March 20th in stamps Bismarck dismissed by Wilhelm II, Einstein publishes his general theory of relativity, Ferdinand Foch, Juliana

Here are some events that happened on March 20th. It could be an event or a person that died or was born on that day

1890 – Prime Minister of the German Empire Otto von Bismarck is dismissed by Emperor Wilhelm II.

Otto Eduard Leopold, Prince of Bismarck, Duke of Lauenburg (Born von Bismarck-Schönhausen; German: Otto Eduard Leopold Fürst von Bismarck, Herzog zu Lauenburg; 1 April 1815 – 30 July 1898), known as Otto von Bismarck, was a conservative Prussian statesman who dominated German and European affairs from the 1860s until 1890 and was the first Chancellor of the German Empire between 1871 and 1890. In 1862, King Wilhelm I appointed him as Minister President of Prussia, a position he would hold until 1890, with the exception of a short break in 1873.

He provoked three short, decisive wars against Denmark, Austria, and France. Following the victory against Austria, he abolished the supranational German Confederation and instead formed the North German Confederation as the first German national state in 1867, leading it as Federal Chancellor. This aligned the smaller North German states behind Prussia. Later receiving the support of the independent South German states in the Confederation's defeat of France, he formed the German Empire in 1871, unifying Germany with himself as Imperial Chancellor, while retaining control of Prussia at the same time. The new German nation excluded Austria, which had been Prussia's main opponent for predominance among the German states.


German First Day Cover issued for the 150 birthday anniversary of Otto von Bismarck

1915 – Albert Einstein publishes his general theory of relativity.

Albert Einstein (14 March 1879 – 18 April 1955) was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics (alongside quantum mechanics). His work is also known for its influence on the philosophy of science. He is best known to the general public for his mass–energy equivalence formula E = mc2, which has been dubbed "the world's most famous equation". He received the 1921 Nobel Prize in Physics "for his services to theoretical physics, and especially for his discovery of the law of the photoelectric effect", a pivotal step in the development of quantum theory.

The son of a salesman who later operated an electrochemical factory, Einstein was born in the German Empire but moved to Switzerland in 1895 and renounced his German citizenship in 1896. Specializing in physics and mathematics, he received his academic teaching diploma from the Swiss Federal Polytechnic School (German: eidgenössische polytechnische Schule) in Zürich in 1900. The following year, he acquired Swiss citizenship, which he kept for his entire life. After initially struggling to find work, from 1902 to 1909 he was employed as a patent examiner at the Swiss Patent Office in Bern.

Near the beginning of his career, Einstein thought that Newtonian mechanics was no longer enough to reconcile the laws of classical mechanics with the laws of the electromagnetic field. This led him to develop his special theory of relativity during his time at the Swiss Patent Office. In 1905, called his annus mirabilis (miracle year), he published four groundbreaking papers, which attracted the attention of the academic world; the first outlined the theory of the photoelectric effect, the second paper explained Brownian motion, the third paper introduced special relativity, and the fourth mass-energy equivalence. That year, at the age of 26, he was awarded a PhD by the University of Zurich.

Although initially treated with skepticism from many in the scientific community, Einstein's works gradually came to be recognised as significant advancements. He was invited to teach theoretical physics at the University of Bern in 1908 and the following year moved to the University of Zurich, then in 1911 to Charles University in Prague before returning to ETH (the newly renamed Federal Polytechnic School) in Zürich in 1912. In 1914, he was elected to the Prussian Academy of Sciences in Berlin, where he remained for 19 years. Soon after publishing his work on special relativity, Einstein began working to extend the theory to gravitational fields; he then published a paper on general relativity in 1916, introducing his theory of gravitation. He continued to deal with problems of statistical mechanics and quantum theory, which led to his explanations of particle theory and the motion of molecules. He also investigated the thermal properties of light and the quantum theory of radiation, the basis of the laser, which laid the foundation of the photon theory of light. In 1917, he applied the general theory of relativity to model the structure of the universe.

In 1933, while Einstein was visiting the United States, Adolf Hitler came to power. Because of his Jewish background, Einstein did not return to Germany. He settled in the United States and became an American citizen in 1940. On the eve of World War II, he endorsed a letter to President Franklin D. Roosevelt alerting FDR to the potential development of "extremely powerful bombs of a new type" and recommending that the US begin similar research. This eventually led to the Manhattan Project. Einstein supported the Allies, but he generally denounced the idea of using nuclear fission as a weapon. He signed the Russell–Einstein Manifesto with British philosopher Bertrand Russell, which highlighted the danger of nuclear weapons. He was affiliated with the Institute for Advanced Study in Princeton, New Jersey, until his death in 1955.

He published more than 300 scientific papers and more than 150 non-scientific works. His intellectual achievements and originality have made the word "Einstein" synonymous with "genius". Eugene Wigner compared him to his contemporaries, writing that "Einstein's understanding was deeper even than Jancsi von Neumann's. His mind was both more penetrating and more original".

Stamps from various countries depicting Albert Einstein

1929 Died: Ferdinand Foch, French field marshal (b. 1851)

Ferdinand Foch (2 October 1851 – 20 March 1929) was a French general and military theorist who served as the Supreme Allied Commander during the First World War. An aggressive, even reckless commander at the First Marne, Flanders, and Artois campaigns of 1914–1916, Foch became the Allied Commander-in-Chief in late March 1918 in the face of the all-out German spring offensive, which pushed the Allies back using fresh soldiers and new tactics that trenches could not contain. He successfully coordinated the French, British and American efforts into a coherent whole, deftly handling his strategic reserves. He stopped the German offensive and launched a war-winning counterattack. In November 1918, Marshal Foch accepted the German cessation of hostilities and was present at the armistice of 11 November.

Stamp issued in France for the war fund commemorating Ferdinand Foch

2004 Died: Juliana of the Netherlands (b. 1909)

Juliana; Juliana Louise Emma Marie Wilhelmina; (30 April 1909 – 20 March 2004) was Queen of the Netherlands from 1948 until her abdication in 1980.

Juliana was the only child of Queen Wilhelmina and Prince Henry of Mecklenburg-Schwerin. She received a private education and studied international law at the University of Leiden. In 1937, she married Prince Bernhard of Lippe-Biesterfeld with whom she had four daughters: Beatrix, Irene, Margriet, and Christina. During the German invasion of the Netherlands in the Second World War, the royal family was evacuated to the United Kingdom. Juliana then relocated to Canada with her children, while Wilhelmina and Bernhard remained in Britain. The royal family returned to the Netherlands after its liberation in 1945.

Due to Wilhelmina's failing health, Juliana took over royal duties briefly in 1947 and 1948. In September 1948 Wilhelmina abdicated and Juliana ascended to the Dutch throne. Her reign saw the decolonization and independence of the Dutch East Indies (now Indonesia) and Suriname. Despite a series of controversies involving the royal family, Juliana remained a popular figure among the Dutch.

In April 1980, Juliana abdicated in favor of her eldest daughter Beatrix. Upon her death in 2004 at the age of 94, she was the longest-lived former reigning monarch in the world.

Stamps from the Netherlands depicting Juliana

March 19th in stamps David Livingstone, Wyatt Earp, Auguste and Louis Lumière record their first footage using their newly patented cinematograph

Here are some events that happened on March 19th. It could be an event or a person that died or was born on that day

1813 Born: David Livingstone, Scottish missionary and explorer (d. 1873)

David Livingstone (19 March 1813 – 1 May 1873) was a Scottish physician, Congregationalist, and pioneer Christian missionary with the London Missionary Society, an explorer in Africa, and one of the most popular British heroes of the late 19th-century Victorian era. He had a mythic status that operated on a number of interconnected levels: Protestant missionary martyr, working-class "rags-to-riches" inspirational story, scientific investigator and explorer, imperial reformer, anti-slavery crusader, and advocate of British commercial and colonial expansion.

Livingstone's fame as an explorer and his obsession with learning the sources of the Nile River was founded on the belief that if he could solve that age-old mystery, his fame would give him the influence to end the East African Arab-Swahili slave trade. "The Nile sources," he told a friend, "are valuable only as a means of opening my mouth with power among men. It is this power which I hope to remedy an immense evil.":289 His subsequent exploration of the central African watershed was the culmination of the classic period of European geographical discovery and colonial penetration of Africa. At the same time, his missionary travels, "disappearance", and eventual death in Africa‍—‌and subsequent glorification as a posthumous national hero in 1874‍—‌led to the founding of several major central African Christian missionary initiatives carried forward in the era of the European "Scramble for Africa".

Stamp from Great Britain depicting  David Livingstone

1848 Born: Wyatt Earp, American police officer (d. 1929)

Wyatt Berry Stapp Earp (March 19, 1848 – January 13, 1929) was an American Old West lawman and gambler in Cochise County, Arizona Territory, and a deputy marshal in Tombstone. He worked in a wide variety of trades throughout his life and took part in the famous gunfight at the O.K. Corral, during which lawmen killed three outlaw Cochise County Cowboys. He is often erroneously regarded as the central figure in the shootout, although his brother Virgil was Tombstone city marshal and deputy U.S. marshal that day and had far more experience as a sheriff, constable, marshal, and soldier in combat.

Earp was also a professional gambler, teamster, and buffalo hunter, and he owned several saloons, maintained a brothel, mined for silver and gold, and refereed boxing matches. He spent his early life in Pella, Iowa. In 1870, he married Urilla Sutherland who contracted typhoid fever and died shortly before their first child was to be born. During the next two years, Earp was arrested for stealing a horse, escaped from jail, and was sued twice. He was arrested and fined three times in 1872 for "keeping and being found in a house of ill-fame". His third arrest was described at length in the Daily Transcript, which referred to him as an "old offender" and nicknamed him the "Peoria Bummer", another name for loafer or vagrant.

By 1874, he arrived in the boomtown of Wichita, Kansas, where his reputed wife opened a brothel. On April 21, 1875, he was appointed to the Wichita police force and developed a solid reputation as a lawman, but he was fined and dismissed from the force after getting into a fistfight with a political opponent of his boss. Earp immediately left Wichita, following his brother James to Dodge City, Kansas, where he became an assistant city marshal. In the winter of 1878, he went to Texas to track down an outlaw, and he met John "Doc" Holliday whom Earp credited with saving his life.

Earp moved constantly throughout his life from one boomtown to another. He left Dodge City in 1879 and moved with brothers James and Virgil to Tombstone, where a silver boom was underway. The Earps clashed with an informal group of outlaws known as the "Cowboys". Wyatt, Virgil, and their younger brother Morgan held various law-enforcement positions which put them in conflict with Tom McLaury, Frank McLaury, Ike Clanton, and Billy Clanton who threatened to kill the Earps on several occasions. The conflict escalated over the next year, culminating in the shoot out at the O.K. Corral on October 26, 1881, in which the Earps and Doc Holliday killed three of the Cowboys. In the next five months, Virgil was ambushed and maimed, and Morgan was assassinated. Wyatt, Warren Earp, Doc Holliday, and others formed a federal posse which killed three of the Cowboys whom they thought responsible. Wyatt was never wounded in any of the gunfights, unlike his brothers Virgil and Morgan or his friend Doc Holliday, which only added to his mystique after his death.

Earp was a lifelong gambler and was always looking for a quick way to make money. After leaving Tombstone, he went to San Francisco where he reunited with Josephine Marcus, and she became his common-law wife. They joined a gold rush to Eagle City, Idaho, where they owned mining interests and a saloon. They left there to race horses and open a saloon during a real estate boom in San Diego, California. Back in San Francisco, Wyatt raced horses again, but his reputation suffered irreparably when he refereed the Fitzsimmons vs. Sharkey boxing match and called a foul which led many to believe that he fixed the fight. They moved briefly to Yuma, Arizona, before joining the Nome Gold Rush in 1899. He and Charlie Hoxie paid $1,500 (about $51,000 in 2018) for a liquor license to open a two-story saloon called the Dexter and made an estimated $80,000 (about $2 million in 2017 dollars). The couple then left Alaska and opened another saloon in Tonopah, Nevada, the site of a new gold find. Around 1911, Earp began working several mining claims in Vidal, California, retiring in the hot summers with Josephine to Los Angeles. He made friends among early Western actors in Hollywood and tried to get his story told, but he was portrayed only very briefly in one film produced during his lifetime: Wild Bill Hickok (1923).

Earp died on January 13, 1929. He was known as a Western lawman, gunfighter, and boxing referee. He had a notorious reputation for both his handling of the Fitzsimmons–Sharkey fight and his role in the O.K. Corral gunfight. This only began to change after his death when the extremely flattering biography Wyatt Earp: Frontier Marshal was published in 1931. It became a bestseller and created his reputation as a fearless lawman. Since then, Earp has been the subject of numerous films, television shows, biographies, and works of fiction which have increased both his fame and his notoriety. Long after his death, he has many devoted detractors and admirers. His modern-day reputation is that of the Old West's toughest and deadliest gunman.

US stamp and First Day Cover depicting Wyatt Earp

1895 – Auguste and Louis Lumière record their first footage using their newly patented cinematograph.

