1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mach-Woodward Effect: New Experimental Measurement Setup Proposed

  1. Dec 15, 2012 #1
    Professor of Physics History at CalTech, Dr James Woodward has been investigating an idea called the Mach Effect, which is supposed to be based on Mach's Principle and which is claimed to allow a means for propellantless propulsion without violating Conservation of Momentum. The idea is that changing the internal energy of an object - electric charge distribution, for example - would cause its mass to change, and therefore oscillating this property in conjunction with mechanical oscillation could lead to an asymmetric acceleration force. Justification for non-violation of Conservation of Momentum is offered by way of Mach's Principle, claiming that the apparent change in momentum of the object is offset by an infinitesimal change in the momentum of rest of the universe.

    Woodward has been publishing results from his own experiments attempting to measure such an effect, however the results are so weak that they border on being inconclusive.

    A new paper has recently been published outlining a new experimental setup for more accurate measurement of any possible Mach Effect, postulating that use of magnetic fields in place of a mechanical oscillator should improve the means to observe and detect mass fluctuations, if any indeed occur:


    From p.78:
    Recognizing that the Mach Effect conjecture itself may not necessarily be valid, what are the opinions on this proposed improvement in the experimental setup and its claims of greater accuracy? Is magnetic field induced acceleration the best possible method to expose or discern whether or not mass fluctuations are occurring? If not, why not?
  2. jcsd
  3. Dec 15, 2012 #2


    User Avatar
    Science Advisor

    Changing the internal energy of an object requires either input or extraction of energy. Extraction of energy is a "propellant".
  4. Dec 15, 2012 #3
    Hi, thanks for your reply. Well, according to this conjecture, the asymmetric acceleration force which Woodward is trying to measure through his experimental apparatus is not being achieved by any expulsion of conventional propellant mass, nor is it even a photon rocket.

    The exact mechanism for momentum exchange is left unstated, however it's being claimed that momentum would be exchanged by the system with the rest of the universe.

    But as you say, momentum exchange cannot be done for free - it's just that it's being claimed that it can be done without expulsion of propellant mass.

    The cyclical oscillation of the change in internal energy means a corresponding cyclical oscillation of change in mass. This is then sychronized with mechanical displacement oscillation, which should result in an asymmetric net force to achieve acceleration.

    The new paper however claims that using an oscillating magnetic field instead of a mechanical oscillator could improve upon the measured results.

    Here are some graphs lining up various relevant parameters vs time:

    (Click to enlarge)

    You'll notice on the bottom 2 graphs the red curves which show the purported additional performance advantage of magnetic vs mechanical oscillation. The claim is that there is an increase in overall momentum transfer and acceleration. This claim is based on the different coupling that happens under a magnetic field as compared to direct mechanical contact. This should result in any mass fluctuations being more discernible and visible to measurement, with an improved signal-to-noise ratio.

    I'd like to know if there are any opinions on how the experimental setup could be further improved. Whether for the purpose of proof or disproof, it would be nice to know how the experimental apparatus could be optimized to make any mass fluctuations and any resultant net accelerative force as apparent as possible.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook