Zahlen, bitte! Albert Einstein's 8-minute argument about the sun
Does the exploding sun affect the earth immediately or only after 8 minutes? Einstein created the General Theory of Relativity in 1915 to answer this question.
(Image: heise online)
In June 1915, Albert Einstein traveled from Berlin to Göttingen. There, at the invitation of mathematician David Hilbert, he gave six two-hour lectures at the university on his treatise "The Formal Basis of the General Theory of Relativity", which had been published in 1914.
The 53-year-old Hilbert had lively discussions with the young scientist, for example about the problem of what would happen to the earth if the sun exploded. Would it remain on its elliptical orbit for another 8 minutes or would it tumble into space at the same time? After the visit, Hilbert wrote a letter to Einstein saying that he had enjoyed his lectures very much and that he would now look into the mathematical foundations of this theory of relativity himself. Suddenly Einstein had serious competition.
At this time, Einstein himself had unhinged Newton's classical mechanics with his special theory of relativity in 1905: Time and space are not absolute constants, but relative. Time and space could be curved, depending on the mass of planets. Light is also subject to these gravitational fields.
Einstein seeks math tutoring
To finally prove his theory, the physicist Einstein needed mathematical tutoring in n-dimensional geometry, as the mathematician Bernhard Riemann had initiated with his considerations on curved spaces. He wrote to his friend Marcel Grossmann, who had meanwhile become a mathematics professor in Zurich: "Grossmann, you have to help me, otherwise I'll go mad." Grossmann helped, patiently explaining the basics of modern geometry to Einstein and correcting his calculations.
(Image:Â gemeinfrei, Ferdinand Schmutzer)
However, around 1914, when the first phase of the project was completed, Einstein distrusted his calculations. He was therefore interested in an exchange with David Hilbert, who was the leading German mathematician at the time. Another point: the First World War was raging and the pacifist Einstein, like Hilbert and Max Planck, had drawn up a memorandum that rejected the plans of the victory-minded annexationists in the war aims debate, who wanted to "bring Belgium home" to the Reich.
Einstein stayed at the hotel and discussed his ideas with the visitors to his lecture, including the concept of the exploding sun. According to Newtonian celestial mechanics, the Earth should immediately tumble out of its orbit without any time delay, while Einstein argued that space-time cannot be faster than the speed of light. When the sun loses its shape, the information takes several minutes of light to affect the earth.
Videos by heise
Competitor for the creation of the general theory of relativity
After his lectures in Göttingen, Einstein takes a vacation, initially on the island of Rügen. He writes to a friend: "I am very enthusiastic about Hilbert. An important man!" He then visits his wife, who is separated from him, in Switzerland. Finally, he receives a letter from Hilbert, who announces that he will be working on the theory of relativity himself. Einstein is now under enormous pressure to work out his theory of gravity and present it to the experts.
He worked feverishly until he was able to formulate ten equations based on his old calculations, which he presented to the Royal Prussian Academy of Sciences in November 1915 under the title "The Field Equations of Gravitation". The general theory of relativity is complete. "This finally completes the general theory of relativity as a logical edifice," Einstein concludes his lecture to the Academy on November 25. His lecture goes to press on December 2.
(Image:Â gemeinfrei)
Hilbert has also made it and presents his ideas in Göttingen on November 16. He sends Einstein, who is ill, a postcard with his ideas and sends the lecture to print on November 20. Einstein is anything but pleased with the development and grumbles to third parties that Hilbert has "nostrified" his theory.
Hilbert is not particularly pleased either, but gives priority to Einstein: "Every street urchin in Göttingen understands more about four-dimensional geometry than Einstein and yet he did the work and not the mathematicians." The two outstanding scientists soon got along again. When Einstein came to Göttingen, he was a guest of the Hilbert family. It was to take over 90 years for the dispute to escalate as to whether Hilbert plagiarized Einstein or Einstein plagiarized Hilbert, a dispute that escalated over the cut-up galley proofs of Hilbert's corrections to his essay.
Proof of the curvature of space through solar eclipse
Einstein sent the print of his lecture to friends in the Netherlands. The astronomer Wilhelm de Sitter forwarded it to the astrophysicist Arthur Eddington in Great Britain, who was very interested in Einstein's work on the theory of relativity. As Eddington wrote to Sitter, he prepared two expeditions in June 1916 that could confirm Einstein's theory of gravity. If a mass the size of the sun can bend space, then stars that are close to the sun as seen from Earth should appear displaced because the sun deflects the light beam.
This, in turn, would only be detectable during a solar eclipse, when the stars are visible at close range. For the solar eclipse of 29 May 1919, two expeditions from the western coast of Africa and from Brazil were supposed to be able to photograph these "neighbors", which succeeded despite a number of obstacles. "Einstein's theory triumphs," wrote the New York Times, "stars are not where they should be or where they were calculated to be, but no one should be afraid."
Empfohlener redaktioneller Inhalt
Mit Ihrer Zustimmung wird hier ein externes YouTube-Video (Google Ireland Limited) geladen.
Ich bin damit einverstanden, dass mir externe Inhalte angezeigt werden. Damit können personenbezogene Daten an Drittplattformen (Google Ireland Limited) übermittelt werden. Mehr dazu in unserer Datenschutzerklärung.
After these expeditions, at the latest, Einstein was certain that he would win the Nobel Prize. He bequeathed the prize money to his first wife and sons in his divorce settlement of 1919. In 1922, he was subsequently awarded the Nobel Prize for the year 1921 -- not for his theory(ies) of relativity, but for a paper that appeared in the "Annalen der Physik" on June 9, 1905.
120 years ago, in the essay "On a heuristic perspective concerning the generation and transformation of light", Einstein explained the nature of light, which moves in portions, so to speak. "During the propagation of a beam of light, energy is not continuously distributed over steadily increasing spaces, but consists of a limited number of energy quanta localized at points in space."
Numerous proofs of Einstein's theories have been found to date. The continuation of his ideas could manifest itself in a new theory that combines quantum mechanics of small particles with the theory of relativity of large masses. Perhaps this will make it possible to leap over the Big Bang and uncover the secret of dark energy, which Einstein described as a cosmological constant.
(dahe)
