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Testing Equivalence Principle: Prying Gravity From Inertia

  1. Feb 15, 2013 #1

    So I came across this article on the internet, and it was about the Equivalence Principle. So I were interested and read it all, and in the article it said that the EP might be only approximately true. What interested me more about the article was it said that any theory of quantum gravity must violate the equivalence principle at some level. Before reading this article I always thought that the EP was established physics, I mean I thought it was experimentally proven...

    I'm just a layman who is greatly interested in development in theoretical physics, so I'd be grateful if you could try to reply in less technical terms. Also forgive me for my poor English, I tried to do my best :)

    Here's the link to the articles I read:
    1. http://www.forbes.com/sites/johnfar...s-seek-a-divorce-prying-gravity-from-inertia/
    2. http://www.wildcat.arizona.edu/arti...lenges-einsteins-theory-of-general-relativity
  2. jcsd
  3. Feb 15, 2013 #2


    Staff: Mentor

    The equivalence of inertial and gravitational mass has been experimentally verified to 1 part in 100 billion:


    (See under "Related Studies", the experiment run by Roll, Krotkov, and Dicke.)

    Unfortunately, neither of these articles links to an actual scientific paper, so it's hard to say much that's useful. Pop science articles are not good sources if you actually want to understand the science.
  4. Feb 15, 2013 #3
    Thank you so much for your reply and enlightening me up on the topic :) I searched for the paper by the professor at the university and I found this, I'm not sure if its what a scientific paper per se, but it does have maths so I thought you might want to take a look. I'm sorry if its just nonsense, I'm really sorry.

    http://ptep-online.com/index_files/2012/PP-31-08.PDF [Broken]
    Last edited by a moderator: May 6, 2017
  5. Feb 15, 2013 #4


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    I note that none of the 3 arxiv entries on this topic by Lebed are published in peer reviewed journals; none are cited by anyone else. It is conceivable that something will come of this, but it is premature to grant any significance to it. Of note is that many papers of Lebed on condensed matter physics are published in major journals, but not any of these papers challenging the EP. (Note: "Progress in Physics" is not listed as a citable journal in Thomson Reuters).
    Last edited: Feb 15, 2013
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