The Lumière brothers (Auguste Marie Louis Nicolas; 19 October 1862 – 10 April 1954) and Louis Jean (5 October 1864 – 7 June 1948), were among the first filmmakers in history. They patented an improved cinematograph, which in contrast to Thomas Edison's "peepshow" kinetoscope allowed simultaneous viewing by multiple parties.

When their father retired in 1892, the brothers began to create moving pictures. They patented several significant processes leading up to their film camera, most notably film perforations (originally implemented by Emile Reynaud) as a means of advancing the film through the camera and projector. The original cinématographe had been patented by Léon Guillaume Bouly on 12 February 1892. The brothers patented their own version on 13 February 1895. The first footage ever to be recorded using it was recorded on 19 March 1895. This first film shows workers leaving the Lumière factory.

The Lumière brothers saw film as a novelty and had withdrawn from the film business in 1905. They went on to develop the first practical photographic colour process, the Lumière Autochrome.

Louis died on 6 June 1948 and Auguste on 10 April 1954. They are buried in a family tomb in the New Guillotière Cemetery in Lyon.

French stamp depicting Auguste and Louis Lumière

March 18th in stamp Miloš Obrenović, Rudolf Diesel, Mohandas Gandhi is sentenced to six years in prison, Randal Cremer

Here are some events that happened on March 18th. It could be an event or a person that died or was born on that day

1780 Born: Miloš Obrenović, Serbian prince (d. 1860)

Prince Miloš Obrenović I of Serbia (18 March 1780 or 1783 – 26 September 1860) born Miloš Teodorović was Prince of Serbia from 1815 to 1839, and again from 1858 to 1860. He participated in the First Serbian uprising, led Serbs in the Second Serbian uprising, and founded the House of Obrenović. Under his rule, Serbia became an autonomous principality within the Ottoman Empire. Prince Miloš ruled autocratically, consistently refusing to share power, which generated strong domestic opposition. During his rule, Miloš I bought a number of estates and ships from Ottoman Turks and also became a prominent trader. He was the richest man in Serbia and one of the richest in the Balkans, with estates in Vienna, Serbia and Wallachia.

Serbian stamps depicting Miloš Obrenović

1828 Born: Randal Cremer, English activist and politician, Nobel Prize laureate (d. 1908)

Sir William Randal Cremer (18 March 1828 – 22 July 1908) usually known by his middle name "Randal", was an English Liberal Member of Parliament, a pacifist, and a leading advocate for international arbitration. He was awarded the Nobel Peace Prize in 1903 for his work with the international arbitration movement.

From as early as his first unsuccessful run for Parliament in 1868, Cremer had advocated the expansion of international arbitration as peaceful alternative to war for the resolution of disputes.

He was elected as Liberal Member of Parliament (MP) for Haggerston in the Shoreditch district of Hackney from 1885 to 1895, and then from 1900 until his death from pneumonia in 1908.

Using his platform as an MP, Cremer cultivated allies on both continental Europe and across the Atlantic, including Frédéric Passy, William Jennings Bryan and Andrew Carnegie. Using his network of contacts and his talent for organisation, Cremer did much to create and expand institutions for international arbitration, which during his lifetime were successful in peacefully resolving numerous international disputes. This work includes co-founding the Inter-Parliamentary Union and the International Arbitration League; gaining acceptance for the 1897 Olney–Pauncefote Treaty between the United States and Britain that would have required arbitration of major disputes as the Essequibo territory (the treaty was rejected by the US Senate and never went into effect); and preparing the ground for the Hague peace conferences of 1899 and 1907.

In recognition of his work in the arbitration movement, Cremer won the Nobel Peace Prize, the first to do so solo, in 1903. Of the £8,000 award he donated £7,000 as an endowment for the International Arbitration League.

He also was named a Chevalier of the French Légion d'honneur, won the Norwegian Knighthood of Saint Olaf and was knighted in 1907.

Stamp issued by Guinea Bissau depicting Randal Cremer

1858 Born: Rudolf Diesel, German engineer, invented the Diesel engine (d. 1913)

Rudolf Christian Karl Diesel (18 March 1858 – 29 September 1913) was a German inventor and mechanical engineer, famous for the invention of the Diesel engine, and for his suspicious death at sea.

In early 1890, Diesel moved to Berlin with his wife and children, Rudolf Jr, Heddy, and Eugen, to assume management of Linde's corporate research and development department and to join several other corporate boards there. As he was not allowed to use the patents he developed while an employee of Linde's for his own purposes, he expanded beyond the field of refrigeration. He first worked with steam, his research into thermal efficiency and fuel efficiency leading him to build a steam engine using ammonia vapour. During tests, however, the engine exploded and almost killed him. His research into high compression cylinder pressures tested the strength of iron and steel cylinder heads. One exploded during a run in. He spent many months in a hospital, followed by health and eyesight problems.

Ever since attending lectures of Carl von Linde, Diesel intended designing an internal combustion engine that could approach the maximum theoretical thermal efficiency of the Carnot cycle. He worked on this idea for several years, and in 1892, he considered his theory to be completed. The same year, Diesel was given the German patent DRP 67207. In 1893, he published a treatise entitled Theory and Construction of a Rational Heat-engine to Replace the Steam Engine and The Combustion Engines Known Today, that he had been working on since early 1892. This treatise formed the basis for his work on and invention of the Diesel engine. By summer 1893, Diesel had realised that his initial theory was erroneous, which led him to file another patent application for the corrected theory in 1893.

Diesel understood thermodynamics and the theoretical and practical constraints on fuel efficiency. He knew that as much as 90% of the energy available in the fuel is wasted in a steam engine. His work in engine design was driven by the goal of much higher efficiency ratios. In his engine, fuel was injected at the end of the compression stroke and was ignited by the high temperature resulting from the compression. From 1893 to 1897, Heinrich von Buz, director of MAN SE in Augsburg, gave Rudolf Diesel the opportunity to test and develop his ideas.

The first successful Diesel engine ran in 1897 and is now on display at the German Technical Museum in Munich.

Rudolf Diesel obtained patents for his design in Germany and other countries, including the United States.

He was inducted into the Automotive Hall of Fame in 1978.

Stamps from Germany and Saarland depicting Diesel

1922 – In India, Mohandas Gandhi is sentenced to six years in prison for civil disobedience, of which he serves only two.

Mohandas Karamchand Gandhi (2 October 1869 – 30 January 1948) was an Indian lawyer, anti-colonial nationalist, and political ethicist, who employed nonviolent resistance to lead the successful campaign for India's independence from British Rule, and in turn inspire movements for civil rights and freedom across the world. The honorific Mahātmā (Sanskrit: "great-souled", "venerable"), first applied to him in 1914 in South Africa, is now used throughout the world.

Born and raised in a Hindu family in coastal Gujarat, western India, Gandhi was trained in law at the Inner Temple, London, and called to the bar at age 22 in June 1891. After two uncertain years in India, where he was unable to start a successful law practice, he moved to South Africa in 1893 to represent an Indian merchant in a lawsuit. He went on to stay for 21 years. It was in South Africa that Gandhi raised a family, and first employed nonviolent resistance in a campaign for civil rights. In 1915, aged 45, he returned to India. He set about organizing peasants, farmers, and urban laborers to protest against excessive land-tax and discrimination. Assuming leadership of the Indian National Congress in 1921, Gandhi led nationwide campaigns for easing poverty, expanding women's rights, building religious and ethnic amity, ending untouchability, and above all for achieving Swaraj or self-rule.

The same year Gandhi adopted the Indian loincloth, or short dhoti and, in the winter, a shawl, both woven with yarn hand-spun on a traditional Indian spinning wheel, or charkha, as a mark of identification with India's rural poor. Thereafter, he lived modestly in a self-sufficient residential community, ate simple vegetarian food, and undertook long fasts as a means of self-purification and political protest. Bringing anti-colonial nationalism to the common Indians, Gandhi led them in challenging the British-imposed salt tax with the 400 km (250 mi) Dandi Salt March in 1930, and later in calling for the British to Quit India in 1942. He was imprisoned for many years, upon many occasions, in both South Africa and India.

Gandhi's vision of an independent India based on religious pluralism was challenged in the early 1940s by a new Muslim nationalism which was demanding a separate Muslim homeland carved out of India. In August 1947, Britain granted independence, but the British Indian Empire was partitioned into two dominions, a Hindu-majority India and Muslim-majority Pakistan. As many displaced Hindus, Muslims, and Sikhs made their way to their new lands, religious violence broke out, especially in the Punjab and Bengal. Eschewing the official celebration of independence in Delhi, Gandhi visited the affected areas, attempting to provide solace. In the months following, he undertook several fasts unto death to stop religious violence. The last of these, undertaken on 12 January 1948 when he was 78, also had the indirect goal of pressuring India to pay out some cash assets owed to Pakistan. Some Indians thought Gandhi was too accommodating.  Among them was Nathuram Godse, a Hindu nationalist, who assassinated Gandhi on 30 January 1948 by firing three bullets into his chest

Stamps from various countries depicting Gandhi

March 17th in stamps Gottlieb Daimler, William II, Christian Doppler, Nat King Cole

Here are some events that happened on March 17th. It could be an event or a person that died or was born on that day

1834 Born: Gottlieb Daimler, German engineer and businessman, co-founded Daimler-Motoren-Gesellschaft (d. 1900)

Gottlieb Wilhelm Daimler (17 March 1834 – 6 March 1900) was an engineer, industrial designer and industrialist born in Schorndorf (Kingdom of Württemberg, a federal state of the German Confederation), in what is now Germany. He was a pioneer of internal-combustion engines and automobile development. He invented the high-speed liquid petroleum-fuelled engine.

