Department of High Energy Physics

School of Natural Sciences

Tata Institute of Fundamental Research, Mumbai

     Precision measurements on Gravitation at Gauribidanur (Karnataka)

The Gravitation Experiments Group

The Primary Focus of our group is the Experimental Study of Gravity as a Fundamental Interaction. This primary interest naturally carries over to the experimental study of other posited feeble forces.

Central to our work is an instrument known as the Torsion Balance, and we pursue our experiments at a dedicated, low-noise underground laboratory at Gauribidanur in Karnataka. Though the torsion balance has a history going back more than 200 years, the fact is that modern torsion balances remain among the most sensitive mechanical transducers known. The questions we remain interested in are

  • Is the Principle of Equivalence violated at some really small level?
    (our design sensitivity is as small as a part in 1013)
  • Does the familiar Inverse Square law of Gravity break down at some length-scale?
    (our interest: violations at length scales below 1 millimetre, motivated by arguments from higher-dimensional theories)
  • Are there Fundamental Forces other than the 4 known ones?
    (our past work has imposed some of the best constraints worldwide on some flavours of these generic “Fifth Forces”)

  • At left, a schematic overlay depicting the Gauribidanur Laboratory, with a Torsion Balance in the Ultra-high-vacuum chamber at base, 80 feet underground;

    At right, a photograph of the lowest portion of the Equivalence Principle torsional suspension, with the composite mass-bob (Lead-Copper) and the mirror for angle-tracking

    We build our most sensitive instruments and control-systems ourselves (spanning the gamut over mechanical systems, optics and electronics) and are especially interested in young folk who like to do things with their hands.

    Associated Members


    Nadathur Krishnan
      Office LocationA 245
    Laboratory TIFR, Mumbai
    Research Interest

    Scientific Staff

    pereira@tifr.res.in22782538AB 84TIFR, Mumbai
    Mane Deepak B 22782538AB 84TIFR, Mumbai
    VAIDYANATHAN A Laboratory, Gauribidanur
    MALLIKARJUNA B S Laboratory, Gauribidanur
    SRINIVASAMURTHY P K Laboratory, Gauribidanur
    +91-9449044174Gravitation Laboratory, Gauribidanur
    +91-9449044174Gravitation Laboratory, Gauribidanur
    +91-9449044174Gravitation Laboratory, Gauribidanur

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