How Albert Einstein Fought for European Peace and Theoretical Physics

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

About how science was closely intertwined with politics.

At the very beginning of the twentieth century, colossal discoveries were made in physics, a number of which belonged to Albert Einstein, the creator of the general theory of relativity.

Scientists were on the verge of a completely new view of the Universe, which required intellectual courage from them, a willingness to immerse themselves in theory and skills in dealing with a complex mathematical apparatus. The challenge was not accepted by everyone, and, as sometimes happens, scientific disputes were superimposed on political differences caused first by the First World War, then by Hitler's coming to power in Germany. Einstein was also a key figure around which spears were breaking.

Einstein against everyone

The outbreak of the First World War was accompanied by a patriotic upsurge among the population of the participating states, including scientists.

In Germany in 1914, 93 scientists and cultural figures, including Max Planck, Fritz Haber and Wilhelm Roentgen, published a manifesto expressing their full support for the state and the war it is waging: “We, representatives of German science and art, protest before the entire cultural world against the lies and slander with which our enemies are trying to pollute the just cause of Germany in the hard struggle for existence imposed on her. Without German militarism, German culture would have been destroyed a long time ago at its very inception. German militarism is a derivative of German culture, and it was born in a country that, like no other country in the world, has been subjected to predatory raids for centuries."

Nevertheless, there was a German scientist who spoke out sharply against such ideas. Albert Einstein published a response manifesto “To the Europeans” in 1915: “Never before has war so disturbed the interaction of cultures. It is the duty of Europeans, educated and of good will, not to let Europe succumb. However, this appeal, besides Einstein himself, was signed by only three people.

Einstein became a German scientist quite recently, although he was born in Germany. He graduated from school and university in Switzerland, and after that for almost ten years various universities in Europe refused to hire him. This was partly due to the way in which Einstein approached the request to consider his candidacy.

So, in a letter to Paul Drude, the creator of the electronic theory of metals, he first pointed out two errors contained in his theory, and only then asked to be hired.

As a result, Einstein had to get a job at the Swiss patent office in Bern, and only at the very end of 1909 was he able to get a position at the University of Zurich. And already in 1913, Max Planck himself, together with the future Nobel laureate in chemistry Walter Nernst, personally came to Zurich to persuade Einstein to accept German citizenship, move to Berlin and become a member of the Prussian Academy of Sciences and director of the Institute of Physics.

Einstein found his work at the patent office astonishingly productive from a scientific point of view. “When someone passed by, I would put my notes in a drawer and pretend to be doing patent work,” he recalled. The year 1905 went down in the history of science as annus mirabilis, "the year of miracles."

This year, the journal Annalen der Physik published four articles by Einstein, in which he was able to theoretically describe Brownian motion, explain, using the Planckian idea of light quanta, the photoeffect, or the effect of electrons escaping from a metal when it is irradiated with light (it was in such an experiment that J. J. Thomson discovered the electron), and make a decisive contribution to the creation of the special theory of relativity.

An amazing coincidence: the theory of relativity appeared almost simultaneously with the theory of quanta and just as unexpectedly and irrevocably changed the foundations of physics.

In the 19th century, the wave nature of light was firmly established, and scientists were interested in how the substance in which these waves propagate is arranged.

Despite the fact that no one has yet observed the ether (this is the name of this substance) directly, doubts that it exists and permeates the entire Universe did not arise: it was clear that the wave should propagate in some kind of elastic medium, by analogy with circles from a stone thrown on the water: the water surface at the point where the stone falls, begins to oscillate, and, since it is elastic, the oscillations are transmitted to neighboring points, from them to neighboring ones, and so on. After the discovery of atoms and electrons, the existence of physical objects that cannot be seen with the existing instruments did not surprise anyone either.

One of the simple questions that classical physics could not find an answer to was this: is the ether carried away by bodies moving in it? By the end of the 19th century, some experiments convincingly showed that the ether is completely carried away by moving bodies, while others, and no less convincingly, that it is only partially carried away.

Circles on the water are one example of a wave in an elastic medium. If the moving body does not carry the ether along, then the speed of light relative to the body will be the sum of the speed of light relative to the ether and the speed of the body itself. If it completely entrains the ether (as happens when moving in a viscous liquid), then the speed of light relative to the body will be equal to the speed of light relative to the ether and will not depend in any way on the speed of the body itself.

The French physicist Louis Fizeau showed in 1851 that the ether is partially carried away by the moving stream of water. In a series of experiments from 1880-1887, the Americans Albert Michelson and Edward Morley, on the one hand, confirmed Fizeau's conclusion with a higher accuracy, and on the other hand, they found out that the Earth, revolving around the Sun, completely entrains the ether with it, that is, the speed of light on The earth is independent of how it moves.

To determine how the Earth moves in relation to the ether, Michelson and Morley constructed a special instrument, an interferometer (see diagram below). The light from the source falls on the semitransparent plate, from where it is partially reflected into the mirror 1 and partially passes to the mirror 2 (the mirrors are at the same distance from the plate). The rays reflected from the mirrors then again fall on the semitransparent plate and from it together arrive at the detector, on which an interference pattern arises.