Daimler and his lifelong business partner Wilhelm Maybach were two inventors whose goal was to create small, high-speed engines to be mounted in any kind of locomotion device. In 1883 they designed a horizontal cylinder layout compressed charge liquid petroleum engine that fulfilled Daimler's desire for a high speed engine which could be throttled, making it useful in transportation applications. This engine was called Daimler's Dream.

In 1885 they designed a vertical cylinder version of this engine which they subsequently fitted to a two-wheeler, the first internal combustion motorcycle which was named the Petroleum Reitwagen (Riding Car) and, in the next year, to a coach, and a boat. Daimler called this engine the grandfather clock engine (Standuhr) because of its resemblance to a large pendulum clock.

In 1890, they converted their partnership into a stock company Daimler Motoren Gesellschaft (DMG, in English—Daimler Motors Corporation). They sold their first automobile in 1892. Daimler fell ill and took a break from the business. Upon his return he experienced difficulty with the other stockholders that led to his resignation in 1893. This was reversed in 1894. Maybach resigned at the same time, and also returned. In 1900 Daimler died and Wilhelm Maybach quit DMG in 1907.

German and Hungarian stamps depicting Gottlieb Daimler or his cars

1849 Died: William II, Dutch sovereign prince and king (b. 1792)

William II (Willem Frederik George Lodewijk, anglicized as William Frederick George Louis; 6 December 1792 – 17 March 1849) was King of the Netherlands, Grand Duke of Luxembourg, and Duke of Limburg.

William II was the son of William I and Wilhelmine of Prussia. When his father, who up to that time ruled as sovereign prince, proclaimed himself king in 1815, he became Prince of Orange as heir apparent of the Kingdom of the Netherlands. With the abdication of his father on 7 October 1840, William II became king. During his reign, the Netherlands became a parliamentary democracy with the new constitution of 1848.

William II was married to Anna Pavlovna of Russia. They had four sons and one daughter. William II died on 17 March 1849 and was succeeded by his son William III.

Dutch stamps from 1913 depicting Willem II

1853 Died: Christian Doppler, Austrian physicist and mathematician (b. 1803)

Christian Andreas Doppler (29 November 1803 – 17 March 1853) was an Austrian mathematician and physicist. He is celebrated for his principle – known as the Doppler effect – that the observed frequency of a wave depends on the relative speed of the source and the observer. He used this concept to explain the color of binary stars.

The Doppler effect (or the Doppler shift) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842.

A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, and lower during the recession.

The reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrivals of successive wave crests at the observer is reduced, causing an increase in the frequency. While they are traveling, the distance between successive wave fronts is reduced, so the waves "bunch together". Conversely, if the source of waves is moving away from the observer, each wave is emitted from a position farther from the observer than the previous wave, so the arrival time between successive waves is increased, reducing the frequency. The distance between successive wave fronts is then increased, so the waves "spread out".

For waves that propagate in a medium, such as sound waves, the velocity of the observer and of the source are relative to the medium in which the waves are transmitted. The total Doppler effect may therefore result from motion of the source, motion of the observer, or motion of the medium. Each of these effects is analyzed separately. For waves which do not require a medium, such as light or gravity in general relativity, only the relative difference in velocity between the observer and the source needs to be considered.

Austrian stamp depicting Doppler

1919 Born: Nat King Cole, American singer, pianist, and television host (d. 1965)

Nathaniel Adams Coles (March 17, 1919 – February 15, 1965), known professionally as Nat King Cole, was an American singer and jazz pianist. He recorded over 100 songs that became hits on the pop charts. His trio was the model for small jazz ensembles that followed. Cole also acted in films and on television and performed on Broadway. He was the first African-American man to host an American television series. He was the father of singer-songwriter Natalie Cole (1950–2015).

US stamp depicting Nat King Cole

February 28th in stamps Friedrich Ebert, Alfonso XIII of Spain

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1925 Died: Friedrich Ebert, German politician, 1st President of Germany (b. 1871)

Friedrich Ebert (4 February 1871 – 28 February 1925) was a German politician of the Social Democratic Party of Germany (SPD) and the first President of Germany from 1919 until his death in office in 1925.

Ebert was elected leader of the SPD on the death in 1913 of August Bebel. In 1914, shortly after he assumed leadership, the party became deeply divided over Ebert's support of war loans to finance the German war effort in World War I. A moderate social democrat, Ebert was in favour of the Burgfrieden, a political policy that sought to suppress squabbles over domestic issues among political parties during wartime in order to concentrate all forces in society on the successful conclusion of the war effort. He tried to isolate those in the party opposed to the war, but could not prevent a split.

Ebert was a pivotal figure in the German Revolution of 1918–19. When Germany became a republic at the end of World War I, he became its first chancellor. His policies at that time were primarily aimed at restoring peace and order in Germany and containing the more extreme elements of the revolutionary left. In order to accomplish these goals, he allied himself with conservative and nationalistic political forces, in particular the leadership of the military under General Wilhelm Groener and the right-wing Freikorps. With their help, Ebert's government crushed a number of socialist and communist uprisings as well as those from the right, including the Kapp Putsch, a legacy which has made him a controversial historical figure.

German stamps depicting Friedrich Ebert

1941 Died: Alfonso XIII of Spain (b. 1886)

Alfonso XIII (17 May 1886 – 28 February 1941), also known as El Africano or the African, was King of Spain from 1886 until the proclamation of the Second Republic in 1931. He was a monarch from birth as his father, Alfonso XII, had died the previous year. Alfonso's mother, Maria Christina of Austria, served as regent until he assumed full powers on his sixteenth birthday in 1902.

During Alfonso's reign of the Kingdom of Spain, the country experienced four major problems that contributed to the end of the liberal monarchy: the lack of real political representation of broad social groups; the poor situation of the popular classes, especially peasants; problems arising from the Rif War; and Catalan nationalism. The political and social turbulence that began with the Spanish–American War prevented the turnaround parties from establishing a true liberal democracy, which led to the establishment of the dictatorship of Miguel Primo de Rivera. With the political failure of the dictatorship, Alfonso impelled a return to the democratic normality with the intention of regenerating the regime. Nevertheless, it was abandoned by all political classes, as they felt betrayed by the king's support of the dictatorship of Primo de Rivera.

He left Spain voluntarily after the municipal elections of April 1931, which were taken as a plebiscite on abolishing the monarchy.

Spanish and Puerto Rico stamps depicting Alfonso XIII 

February 27th in stamps Lord Byron, John Steinbeck, Bayern München, Ivan Pavlov,

Here are some events that happened on February 27th. It could be an event or a person that died or was born on that day

1812 – Poet Lord Byron gives his first address as a member of the House of Lords, in defense of Luddite violence against Industrialism in his home county of Nottinghamshire.

George Gordon Byron, 6th Baron Byron (22 January 1788 – 19 April 1824), known simply as Lord Byron, was an English peer, who was a poet and politician. He was one of the leading figures of the Romantic movement and is regarded as one of the greatest English poets. He remains widely read and influential. Among his best-known works are the lengthy narrative poems Don Juan and Childe Harold's Pilgrimage; many of his shorter lyrics in Hebrew Melodies also became popular.

He travelled extensively across Europe, especially in Italy, where he lived for seven years in the cities of Venice, Ravenna, and Pisa. During his stay in Italy he frequently visited his friend and fellow poet Percy Bysshe Shelley. Later in life Byron joined the Greek War of Independence fighting the Ottoman Empire and died of disease leading a campaign during that war, for which Greeks revere him as a national hero. He died in 1824 at the age of 36 from a fever contracted after the First and Second Siege of Missolonghi.

His only marital child, Ada Lovelace, is regarded as a foundational figure in the field of computer programming based on her notes for Charles Babbage's Analytical Engine. Byron's extramarital children include Allegra Byron, who died in childhood, and possibly Elizabeth Medora Leigh, daughter of his half-sister Augusta Leigh.

Stamps from Greece, Hungary and Russia depicting Lord Byron

1900 – Fußball-Club Bayern München is founded.

Fußball-Club Bayern München e.V. commonly known as FC Bayern München, FCB, Bayern Munich, or FC Bayern, is a German professional sports club based in Munich, Bavaria. It is best known for its professional football team, which plays in the Bundesliga, the top tier of the German football league system, and is the most successful club in German football history, having won a record 30 national titles, including eight consecutively since 2013, and 20 national cups, along with numerous European honors.

