size and the isolation of people captured in their own little inner circles with little communication despite or because of the noisy surroundings. Misty atmospheres allow to focus on impressions. Almost meditative walking in the city is his modern topic. Reflecting on painting as profession versus painting as artist is somehow an impressionist’s sociology of professions. Gustave Caillebotte did not have to paint for money and he was aware of social class differences as son of a factory owner. It did not spoil his artistic view with social facts, but rather tried to reveal the intrinsic beauty not only of landscapes, but ordinary working people. Other impressionists painted beautiful ballerinas, Caillebotte painted workers and sometimes more challenging parts of Paris in his early years. With climate change near Caillebotte’s home in full swing, we shall “adore” the rainy days in Paris even more. And in the countryside, too. The painter’s eye reveals a visionary view of the modern and post-modern world. 
Flotow Stradella
Die Oper Stradella von Flotow wurde in 2006 eingehend besprochen. Sarah Hibbert hat ein immer wieder aktuelles Thema: Wie sollten vorherige Stilepochen in der Aufführungspraxis und der Komposition behandelt werden? Die Legende über den Sänger Stradella, der einem Fürsten die Braut ausgespannt hat und deswegen ermordet werden sollte, bietet einen interessanten (sex and crime) Plot. Wegen der Gesangskunst des Verführers, wollten die bestellten .Auftragsmörder den bezaubernden Sänger nicht töten. Tatort ist der Auftritt der Sängers in einer Kathedrale. Fritz von Flotow und Louis Niedermeyer haben beide fast zeitgleich eine Version des Librettos vertont. Es stellt sich nun die Frage, wie denn am besten der historische Stoff aus dem 17-ten Jahrhundert darzubieten ist. Beide Komponisten komponierten im Stil der romantischen Oper des 19-ten Jahrhunderts. Flotow wählt eine stärker historisierende Variante der mittelalterlichen Musik der Stradella-themen in seiner Oper. Die Klangfarben der mittelalterlichen Kirchenmusik passen aber nur schwerlich zu den Erwartungen des zeitgenössischen (1830er) Opernpublikums. Daraus resultiert,en eine spannende kompositorische Aufgabe und entsprechende Herausforderung für die Aufführung des Werks. Darüber hinaus müssen noch Unterschiede zwischen der ersten mehr populären Form der Oper für Paris (Vaudeville) und der später in Hamburg uraufgeführten Version der Flotowschen Stradella Fassung beachtet werden. Historisierung mit Anlehnungen an Gesänge von Palestrina sind nicht der Geschmack eines jeden im Publikum und der Kritiker. Grund genug, in die Opern mal wieder reinzuhören. Den Tenor, die Arie “Jungfrau Maria” singend, hätte ich wahrscheinlich auch nicht als Auftragsmörder töten können. Rolando Villazón ist darin recht überzeugend.
Quelle: Hibbert, S. 2006. Murder in the Cathedral. Stradella, Musical Power and Performing the Past in 1830s Paris. Music & Letters Vol 87 Nr. 4. doi:10.1093/ml/gcl081 (Photos, KS Kathedrale in Meaux, F).
20s
In retrospect from the 1930s and in prospect from the 1910s, the 1920s may well be described as “The tumultuous Twenties”. Several other summary notions are attributed to the 1920s. “Les années folles” in the French speaking world, “The Jazz years” within the U.S. or the “Wild 20s” in Germany coined the decade after the disillusion of the 1st world war. The economic and cultural revival after the period of atrocities has seen thriving city centres and comparatively little economic hardship until the Wall Street crashed on October 24th in 1929 the so-called “Black Thursday”. The party was suddenly over and a lengthy economic crisis spread globally. It was within this free spirit of the 1920s that the Fascist counter movements of the 30s started to take roots.
The 20s saw the skyscrapers soar and the credit-financed speculation was at its highest. Pierre Boudon (1991, pp. 137) characterises the architecture of the 1930s as “l’inversion des signes”. The Bauhaus of the 1920s was later forced into emigration. The film of F. Lang “Metropolis” (1927) prolonged the constructivist lines of the 1920s to a haunting vision of big cities with its daunting acceleration of economic and cultural experiences.
Walter Benjamin later referred to the method of technical reproduction as one of the major foundations for the mass movements and mass culture, which turned the relatively prosperous early and mid 20s into the disastrous 30s. Indeed, many scholars combine the 20s and 30s into one historical period as the rise and decline between the 2 world wars of the 20th century.
Certainly in terms of economic development many countries witnessed a steep rise in prosperity in the 20s followed by deep recession in the 30s. What went up in spectacular terms in the 20s, economic development, democratic participation, came down in the next decade due the rise of Fascist movements.
100 years later in the 2020s we still struggle with many of the same issues. Poverty and “Existenzminimum” were topics of the 2nd International congress of modern architecture in 1929 in Frankfurt. This reflects the lasting need to address “social issues” throughout decades, if not whole centuries of mankind. 
History
Approaching history with a personal touch is a powerful way of attracting persons into learning about others and themselves. The use of some personal belongings as part of a “history box” can be the beginning of an historical journey into the 30s, 40s, 50s or any other decade. It is an empowering tool for learners of all ages. Digging deeper into personal histories, societal constellations and societal change becomes alive through tiny little things. Communicating about these artefacts blends old and new narratives, just as much as the life courses of the “common woman or man” with the celebrities of the time. “Getting personal” is the hype in the time when social media want to define our life though endless nudging. Reflecting on origins is not what we tend to do, PhotoAPPs create retrospects for us, take it, or leave it. History is catching up on us. The fashion world reinvents history on a seasonal basis. After all, a bag is a bag is a bag. Or is it different from the one a person took to Auschwitz.
