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

Eot-Wash sub-mm test inverse square law

  1. Jun 7, 2005 #1


    User Avatar
    Science Advisor
    Gold Member
    Dearly Missed

    Last year the Eot-Wash group found no deviation from invers sq. at close range (on order 100 micron)

    Sub-millimeter Tests of the Gravitational Inverse-square Law
    C.D. Hoyle, D.J. Kapner, B.R. Heckel, E.G. Adelberger, J.H. Gundlach, U. Schmidt, H.E. Swanson
    34 pages, 38 figures
    Phys.Rev. D70 (2004) 042004

    "Motivated by a variety of theories that predict new effects, we tested the gravitational 1/r^2 law at separations between 10.77 mm and 137 microns using two different 10-fold azimuthally symmetric torsion pendulums and rotating 10-fold symmetric attractors. Our work improves upon other experiments by up to a factor of about 100. We found no deviation from Newtonian physics at the 95% confidence level and interpret these results as constraints on"

    Now, according to Motl there is gossip that they think they did find some shortrange deviation from newton gravity inverse sq

    the Eot-Wash group is highly respected. here is a webpage on who they are
    with photographs
    http://www.npl.washington.edu/eotwash/people.html [Broken]

    Motl reports the gossip here

    the experimenters think (according to the rumor) that gravity at 100 micron distance is WEAKER than newton law says
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Jun 7, 2005 #2


    User Avatar
    Gold Member

    Thanks for the links. Both the finding itself, and the rumors that gravity may be weaker than expected at small scales is very interesting. Tests like the Eot-Washington group ones are long overdue. The cost of that apparatus has to be a tiny fraction of that of ventures like the large hadron collider, but equally fundamental.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook