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Newton Vs Einstein

  1. Jul 16, 2010 #1
    What was the conflict between Newton and Einstein? what they division Classical and Modern Physics after after theory of relativity?
  2. jcsd
  3. Jul 16, 2010 #2
    Yeah! Get your vuvuzela’s out and blow them for your favourite. Who do you support? Newton or Einstein?

    Actually, abrowaqas, there is no conflict. It would be a bit difficult for Newton to be in dispute with Einstein, because he lived three hundred years earlier. And in point of fact, Einstein paid glowing tribute to Newton.

    Newton formulated some laws of motion that seemed to explain the reality we observe around us. For two hundred years and more, they seemed to fit the bill. Then, as science started to push the boundarys a little harder, one or two cracks appeared. So Einstein offered a new explanation, one that didn’t just show where Newton was not quite right, but showed why Newton had appeared to be right under the circumstances we had thus far encountered.

    Doubtless, at some time in the future, physics will be able to show where Einstein’s explanation wasn’t quite the complete one either. That doesn’t mean that there will be any conflict with, or loss of respect for Einstein.
  4. Jul 16, 2010 #3


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    I see it like this:

    The theory of Newton explained a lot of things surrounding us, and it has a certain symmetry group: the Galilei group. Nowadays physicists think symmetries are extremely important, but back then this wasn't realized in such a way.

    But then the theory of electromagnetism was found by Maxwell and others. It turned out to be a sound theory in every scientific perspective, but the problem was that it was imcompatible with Newton's symmetrygroup (the Galilei group).

    So, the question was: what would have to be adjusted to solve this conundrum? Maxwell or Newton? It turned out that Newton was approximately right; it's an approximation of a theory which is now known as the theory of relativity.
  5. Jul 16, 2010 #4
    There is really no such thing as a conflict between those theories. General relativity is simply an improvement over Newtonian physics.

    There are two main differences which lead to different results in case the gravitational field is very strong or velocities are very high.

    • Unlike in Newtonian theory gravity does not act immediately but acts with the speed of light.
    • In General Relativity the gravitational potential is effected by relativistic effects.
    Last edited: Jul 16, 2010
  6. Jul 16, 2010 #5
    IMO The fundamental conflict between the two perspectives is that Newton's essentially viewed physics [at that time this meant mainly mechanics and kinematics] in absolute terms, while Einstein's perspective was in that respect self evidently completely relative.

    Newton wanted to place the Gallilean coordinate space in an absolute frame.
    Einstein defined a coordinate space that was wholely relative.

    It should be noted that despite Newton's philosophical and logical desire to find a basis for an absolute space, an actual rest inertial frame to refer to, in the end he was per force a complete relativitist.

    Not surprising given that he was no fool and that is the empirical reality we live in.

    BTW I "absolutely" agree with Ken Natton in that it is irrelevant ,,if like Newtons mechanics and gravity, SR and GR are eventually found to be limited or even conceptually outright wrong , they will always remain among the most amazing and profound leaps of human intelligence and conseptualization.
    Aside from that; they totally changed not only what we thank about the nature of the universe, but in a real sense how we are able to think about that universe. In this way they influenced not only all of us that followed but also the physicists of the time.

    To a certain extent this conflict remains today. As far as I know Einstein himself at various points considered that motion might be both real and relative but it appears that a majority of those in the field today reject even the possibility, while others ,like Newton ,continue to believe there might be an absolute physics and frame that we just cant see or have not yet discovered.
    Last edited: Jul 16, 2010
  7. Jul 16, 2010 #6
  8. Jul 16, 2010 #7

    George Jones

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    What is "gravitational potential"? In general, does such a thing exist in general relativity?
  9. Jul 16, 2010 #8
    Good point, I just tried to keep it simple.

    The Weyl form is just about the closest to a gravitational potential I can think of but those solutions of course only apply to the simplest spacetimes.
  10. Jul 16, 2010 #9
    Hi I couldnt go through all posts but this is what I feel Real Newton vs Einstein,
    Newton in his theory of gravitation said that gravitation occurs 'instantaneously', let us suppose that somehow our sun has reduced its mass to half of of its original mass... So when does earth experiences this change in gravitational force? According to Newton it should experience instantaneously i.e, as soon as sun reduces its mass, but we know even light takes around 8 minutes to travel from sun to earth... This implies that gravitational waves or gravitons should propagate with speed more than 'speed of light'...Which is inconsistent with one of the postulates of 'special theory of relativity', i.e, Speed of light is maximum attainable speed by any particle. Therefore Einstein formulated 'General theory of relativity' to solve this inconsistency between 'special theory of relativity' and Newton's theory of gravitation.....
  11. Jul 16, 2010 #10
    Historically, the disagreement between Newton and the relationists is fascinating - but as far as I know Newton was never a relativist, so I'd be very interested in more information or links about this, and the sense in which you understand him to be or heard him described a relativist.

    Newton believed in absolute space largely because he believed in absolute acceleration, as witnessed by the behaviour of spinning buckets. Absolute acceleration is a real challenge to explain if you're a relationist; even in Special Relativity, acceleration is not relative but absolute and it's not at all clear SR embodies a thorough relationism. What is true is that, for Newton, it was never possible to find out an object's absolute velocity - but since he couldn't make sense of absolute acceleration in terms of changes of relative velocity he thought he had to accept it.

    Interestingly, if you formalise Newtonian Mechanics in a 4-dimensional manifold, and give the manifold enough structure to support the notion of an inertial path through space-time, you can get a Newtonian mechanics which supports absolute acceleration without absolute velocity and absolute rest, and so eliminate the embarrassing feature that so enraged relationists. Alternatively, work of Barbour suggests that, if you restrict your attention to solutions of Newtonian equations which have zero sum angular momentum (so avoiding embarrassing rotating buckets) you can formulate the theory without appealing to any primitive inertial structure of space-time, or anything involving absolute velocity.
  12. Jul 16, 2010 #11
    Hi As stated , he was only per force ,,[through lack of option] a relativitist.

    As you mentioned he was unable to find an objects absolute velocity.

    SO the inertial frame remained totally relative (Gallilean) construct and he couldn't find a conceptually valid base to do otherwise.

    The first postulate didn't arise from theoretical considerations but was directly founded on the apparently inescapable constraints of empirical reality , no??

    SO you could say that this only represents my own logical inference from the foregoing

    Not that I was impllying that he thought of himself or called himself a relationist.

    Is that the term of the times? I seem to remember the term associated with Mach.????

    As for sources; my memory is a sieve for that kind of factual info. I remember reading ,years ago. about his spiritual and philisophical side and how this effected his theoretical views and belief in an absolute frame .
    Last edited: Jul 16, 2010
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