FC Bayern Munich was founded in 1900 by 11 football players, led by Franz John. Although Bayern won its first national championship in 1932, the club was not selected for the Bundesliga at its inception in 1963. The club had its period of greatest success in the middle of the 1970s when, under the captaincy of Franz Beckenbauer, it won the European Cup three consecutive times (1974–1976). Overall, Bayern have reached eleven European Cup/UEFA Champions League finals, most recently winning their sixth title in 2020 as part of a continental treble. By winning their sixth Champions League trophy in 2020, Bayern became only the second European club in history to achieve the continental treble twice. Bayern has also won one UEFA Cup, one European Cup Winners' Cup, two UEFA Super Cups, one FIFA Club World Cup and two Intercontinental Cups, making it one of the most successful European clubs internationally and the only German club to have won both international titles. Since the formation of the Bundesliga, Bayern has been the dominant club in German football, winning 30 titles. The club has traditional local rivalries with 1860 Munich and 1. FC Nürnberg, as well as with Borussia Dortmund since the mid-1990s.

Since the beginning of the 2005–06 season, Bayern has played its home games at the Allianz Arena. Previously the team had played at Munich's Olympiastadion for 33 years. The team colors are red and white, and the team crest shows the white and blue flag of Bavaria. In terms of revenue, Bayern Munich is the largest sports club in Germany and the fourth highest-earning football club in the world, generating €660.1 million in 2020. For the 2018–19 season, Bayern reported a revenue of €750.4 million and an operating profit of €146.1 million. This was Bayern's 27th consecutive year with a profit. In November 2019, Bayern had 293,000 official members and there are 4,499 officially registered fan clubs with over 358,151 members. The club has other departments for chess, handball, basketball, gymnastics, bowling, table tennis and senior football with more than 1,100 active members. At the end of the 2019–20 season, Bayern was ranked first in the UEFA club coefficient rankings.

German stamps issued to commemorate Bayern München's successes

1902 Born: John Steinbeck, American journalist and author, Nobel Prize laureate (d. 1968)

John Ernst Steinbeck Jr. (February 27, 1902 – December 20, 1968) was an American author and the 1962 Nobel Prize in Literature winner "for his realistic and imaginative writings, combining as they do sympathetic humour and keen social perception." He has been called "a giant of American letters," and many of his works are considered classics of Western literature.

During his writing career, he authored 33 books, with one book coauthored alongside Edward Ricketts, including 16 novels, six non-fiction books, and two collections of short stories. He is widely known for the comic novels Tortilla Flat (1935) and Cannery Row (1945), the multi-generation epic East of Eden (1952), and the novellas The Red Pony (1933) and Of Mice and Men (1937). The Pulitzer Prize-winning The Grapes of Wrath (1939) is considered Steinbeck's masterpiece and part of the American literary canon. In the first 75 years after it was published, it sold 14 million copies.

Most of Steinbeck's work is set in central California, particularly in the Salinas Valley and the California Coast Ranges region. His works frequently explored the themes of fate and injustice, especially as applied to downtrodden or everyman protagonists.

US stamp and FDC commemorating John Steinbeck

1936 Died: Ivan Pavlov, Russian physiologist and physician, Nobel Prize laureate (b. 1849)

Ivan Petrovich Pavlov (Russian: Ива́н Петро́вич Па́влов; 26 September 1849 – 27 February 1936) was a Russian physiologist known primarily for his work in classical conditioning.

From his childhood days Pavlov demonstrated intellectual curiosity along with an unusual energy which he referred to as "the instinct for research". Inspired by the progressive ideas which Dmitry Pisarev, a Russian literary critic of the 1860s, and Ivan Sechenov, the father of Russian physiology, were spreading, Pavlov abandoned his religious career and devoted his life to science. In 1870, he enrolled in the physics and mathematics department at the University of Saint Petersburg to study natural science.

Pavlov won the Nobel Prize for Physiology or Medicine in 1904, becoming the first Russian Nobel laureate. A survey in the Review of General Psychology, published in 2002, ranked Pavlov as the 24th most cited psychologist of the 20th century. Pavlov's principles of classical conditioning have been found to operate across a variety of behavior therapies and in experimental and clinical settings, such as educational classrooms and even reducing phobias with systematic desensitization.

Stamps from Hungary,  Romania, Argentina and Russia depicting Ivan Pavlov