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Sottile e il Signore...: la scienza e la vita di Albert Einstein (1982)

di Abraham Pais

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591639,826 (4)6
A biography of Albert Einstein, told through various scientific and technical correspondences, including those with Michele Besso. Pais discusses the world of physics before Einstein, during Einstein's time and the impact on the scientific world after his death.
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This is my third re-read of this masterful take on Einstein’s work and life, beginning in the mid-90s. After all these years is still unsurpassed.

A few notes this time round.

One thing I always liked to demonstrate the 4-dimensionality of spacetime is a thought experiment: If you describe the motion of an apple with a 3-dimensional vector (up/down, left/right and forward/back), then when it's at relative rest, the direction of that vector is undefined. Stopping an object shouldn't break the math behind physics, nor should it leave us with a hidden direction variable - so something else has to be going on. Adding a fourth dimension means that when at rest in 3-space, the object is at maximum speed in the fourth dimension - time. Speeding up in one of the other 3 space dimensions necessarily means slowing down in the time direction, and you no longer need to use the magnitude of the vector to describe speed, it can be used for energy instead - plus the orthogonal space directions to the object's own time direction are no longer tied to the observer's space directions, so even time rate and dimensional length can change with the object's relative speed - therefore you get all the effects of Special Relativity for free (That is a good analogy, though it can be slightly misleading if we're not careful to remember (as best we can) to apply hyperbolic intuition to the time dimensionality of the analogy). In fact it gets even cooler when you accept time is just another direction - because it means moving entirely in a space direction is the fastest you can go - it’s instantaneously fast, you transition through every point on the topological countour of the universe in the direction of your travel in an instant. To everyone else though, it appears you move at the speed of light, because as you rotated your direction vector, you also rotated your space vector into the time domain. Meaning that you no longer experience the universe as being spacelike in the direction of your travel (it shrinks, a la length contraction), you experience it as timelike (the trailing clock leads) - because of this, even though you according to you, you made the trip across the universe in an instant, when you arrive, the universe disagrees and at your destination, clocks have moved forward by a number of seconds - the number of meters you travelled divided by conversion factor c to get seconds. This also happens to a lesser degree at subluminal speeds, and you can intuit to what degree using trigonometry.

To get the angle from the speed, simply perform an inverse sine - given the limitations of text I’ll call it “asin” - and to get the Lorentz factor for time dilation and length contraction etc, simply take the cosine, and invert it. So 1/cos(asin(v/c)). Turns out this is 100% equivalent to the Lorentz factor mostly taught, just way more intuitive.

It should be noted that special relativity is special for a reason: for one "speed through the time dimension" doesn't make much sense as speed is a space changing in time. As in a distance travelled in a certain amount of time. We could go more generally and say "rate of change" but it’s always "the rate of change" of some property with respect to something else. If a "spatial" speed is the rate of change of space with respect to time, what is changing with respect to what in a "temporal" speed? Now you would be tempted to say "time is change with respect to space" but that's actually what is said to be happening inside a blackhole, objects "at rest" are very much not inside blackholes. “c” is actually the speed of (c)ausality, its the speed at which point a is able to affect point b. as in if i had a cosmic base ball bat to swing at pluto I can't hit Pluto faster than it takes light to reach it. "Objects "at rest" are very much not inside blackholes." I don't think black hole interiors can violate the Equivalence Principal. I could be wrong (I don't think anyone actually knows), but in theory everything in a black hole should be just as much at rest as anything else, provided we don't use the classical definition of rest. Similarly, any vector between two Minkowski events must normalize to c in order to fit within a Lorenz equation (which inherently creates the speed of causality). In a spacetime diagram, in order to change your degree of orientation in x, you must remove orientation in y, z, or t. Time is change with respect to space, provided we don't use the classical definition of velocity and acceleration. Inside a black hole, we are perhaps flipping the classical definition of speed, distance over time, turning it into time over distance, but once again, that's only referring to speed if we use speed in the classical sense, a ratio of distance and time.