If the Earth moves relative to the ether, for example, in the direction of mirror 2, then the speed of light in the horizontal and vertical directions will not coincide, which should lead to a phase shift of the waves reflected from different mirrors on the detector (for example, as shown in the diagram, bottom right). In reality, no displacement was observed (see bottom left).

Einstein vs. Newton

In their attempts to understand the motion of the ether and the propagation of light in it, Lorentz and the French mathematician Henri Poincaré had to assume that the dimensions of moving bodies change in comparison with the dimensions of stationary ones, and, moreover, time for moving bodies flows more slowly. It's hard to imagine - and Lorentz treated these assumptions more like a mathematical trick than a physical effect - but they allowed for the reconciliation of mechanics, electromagnetic theory of light and experimental data.

Einstein, in two articles in 1905, was able, on the basis of these intuitive considerations, to create a coherent theory in which all these amazing effects are a consequence of two postulates:

• the speed of light is constant and does not depend on how the source and receiver move (and is equal to about 300,000 kilometers per second);
• for any physical system, physical laws act in the same way, regardless of whether it is moving without acceleration (at any speed) or at rest.

And he derived the most famous physical formula - E = mc²! In addition, because of the first postulate, the movement of the ether ceased to matter, and Einstein simply abandoned it - light can propagate in emptiness.

The time dilation effect, in particular, leads to the famous "paradox of twins". If one of the two twins, Ivan, goes on a spaceship to the stars, and the second, Peter, remains to wait for him on Earth, then after his return it will turn out that Ivan has aged less than Peter, since time on his fast-moving spaceship was flowing more slowly. than on Earth.

This effect, as well as other differences between the theory of relativity and ordinary mechanics, manifests itself only at a tremendous speed of motion, comparable to the speed of light, and therefore we never encounter it in everyday life. For ordinary speeds with which we meet on Earth, the fraction v / c (recall, c = 300,000 kilometers per second) is very little different from zero, and we return to the familiar and cozy world of school mechanics.

Nevertheless, the effects of the theory of relativity must be taken into account, for example, when synchronizing clocks on GPS satellites with terrestrial ones for accurate operation of the positioning system. In addition, the effect of time dilation is manifested in the study of elementary particles. Many of them are unstable and turn into others within a very short time. However, they usually move quickly, and due to this, the time before their transformation from the point of view of the observer is stretched, which makes it possible to register and study them.

The special theory of relativity arose from the need to reconcile the electromagnetic theory of light with the mechanics of rapidly (and with constant speed) moving bodies. After moving to Germany, Einstein completed his general theory of relativity (GTR), where he added gravity to electromagnetic and mechanical phenomena. It turned out that the gravitational field can be described as deformation by a massive body of space and time.

One of the consequences of general relativity is the curvature of the ray trajectory when light passes near a large mass. The first attempt at experimental verification of general relativity was to take place in the summer of 1914 when observing a solar eclipse in the Crimea. However, a team of German astronomers were interned in connection with the outbreak of the war. In a sense, this saved the reputation of general relativity, because at that moment the theory contained errors and gave an incorrect prediction of the angle of deflection of the beam.

In 1919, the English physicist Arthur Eddington, when observing a solar eclipse on Principe Island off the west coast of Africa, was able to confirm that the light of a star (it became visible due to the fact that the Sun did not eclipse it), passing by the Sun, deviates exactly at the angle predicted Einstein's equations.

Eddington's discovery made Einstein a superstar.

On November 7, 1919, in the midst of the Paris Peace Conference, when all attention seemed to be focused on how the world would exist after the First World War, the London newspaper The Times published an editorial: “A Revolution in Science: A New Theory of the Universe, Newton's ideas are defeated."

Reporters chased Einstein everywhere, pestering him with requests to explain the theory of relativity in a nutshell, and the halls where he gave public lectures were overcrowded (at the same time, judging by the reviews of his contemporaries, Einstein was not a very good lecturer; the audience did not understand the essence of the lecture, but still came to see the celebrity).

In 1921, Einstein, along with the English biochemist and future President of Israel, Chaim Weizmann, went on a lecture tour of the United States to raise funds to support Jewish settlements in Palestine. According to The New York Times, "Every seat at the Metropolitan Opera was taken, from the orchestra pit to the last row of the gallery, hundreds of people stood in the aisles."The newspaper's correspondent emphasized: "Einstein spoke German, but eager to see and hear a man who supplemented the scientific concept of the Universe with a new theory of space, time and motion, took all the seats in the hall."

Despite the success with the general public, the theory of relativity was accepted with great difficulty in the scientific community.

From 1910 to 1921, progressive-minded colleagues nominated Einstein for the Nobel Prize in physics ten times, but the conservative Nobel Committee refused each time, citing the fact that the theory of relativity had not yet received sufficient experimental confirmation.

After Eddington's expedition, this began to feel more and more scandalous, and in 1921, still not convinced, the members of the committee made an elegant decision - to award Einstein a prize, without mentioning the theory of relativity at all, namely: “For services to theoretical physics and, especially, for his discovery of the law of the photoelectric effect”.

