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Science

How Einstein Lost His Bearings, and With Them, General Relativity (quantamagazine.org) 119

Kevin Hartnett, writing for Quanta magazine: Albert Einstein released his general theory of relativity at the end of 1915. He should have finished it two years earlier. When scholars look at his notebooks from the period, they see the completed equations, minus just a detail or two. "That really should have been the final theory," said John Norton, an Einstein expert and a historian of science at the University of Pittsburgh. But Einstein made a critical last-second error that set him on an odyssey of doubt and discovery -- one that nearly cost him his greatest scientific achievement. The consequences of his decision continue to reverberate in math and physics today.

Here's the error. General relativity was meant to supplant Newtonian gravity. This meant it had to explain all the same physical phenomena Newton's equations could, plus other phenomena that Newton's equations couldn't. Yet in mid-1913, Einstein convinced himself, incorrectly, that his new theory couldn't account for scenarios where the force of gravity was weak -- scenarios that Newtonian gravity handled well. "In retrospect, this is just a bizarre mistake," said Norton. To correct this perceived flaw, Einstein thought he had to abandon what had been one of the central features of his emerging theory. Einstein's field equations -- the equations of general relativity -- describe how the shape of space-time evolves in response to the presence of matter and energy. To describe that evolution, you need to impose on space-time a coordinate system -- like lines of latitude and longitude -- that tells you which points are where.
Another interesting read on Quanta: Why Stephen Hawking's Black Hole Puzzle Keeps Puzzling.
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How Einstein Lost His Bearings, and With Them, General Relativity

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  • by Anonymous Coward on Monday March 19, 2018 @08:12AM (#56282819)
    In this era of computers and CPU's and constant distraction, he wouldn't have managed to get to even first realization. The Theory of Relativity was a triumph of abstract thought; this is something that doesn't really happen anymore.
    • by Anonymous Coward

      Abstract thinking does still occur, just that modern computing smacks em down real quick as being invalid.

    • This is a good point of discussion. Things aren't as black and white as you imply, of course, but distractions are way up these days.

      I came up with my theory [just-think-it.com] because of an unusual job situation -- caring for first one and later a second Alzheimer's person, on very long shifts, the second one at night -- one in the country, the second where I wasn't able to have the lights on.

      I listened to a physics series on audio player almost every waking minute for a year and a half.

      So it can be done, but circumstances

      • Really interesting! Later, today, I will take time to read it thoroughly. Thanks for posting about this.
      • by DrJimbo ( 594231 )

        I looked at some of the pages on your site trying to find an example of an actual prediction of spring-and-loop theory, not just a bunch of hand waving. For a theory that you claim solves so very many problems while the existing theories are trash, it shouldn't be so hard to come up with one explanation.

        So please, point me to an example of how to use SAL to make a numerical prediction. Since you claim to have a better replace for pretty much all of the existing mainstream physics theories there shou

        • It is not the first step of a theory but a last step to provide specific numerical results. What has been accomplished so far is not too shabby, considering it has been done with zero budget. Please compare $0.00 with the $5,000,000,000/year waste that is the LHC.

          Also note that many of the predictions made by Spring-And-Loop Theory do not need to be numeric to be significant. That is the whole point of a new model. You are like a buggy whip maker demanding I show you a new and improved buggy whip.

          For ex

          • by DrJimbo ( 594231 )

            Views like yours are the real problem -- bought and paid for "scientists" with zero incentive to support anything that actually works.

            Bullshit. I am not bought and paid for. I never was. All you seem to do is insult those around you without providing any evidence at all that your theory has any value.

            My view is I want to support you but you need to provide me with some evidence that your theory has value. If you want to replace the standard model and general relativity and so much more, that's fine but extraordinary claims require extraordinary evidence. But I'm not asking for extraordinary evidence, I'm asking for a shred of evid

    • Re: (Score:1, Funny)

      by Anonymous Coward

      What the hell are you talking abou

    • Re: (Score:3, Interesting)

      by Anonymous Coward
      "Abstract thought" still occurs. It's just that you best keep your mouth shut or wind up being labeled a crackpot.
    • by Roger W Moore ( 538166 ) on Monday March 19, 2018 @12:08PM (#56283915) Journal

      In this era of computers and CPU's and constant distraction, he wouldn't have managed to get to even first realization.

      ....and yet there are thousands of papers published by theorists each year which suggest that people still manage to come up with abstract new ideas in fundamental physics for us to test in our experiments. While it is true that none of these have been as significant as Einstein's papers that's not surprising: if papers this significant came up on a regular basis it would mean that we were doing a really bad job figuring out how the universe works. There were 200 years between Newton and Einstein and another hundred years later we are still only just seeing some of Einstein's predictions for the first time with gravitational waves being the latest discovery.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      If Einstein didn't come up with it, someone else would have in the next 5 years. He wasn't working in a vacuum. The idea that matter and energy are interchangeable some way was already well on it's way by Poincaré and others before Einstein. Lorentz already described time dilation and the Lorentz transformations is pretty much the basis of special relativity.

      Look at Hawking and the state of the art now in theoretical physics. You have many people that are/were probably on the same level as Einstein was

      • by slew ( 2918 )

        If Einstein didn't come up with it, someone else would have in the next 5 years. He wasn't working in a vacuum.

        Actually there is considerable evidence that Hilbert was basically working on general relativity at the same time as Einstein and submitted an article for publication 5 *days* before Einstein's publication (although Hilbert needed to work out a few changes with the publisher in his result and his formulation wasn't published until 3 months later). There is an on-going dispute on who actually got the math right first for the correct field equations, although most agree that the foundational ideas/inspiratio

        • Actually there is considerable evidence that Hilbert was basically working on general relativity at the same time as Einstein and submitted an article for publication 5 *days* before Einstein's publication (although Hilbert needed to work out a few changes with the publisher in his result and his formulation wasn't published until 3 months later). There is an on-going dispute on who actually got the math right first for the correct field equations, although most agree that the foundational ideas/inspiration about Relativity were from Einstein...

          That dispute was not started by Hilbert. Despite his concurrent work, Hilbert credited Einstein with the discovery of General Relativity. [wikipedia.org]

      • by GuB-42 ( 2483988 )

        In fact I believe that what drive theoretical physics is not the genius of a few scientists but precision and observation.
        A few centuries ago, there is no way we could have observed the effects of relativity, measurements weren't precise enough, and we had too many unknowns. If Newtonian physics give the right answer within the margins of error of the time, then there is no reason for another, more complex theory to exist.
        In order for science to advance, we first need data to disprove the theory of the time

    • This is why I've been contemplating switching to a feature phone and having only 1 personal computer. Maybe even get rid of a phone altogether. The problem is the rest of the world operates in the internet/smartphone paradigm, so I would be handicapping myself. But the distractions abound and continue to grow. There is no respite. Since we are all addicted to our devices, we are all equal slaves, so it doesn't really improve our lives since we are all "advancing" at the same rate.
  • by Anonymous Coward

    What actually happens when matter turns to energy and back?
    What's the difference between energy that is electromagnetic and energy that is motion?
    Why the difference?
    Can you turn motion energy into photon energy?
    Why not?
    Where does the value of C come from?
    Why is there a limit at all?
    Why is that limit exceeded by observation?
    How come there are so many forces?
    Why is gravity only an attraction force and others not?
    What is time?
    Why does inertia and momentum require time?
    Why don't things happen instantaneuosly?
    Wh

    • Re: Questions (Score:2, Informative)

      by guruevi ( 827432 )

      Read Einstein's books, they aren't copyrighted anymore and have all those answers.

    • Re:Questions (Score:5, Insightful)

      by Anonymous Coward on Monday March 19, 2018 @10:35AM (#56283377)

      What actually happens when matter turns to energy and back?

      It has never been observed to completion, only buildup of mass on high-speed particles and significant energy release on disassembly of atoms.

      What's the difference between energy that is electromagnetic and energy that is motion?

      How it interacts with other energies.

      Why the difference?

      They are essentially different, but also somewhat similar. That's why you are having trouble disconnecting the similarity in names from the difference in meaning.

      Can you turn motion energy into photon energy?

      There are many means of conversion.

      Why not?

      False.

      Where does the value of C come from?

      Observation and calculation.

      Why is there a limit at all?

      We suspect there is a limit because Maxwell's Equations have an asymptote at that value. We accept that there is a limit because high energy testing shows the predicted behavior.

      Why is that limit exceeded by observation?

      It hasn't been.

      How come there are so many forces?

      There are 4.

      Why is gravity only an attraction force and others not?

      Gravity and the strong nuclear force are attraction, the weak nuclear force is repulsion. Magnetism is directionally attraction.

      What is time?

      A direction.

      Why does inertia and momentum require time?

      By definition.

      Why don't things happen instantaneuosly?

      Things do, and trends don't.

      What if they do? How would we perceive that?

      You wouldn't. At best, your perception is functional on the order of 10^42 hypothetical distinct moments per AC observation.

      What would motion look like in a world where everything happens instantaneously?

      Have you been to a rave with a strobe light? Start from there.

      • by Quirkz ( 1206400 )

        Bravo! And from an AC, no less.

        • Ditto. And the fun bit at the end when the AC got a little snarky...

          "
          Why don't things happen instantaneuosly? [sic]
          Things do, and trends don't.

          What if they do? How would we perceive that?
          You wouldn't. At best, your perception is functional on the order of 10^42 hypothetical distinct moments per AC observation.
          "

      • by slew ( 2918 )

        Mass and energy are basically the same thing when it comes to inertia/acceleration/gravity. You measure "mass-energy" and the quantity is conserved (mass doesn't disappear, it converts to energy, and vice-versa). What most folks think of as "build-up" of mass at high velocity is really just a build up in momentum/energy (mass and energy are the same and you can store energy in momentum, what people think of as E=mc^2 is more properly E^2 = (mc^2)^2 + (pc)^2 + other energy terms, where p=momentum) and it

    • Can you turn motion energy into photon energy?

      Can you plug a fucking lightbulb into a generator? No; can you?? Apparently, that's up for debate...

    • Why is that limit exceeded by observation?

      What?

      Why is gravity only an attraction force and others not?

      Because it's not a force.

    • There's a whole slew of videos explaining this stuff on youtube now, like these two (also look at Don Kennedy and Nick Lucid). I particularly like the photon box as an explanation of inertial mass.

      https://www.youtube.com/watch?v=gSKzgpt4HBU [youtube.com]

      and

      https://www.youtube.com/watch?v=fHRqibyNMpw [youtube.com]

  • by Njorthbiatr ( 3776975 ) on Monday March 19, 2018 @08:30AM (#56282877)

    Gravity exists in the real word, independent of any coordinate system and it behaves consistently. There's no reason why it shouldn't be able to be described as such; we just don't know what that description is.

    Saying that "oh noez Einstein ur on a wild goose chase!" is pretty darn silly.

    • by fermion ( 181285 )
      Gravity tends to create it's own reference frame which can then be used to construct a coordinate system that can then be used to model the data analytically. All natural phenomena is independent of human constructed coordinate systems. It is true that classical physics is dependent on the reference frame, at least to some extent, but that is one of the many assumptions made.
      • Gravity tends to create it's own reference frame which can then be used to construct a coordinate system that can then be used to model the data analytically. All natural phenomena is independent of human constructed coordinate systems. It is true that classical physics is dependent on the reference frame, at least to some extent, but that is one of the many assumptions made.

        Newtonian physics is also relative, how much changes between different frames of reference is just a lot less than in general reletivity.

      • That's why Lorentz invented invariance [wikipedia.org]
        • Lorentz only considered inertial frames.

          • You just use a scalar to render any coordinate system choice or velocity differences irrelevant. For example, earths orbit around the sun is not affected by the orbit of the solar system around the galactic center, nor the galactic center traveling through space . If it was coordinate system dependent then physics would be a very different animal indeed.
      • Re:He's not wrong. (Score:5, Interesting)

        by tinkerton ( 199273 ) on Monday March 19, 2018 @10:36AM (#56283389)

        Classical physics does not depend on a reference frame as long as the limitspeed is infinite and until 1880 or so that was the assumption. I mean it was known that the lightspeed was finite but there was no reason to believe it was the limitspeed. You can turn newtonian mechanics into a covariant system for general coordinate systems but why would you do that? If you want to describe a merry go round , don't get all that overhead and use a shortcut.
        Then with special relativity you could again decide to do the same: support general coordinate systems, make it work for accelerated observers. You could still classify it as special relativity.

        It was Einstein who decided we couldn't avoid to formulate things in a covariant manner, and the example was that inside an elevator it was strictly impossible to distinguish between floating in space or plummetting towards the earth in free fall and and likewise there was no distinction between standing on the surface of the earth and being pulled in space.
        Therefore the math had to be the same too.

  • Was it a mistake? (Score:5, Insightful)

    by tomhath ( 637240 ) on Monday March 19, 2018 @09:53AM (#56283161)

    the monumental effort to reconcile general relativity with quantum theory flounders in part because of the difficulty of developing a theory of quantum gravity that has the same general covariance Einstein achieved with his field equations. “In some sense you could argue the reason we don’t have an adequate quantum theory of gravity is we don’t know how to express the solutions to Einstein’s equations in a way that completely removes any kind of coordinate dependence,” said Weatherall.

    It sounds like he recognized that there was something he couldn't explain, so he backed off a bit and looked for the explanation rather than charge forward and risk looking foolish.

    • I'm with you on this. It's not like he could just check Wikipedia (or even conduct an experiment on his own) to be sure.
    • by shoor ( 33382 )

      Einstein apparently consulted some 'pure' mathematicians for help with some of this. From the wikipedia article on David Hilbert:

      By early summer 1915, Hilbert's interest in physics had focused on general relativity, and he invited Einstein to GÃttingen to deliver a week of lectures on the subject.... Einstein learned that Hilbert was also working on the field equations and redoubled his own efforts. During November 1915 Einstein published several papers culminating in "The Field Equations of Gravitati

  • "lost his bearings" and "greatest physicist of all time"

    Don't do either of these, whoever writes about it.

    • "lost his bearings" and "greatest physicist of all time"

      Don't do either of these, whoever writes about it.

      Why not? Maxwell arguably was one of the "greatests physicist of all time" and was quite lost and off the rails when he argued that it would be impossible for heavier than air objects like humans to ever fly.

      • I didn't know Maxwell ever said that but I know he was pretty damn smart and he knew about the montgolfiere, about catapults and about primitive rockets, so I'm thinking his quotes about flying will have been a bit more subtle than 'it's impossible for heavy things to fly'. There were no lightweight engines at the time that's for sure so technically it was not yet possible.

      • Because it is disrespectful.

  • That even on their best day bright, intelligent people can have a bad day? Maybe he didn't get laid or maybe he did and thought of a different angle. You'll never know the exact answer unless you were there so stop speculating.

  • by Anonymous Coward

    Einstein did not "lose" general relativity, he just delayed publishing because he had doubts and was investigating them. The summary even says so on first paragraph.

  • by CaptainDork ( 3678879 ) on Monday March 19, 2018 @10:23AM (#56283305)

    ... back.

    WTF is this?

    Hawking passes and we get Slashdot Esquire magazine?

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