Feb 14, 2024 08:51 PM
https://bigthink.com/starts-with-a-bang/...physicist/
KEY POINTS: Albert Einstein wasn't just a scientific revolutionary, he was a celebrity and cultural icon throughout most of his life in the 20th century. Famed for the relativity of motion, the constancy of the speed of light, E = mc², and winning the Nobel Prize for the photoelectric effect, he also brought us mind-bending ideas like wormholes and the EPR paradox. But it's his general theory of relativity, put forth in 1915, that sets him apart from everyone else in the minds of most professional physicists. Over 100 years later, it's still flawless.
EXCERPTS: . . . From this insight, special relativity was born, and with it, Newton’s laws of motion would only apply to non-relativistic motion, not to speeds approaching the speed of light.
But Einstein wasn’t done, not by a long shot. In 1907, his former professor Hermann Minkowski wove three-dimensional space and one-dimensional time into a four-dimensional fabric known as spacetime, where both space and time were relative to each observer, but a certain quantity — today known as the spacetime (or Einstein) interval — is always left invariant and unchanging. While thinking about an object’s motion through spacetime, Einstein had a realization that he would later call his “happiest thought:” the equivalence principle
[...] Einstein’s predictions were correct and in agreement with observations, while the Newtonian predictions were ruled out. At long last, we had a new theory of gravity to describe our Universe.
[...] Einstein’s general relativity, although an incredibly powerful theory, isn’t the easiest theory to work with or extract predictions from. It’s incredibly mathematically intensive to work with, and that makes extracting quantitative predictions difficult, to say the least. Furthermore, it’s very important that we model whatever physical system we’re considering correctly, in that we have to write down the correct spacetime for the problem we’re considering. (Which makes solving problems that much more difficult.) It’s why even though there are, theoretically, an infinite number of solutions to Einstein’s equations, there is only one physical Universe to apply them to.
Which is why it was such a surprise to everyone, Einstein included, when Georges Lemaître sent Einstein a letter in 1927, showing him that if you combined the spacetime solution for a Universe that was uniformly filled with matter-and-energy (which Einstein had erroneously called “incompatible” with his field equations in 1922) with the data for distances to and redshifts of galaxies, you could conclude that the Universe was expanding. Einstein did not believe this was possible, and retorted, “Vos calculs sont corrects, mais votre physique est abominable,” which translates to, “Your calculations are correct, but your physics is abominable.”
But Lemaître was correct, as Howard Robertson showed the next year and then Hubble showed more definitively the year after. The Universe really is expanding, and Einstein’s theory provided the theoretical explanation as to how, why, and by how much... (MORE - missing details)
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Lee Smolin: Physicists I've met who knew Einstein told me they found his thinking slow compared to the stars of the day. While he was competent enough with the basic mathematical tools of physics, many other physicists surrounding him in Berlin and Princeton were better at it. So what accounted for his genius?
In retrospect, I believe what allowed Einstein to achieve so much was primarily a moral quality. He simply cared far more than most of his colleagues that the laws of physics have to explain everything in nature coherently and consistently. As a result he was acutely sensitive to flaws and contradictions in the logical structure of physical theories.
Einstein's ability to see flaws and his fierce refusal to compromise had real repercussions. His professors did not support him in his search for an academic job and he was unemployed until he found work as a patent inspector. The problem was not just that he skipped classes. He saw right through his elders' complacent acceptance of Newtonian physics. The young Einstein was obsessed with logical flaws that were glaringly obvious, but only to him.
While the great English physicist Lord Rayleigh said he saw "only a few clouds on the horizon" remaining to be understood, the 16-year-old Einstein wondered what would happen to his image in a mirror if he traveled faster than the speed of light. --Einstein's Legacy: Where are the Einsteinians?
KEY POINTS: Albert Einstein wasn't just a scientific revolutionary, he was a celebrity and cultural icon throughout most of his life in the 20th century. Famed for the relativity of motion, the constancy of the speed of light, E = mc², and winning the Nobel Prize for the photoelectric effect, he also brought us mind-bending ideas like wormholes and the EPR paradox. But it's his general theory of relativity, put forth in 1915, that sets him apart from everyone else in the minds of most professional physicists. Over 100 years later, it's still flawless.
EXCERPTS: . . . From this insight, special relativity was born, and with it, Newton’s laws of motion would only apply to non-relativistic motion, not to speeds approaching the speed of light.
But Einstein wasn’t done, not by a long shot. In 1907, his former professor Hermann Minkowski wove three-dimensional space and one-dimensional time into a four-dimensional fabric known as spacetime, where both space and time were relative to each observer, but a certain quantity — today known as the spacetime (or Einstein) interval — is always left invariant and unchanging. While thinking about an object’s motion through spacetime, Einstein had a realization that he would later call his “happiest thought:” the equivalence principle
[...] Einstein’s predictions were correct and in agreement with observations, while the Newtonian predictions were ruled out. At long last, we had a new theory of gravity to describe our Universe.
[...] Einstein’s general relativity, although an incredibly powerful theory, isn’t the easiest theory to work with or extract predictions from. It’s incredibly mathematically intensive to work with, and that makes extracting quantitative predictions difficult, to say the least. Furthermore, it’s very important that we model whatever physical system we’re considering correctly, in that we have to write down the correct spacetime for the problem we’re considering. (Which makes solving problems that much more difficult.) It’s why even though there are, theoretically, an infinite number of solutions to Einstein’s equations, there is only one physical Universe to apply them to.
Which is why it was such a surprise to everyone, Einstein included, when Georges Lemaître sent Einstein a letter in 1927, showing him that if you combined the spacetime solution for a Universe that was uniformly filled with matter-and-energy (which Einstein had erroneously called “incompatible” with his field equations in 1922) with the data for distances to and redshifts of galaxies, you could conclude that the Universe was expanding. Einstein did not believe this was possible, and retorted, “Vos calculs sont corrects, mais votre physique est abominable,” which translates to, “Your calculations are correct, but your physics is abominable.”
But Lemaître was correct, as Howard Robertson showed the next year and then Hubble showed more definitively the year after. The Universe really is expanding, and Einstein’s theory provided the theoretical explanation as to how, why, and by how much... (MORE - missing details)
- - - - - - - - - - - -
Lee Smolin: Physicists I've met who knew Einstein told me they found his thinking slow compared to the stars of the day. While he was competent enough with the basic mathematical tools of physics, many other physicists surrounding him in Berlin and Princeton were better at it. So what accounted for his genius?
In retrospect, I believe what allowed Einstein to achieve so much was primarily a moral quality. He simply cared far more than most of his colleagues that the laws of physics have to explain everything in nature coherently and consistently. As a result he was acutely sensitive to flaws and contradictions in the logical structure of physical theories.
Einstein's ability to see flaws and his fierce refusal to compromise had real repercussions. His professors did not support him in his search for an academic job and he was unemployed until he found work as a patent inspector. The problem was not just that he skipped classes. He saw right through his elders' complacent acceptance of Newtonian physics. The young Einstein was obsessed with logical flaws that were glaringly obvious, but only to him.
While the great English physicist Lord Rayleigh said he saw "only a few clouds on the horizon" remaining to be understood, the 16-year-old Einstein wondered what would happen to his image in a mirror if he traveled faster than the speed of light. --Einstein's Legacy: Where are the Einsteinians?