Aryan physics versus Einstein

Einstein's popularity in the West provoked a painful reaction from colleagues in Germany, who found themselves practically isolated after the militant manifesto of 1914 and the defeat in the First World War. In 1921, Einstein was the only German scientist who received an invitation to the World Solvay Physics Congress in Brussels (which he, however, ignored in favor of a trip to the United States with Weizmann).

At the same time, despite ideological differences, Einstein managed to maintain friendly relations with most of his patriotic colleagues. But from the extreme right wing of college students and academics, Einstein has gained a reputation as a traitor who leads German science astray.

One of the representatives of this wing was Philip Leonard. Despite the fact that in 1905 Lenard received the Nobel Prize in physics for the experimental study of electrons produced by the photoelectric effect, he suffered all the time due to the fact that his contribution to science was not sufficiently recognized.

First, in 1893 he borrowed a discharge tube of his own manufacture to Roentgen, and in 1895 Roentgen discovered that the discharge tubes were emitting rays that were still unknown to science. Lenard believed that the discovery should at least be considered joint, but all the glory of the discovery and the Nobel Prize in physics in 1901 went to Roentgen alone. Lenard was indignant and declared that he was the mother of the rays, while Roentgen was only a midwife. At the same time, apparently, Roentgen did not use the Lenard tube in decisive experiments.

The discharge tube with which Lenard studied electrons in the photoelectric effect, and Roentgen discovered his radiation

The discharge tube with which Lenard studied electrons in the photoelectric effect, and Roentgen discovered his radiation

Secondly, Lenard was deeply offended by British physics. He disputed the priority of Thomson's discovery of the electron and accused the English scientist of incorrectly referring to his work. Lenard created a model of the atom, which can be considered the predecessor of Rutherford's model, but this was not properly noted. It is not surprising that Lenard called the British a nation of mercenary and deceitful traders, and the Germans, on the contrary, a nation of heroes, and after the outbreak of the First World War he proposed to arrange an intellectual continental blockade on Great Britain.

Third, Einstein was able to theoretically explain the photoelectric effect, and Lenard in 1913, even before the disagreements related to the war, even recommended him for a professorship. But the Nobel Prize for the discovery of the law of the photoelectric effect in 1921 was given to Einstein alone.

The early 1920s were generally a difficult time for Lenard. He clashed with enthusiastic leftist students and was publicly humiliated when, after the assassination of the liberal politician of Jewish origin and German Foreign Minister Walter Rathenau, he refused to lower the flag on the building of his institute in Heidelberg.

His savings, invested in government debt, were burned out by inflation, and in 1922 his only son died from the effects of malnutrition during the war. Lenard became inclined to think that the problems of Germany (including in German science) are the result of a Jewish conspiracy.

A close associate of Lenard at this time was Johannes Stark, the 1919 Nobel Prize winner in physics, also inclined to blame the machinations of the Jews for his own failures. After the war, Stark, in opposition to the liberal Physics Society, organized the conservative "German Professional Community of University Teachers", with the help of which he tried to control funding for research and appointments to scientific and teaching positions, but did not succeed. After an unsuccessful defense of a graduate student in 1922, Stark declared that he was surrounded by admirers of Einstein, and resigned as a professor at the university.

In 1924, six months after the Beer Putsch, the Grossdeutsche Zeitung published an article by Lenard and Stark, "Hitler's Spirit and Science." The authors compared Hitler with such giants of science as Galileo, Kepler, Newton and Faraday (“What a blessing that this genius in the flesh lives among us!”), And also praised the Aryan genius and condemned Judaism that was corrupting him.

According to Lenard and Stark, in science, the pernicious Jewish influence manifested itself in new directions of theoretical physics - quantum mechanics and the theory of relativity, which demanded a rejection of old concepts and used a complex and unfamiliar mathematical apparatus.

For older scientists, even those as talented as Lenard, this was a challenge that few were able to accept.

Lenard contrasted "Jewish", that is, theoretical, physics with "Aryan", that is, experimental, and demanded that German science focus on the latter. In the preface to the textbook "German Physics" he wrote: "German physics? - people will ask. I could also say Aryan physics, or the physics of the Nordic people, the physics of truth-seekers, the physics of those who founded scientific research."

For a long time, the "Aryan physics" of Lenard and Stark remained a marginal phenomenon, and physicists of various origins were engaged in theoretical and experimental research of the highest level in Germany.

That all changed when Adolf Hitler became Chancellor of Germany in 1933. Einstein, who was at that time in the United States, renounced German citizenship and membership in the Academy of Sciences, and Academy President Max Planck welcomed this decision: "Despite the deep chasm that divides our political views, our personal friendships will always remain unchanged," he assured he is Einstein's personal correspondence. At the same time, some members of the academy were annoyed that Einstein had not been demonstratively expelled from it.

Soon Johannes Stark became president of the Institute of Physics and Technology and the German Research Society. Over the next year, a quarter of all physicists and half of theoretical physicists left Germany.