Re-reading this almost 30 years on, the way Pais goes into on the development of GR is still top-notch. Most GR textbooks nowadays give the impression that Einstein came up with SR, realized that light should bend around the sun, and then went to sleep for several years before finally coming out with GR fully formed. I found the discussion of all the false starts very interesting, not least because it makes Einstein look more human. I also took notice this time round how it leads you through the thought process behind the development of GR. This book is at the perfect level for someone who has just taken a really good undergrad quantum sequence – you can see how the giants of the field tried to quantize radiation, and why all the things that seem like common sense at first glance don’t work well. Another great and counter-intuitive aspect of Pais’ book his argument that Einstein’s work on quantum physics was his most radical and important contribution to physics, and hence that his Nobel Prize was actually, if unintentionally, given for his most important work. According to Pais’ interpretation, Einstein’s opposition to the quantum mechanics arose precisely because he was the first person to fully appreciate just how strange and revolutionary quantum physics actually is. Hands down the best science book ever written for the laymen and laywoman. Back in the day we used a lot of tensor calculus in special relativity and it was (still is) kinda cool to see another approach for introducing them. If you however are not really satisfied with Pedro G. Ferreira’s take on Einstein’s work (and life), review to follow later on, and want a deeper mathematical understanding than "tensors are objects that behave like tensors", I would heartily recommend Pais’ book. He explains perfectly what tensors are in regard, to space, dual space and the tensor product and why they transform as they do, what the metric tensor does and why etc. It is still depressing to see that the greatest number of comments on Pais’ book on social media are inane sophomoric humor rather than scholarly discussions. It makes me wonder how many readers came to the site expecting another watered down science book filled with cute drawings and bombastic commentary about falling into Black Holes. Surprise!!! It's a college book! Abraham Pais was the real shit! ( )
  antao | Jul 26, 2021 |
Subtle is the Lord is a biography of Albert Einstein by Abraham Pais. It brilliantly tells the story of Einstein and his development into a world-renowned Physicist. While covering his life, the book also covers the work that Einstein did in Physics. Starting with his youth and childhood, Subtle is the Lord addresses the theories of Einstein being bad in school by presenting his report card. Although it is true that Einstein didn’t particularly like the authoritative atmosphere of his school, he did not get terrible marks. He taught himself Differential and Integral Calculus by the time he was 16 or so and was wonderful at math.

While Einstein might have had some professional stumbling blocks, most people can agree that 1905 was the year for Einstein. He published six papers that year, with one of them gaining him the Nobel Prize and the others firmly planting him in the upper echelons of physicists. The six papers are:
(1. The light-quantum and the Photoelectric Effect. This one led to the Nobel Prize and was completed on March 17.
(2. A new determination of molecular dimensions, completed April 30. This one became his doctoral thesis and was quoted quite often.
(3. Brownian Motion, received May 11. A direct outgrowth of his thesis work.
(4. The first paper on Special Relativity, received June 30.
(5. The second paper on Special Relativity, containing E = mc^2 received September 27.
(6. The second paper on Brownian Motion, received December 19.

I particularly like the book because it doesn’t shy away from the Mathematics of Einstein’s theories. It discusses the ideas behind the things he developed and shows the state of affairs for each thing beforehand. For instance, before 1905 Einstein published some papers that he felt were lacking once he discovered the works of Gibbs and Boltzmann. It talks about his work on Brownian Motion, his work on the Photoelectric Effect, Special and General Relativity and many of the other things that he had a hand in. With Pais being a Physicist himself, he is able to explain the equations and what they mean.

This particular copy of Subtle is the Lord was printed in 1982, so it does not have further developments on Einstein’s theories and how they are accepted or denied now. ( )
  Floyd3345 | Jun 15, 2019 |
One of the best books about Einstein. ( )
1 vota hcubic | Jan 30, 2013 |
ספר מרשים ביותר בעומק הידע הפיזיקלי וההיסטורי המופגן בו ובכמות המחקר שהושקעה בו. נראה שהמחבר קרא והבין כל פיסת נייר שנעתבו על ידי או על איינשטיין. מרתק לעתים - בעיקר בגלל העניין העצום באדם עצמו ובנושאים המטופלים. ם זאת גם מעורר תמיהות ומשאיר בלתי מסופק מכמה בחינות. א. חוסר הארגון משונה. שילוב של ביוגרפיה כרונולוגיצ עם ביגורפיה מדעית המסודרת לפי נושאים. ב. למי זה מיועד - יש כאן הרבה מאוד פיזיק מבלי להסביר אפילו מושגים מתקדמים. רק פיזיקאים מקצועיים יכולים להבין את הכל וחבל. ג. איינשטיין האיש הולך לאיבוד. חייו מתוארים רק בסגנון טלגרפי ויבש. ( )
  amoskovacs | Dec 3, 2011 |
One of the greatest geniuses of all time, who proposed the profoundly significant Theory of Relativity, believed in God! ( )
  ElTomaso | Jun 21, 2006 |
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A biography of Albert Einstein, told through various scientific and technical correspondences, including those with Michele Besso. Pais discusses the world of physics before Einstein, during Einstein's time and the impact on the scientific world after his death.

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"Sottile è il Signore, ma non malevolo". Con questa frase, Einstein commentava nel 1921 alcuni dati (poi rivelatisi errati) che avrebbero potuto mettere in crisi la sua teoria della relatività. Guidato da un marcato senso estetico, oltre che da una logica stringente, il pensiero einsteiniano si opponeva naturalmente a ogni complicazione non necessaria, sempre teso a ricercare la più semplice ed elegante delle spiegazioni al più complesso dei problemi. Dotato di una tenacia fuori dal comune, Einstein visse da solitario nella vita come nella scienza, spesso contro corrente, giungendo così ad alcune delle più eclatanti scoperte del XX secolo. Questa biografia, scritta da un suo allievo e amico, resta a tutt'oggi insostituibile e insuperata per chi voglia ripercorrere il cammino scientifico e umano del grande fisico.
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