Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help me in mach's principle

  1. May 5, 2004 #1
    plz,any one could help in in illustrating the mach's principle.I want to know on what basis he has arrived at the conclusion.some best articles that u suggest to gothrough...
    does einstein's theory include the principle or not?i think it has got the place in gr.
  2. jcsd
  3. May 5, 2004 #2
    Einstein vs. Bohr by Dr. Mendel Sachs
    The Science of Mechanics by Ernst Mach

    2.4 "Mach's Principle"
    To be sure, for a number of years Einstein expressed the ambition of the general theory of relativity to fully implement Mach's program for the relativization of all inertial effects, even appending the so-called "cosmological constant" to his field equations (1917b) for this purpose. This real point of contact of Mach's influence was clearly identified only in 1918, when Einstein distinguished what he baptized as "Mach's Principle" (roughly, that inertial effects stem from an interaction of bodies) from the principle of general relativity which he now interpreted as the principle of general covariance. Taken together with the principle of the equivalence, Einstein asserted that the three principles, were three "points of view" on which his theory rested, even if they could not be thought completely independent of one another. Despite Einstein's intent, there is considerable disagreement about the extent to which, if at all, general relativity conforms to "Mach's Principle". In part this is due to vagaries regarding what the Principle actually asserts and then again, to difficulties in comprehending what physical mechanism might implement the Principle, however interpreted. How, for instance, could a body's inertial mass be accounted due to the influence of all other bodies in the universe? (See the discussions in Barbour and Pfister (1995)).
    SOURCE: http//plato.stanford.edu/entries/genrel-early/URCE:

  4. May 6, 2004 #3
    Mach's conjecture is still an open problem,it was not disproved yet.However,in spite of Einstein's intentions,nowadays physicists do not consider it (Mach's principle) as crucial for General Relativity;indeed DeSitter found solutions of Einstein's equations characterising expanding universes even in the total absence of matter.Thus it is accepted the minimum interpretation,the principle of equivalence could represent only a partial integration of Mach's principle into GR.This interpretation is evident even in the usual approaches of classical problems,for example if we were to accept Mach's principle (as Mach put it) then we should treat centrifugal forces as being real forces or in all mainstream treatises it is specifically underlined the fact that they are imaginary.
    Last edited: May 6, 2004
  5. May 6, 2004 #4
    Mach thought that the inertia of a local mass was caused by all the other masses
    in the universe.If there are a finite number of Higgs particles in the universe to cause mass, isn't this true? If I could remove a galaxy from the universe then the higgs particles associated with its atoms would be redistributed among the remaining atoms of the universe and they would presumably all have a slightly higher mass than before.
  6. May 6, 2004 #5


    User Avatar

    I recall reading Einstein said that Mach's principle in its' original form had been very helpfull in early days of GR development.During the years he admited he changed his mind about interpretation of the principle (ie the meaning of it).
    Still open problem,I agree.
  7. May 6, 2004 #6


    User Avatar
    Homework Helper

    The principle was to address the problem of centrifugal force, which had managed to preserve some vestige of the notion of absolute space which remains inescapable in most classical mechanical treatements that are not specifically taylored to eliminate it.

    You can look into some of the writings of Bishop Berkeley for a related perspective.

    You can find a treatement of Mach's principle in the translated work of Einstein, The Meaning of Relativity. The weak, low velocity approximation is used. A material particle is indirectly demonstrated to experience a centrifugal and coriolis force by virtue of the motion of the source body.
  8. May 7, 2004 #7


    User Avatar

    Would you be kind and be more specific regarding Bishop Berkeley's writings you are reffering to?I didn't read it.Publisher,title?

  9. May 7, 2004 #8


    User Avatar
    Homework Helper

    This is gonna sound terribly uncongenial, but no. I remember reading some stuff in passing, but I didn't write it down, and I don't have time to go track it down. I did a quick search on the web just before I posted that last post of mine in order to see if I could pin down a specific citation or source, but to no avail. You can consider the name as a tenuous lead, and follow it if you are truly interested.

    Just so we're clear and you don't get surprised though, Mr. Berkeley was a straight-up philosopher, not a physicist. It wasn't so much what he said; it was the clarity with which he exposed a long-time concern of mine that I could never seem capable of communicating. Frankly, he may be quite bogus, but I happen to agree with the little that I have read.
  10. May 10, 2004 #9
    Consider going to Amazon and doing a search on Julian Barbour. I have a copy of his _Mach's Principle: From Newton's Bucket to Quantum Gravity (Einstein Studies, Vol 6)_
    which is out of print but might be availalbe at university libraries, and have pre-ordered _Absolute or Relative Motion: The Deep Structure of General Relativity_ which he has been promising for years now... He alludes to some of the ideas he will present in his _The End of Time: The Next Revolution in Physics_ and claims a deep connection between GR and Mach's principle beyond what even Einstein held, then backed away from.

    (I on the other hand do not think Mach's principle is correct, and inertia can be explained as a local phenomina related to mass. But this is purely a personal view, and a side issue of my own research.)
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Help me in mach's principle
  1. Mach's principle (Replies: 58)

  2. Mach's principle (Replies: 7)

  3. Mach's principle (Replies: 42)

  4. Mach principle (Replies: 3)

  5. Mach's principle (Replies: 1)