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Coulombe drive?

  1. Nov 23, 2011 #1
    Brief description of problem: two independently-suspended platforms of equal mass are subjected to an intervening EM impulse, driving them apart.

    Upon the platforms are set a pair of solenoids to provide the impulse, and additionally a pair of pivoting magnetic armatures on one platform only, which mate with the solenoids on the opposite platform when at rest. The solenoids are angled diagonally so that the impulse is distributed evenly between x and y plan axes.

    When the arms are locked in place, the impulse drives the two equal masses an equal distance and speed - they move symmetrically as expected, clearly demonstrating Newton's third law.

    However when the arms are allowed to pivot some set angular distance, thus absorbing a portion of the impulse before transfering it to their platform upon reaching full lock, the platform is subsequently propelled a greater distance than its opposite - despite the net mass of both platforms remaining equal.

    An asymmetric exchange of inertial energies has apparently been demonstrated - the total displacement of the platforms in both the arms-free and arms-locked cases is equal, and equal to the input energy. Yet the asymmetric distribution of that energy has apparently caused a net momentum, from nowhere...


    Not sure if these are sims but also have some test rig vids; a rail test, pendulum test and apparently its also passed float tests (tho no video). It's patented as a ship propulsion system.

    Stiction is clearly an unsatisfactory explanation in this case, so anyone, please elucidate..??.

    NB. Should just clarify - the system can be configured to gain momentum, or just position, depending on how elastic the connection is between the two platforms - in these anims and the rail test, it gains position. In the float or pendulum tests it gains KE.
    Last edited: Nov 24, 2011
  2. jcsd
  3. Nov 24, 2011 #2
    Not no one eh? Not even with a barge pole?

    Bah, talk about lead balloons...
  4. Nov 24, 2011 #3
    There have been more posts like this.

    Lots depends on which kind of track surface your platforms are rolling on. One way or the other some momentum will be transported to the track the platforms are rolling on.
    The platform with the higher initial velocity will experience the higher friction, therefore imparts a higher momentum to the track, and therefore doesn’t roll as far.

    Before you decide to buy shares in that boat company first look at these:
    www.colorado.edu/physics/2000/microwaves/water_rotates4.html [Broken]


    rolling friction - Web Physics Project
    Last edited by a moderator: May 5, 2017
  5. Nov 24, 2011 #4
    Thanks for taking a look but i wouldn't be here asking about a stiction drive - there's video of pendulum (actually parallelogram) demonstrations, and the two anims linked above i think might be a Newtonian sim - but i only found these on YT last night and don't know their provenance - if however they're physical then again, there's no contact surfaces involved.

    I further recognise that static friction isn't the last word and that, for example, float tests can provide a false positive. However in this case there doesn't appear to be any vertical component to the mechanical actions that might vertically translate the center of mass so as to vary the drag or whatever..

    I'll have to upload some vids of the parallelogram tests, but in the meantime i'm particularly intrigued by the prospect of those anims being Newtonian sims... does anyone recognise the software package used..?

    Edit: This video is particularly compelling - especially the high speed camera section where we see a clear effect relative to the control case...

    Last edited by a moderator: May 5, 2017
  6. Nov 24, 2011 #5
    And two more:



    Each of the three tests (rail, pendulum and float) seems to eliminate potential weaknesses in the others. The only test we lack video for is the float test, but again, if those anims are Newtonian then that more than makes up for it - and besides it's patented as a marine propulsion system so i'm willing to give it the benefit of the doubt that the float test exhibits this same behaviour.

    Other trivia:

    Apparently the diagonal vectors are critical

    It is also claimed that the system depends on a minimum of two modules as shown - the r/h/s carriage cannot propel itself by wagging its flippers, as some have opined.. rather the effect is specifically an asymmetric distribution of KE from an intervening impulse between two loosely connected equal net masses.

    I have as yet been unable to ascertain whether magnetism is a critical factor - could the impulses be purely mechanical, or, say, small explosive charges, gas guns etc? Are solenoids just a convenient source of impulse, or is the apparent asymmetry dependent on properties of magnetism?

    Edit: the most obvious explanation seems to be that when the arms flip, the platform they're fixed to can't fully reciprocate in the opposite direction by dint of being attached to rails / water / hanging from wires... also, it's obstructed in its leftwards progress by the left side platform being in its way, which is also attached to rails / wires or whatever. It's pushing against the Earth rather than itself.

    But then why would diagonal vectors be required? They shouldn't make any difference. And a Newtonian sim of it should just wobble in free space. That the armature's counter-motion is somehow damped is self-evident, but how exactly - is this KE sunk through the apparatus to earth, or somehow cancelled out? That's the crucial question..
    Last edited: Nov 24, 2011
  7. Nov 24, 2011 #6
  8. Nov 25, 2011 #7
  9. Nov 25, 2011 #8
    Well, i've now received confirmation that magnetism isn't crucial to the claim.

    However i'm still stuck on the claimed requirement for two modules - if it's just a stiction drive then the left hand module seems entirely redundant... unless it just further damps the counter-inertia...

    Likewise, the angular displacement of the arms is said to be critical, yet if it's just a stiction drive then a simple 90° rotation from X to Y should suffice.. again though, this further conflicts with the claimed necessity for diagonal vectors...

    Can anyone see a way to interpret the claims consistently with it being a stiction drive..? Ie. what was the inventor thinking (right or wrong - i still don't see his train of logic that led to this configuration)..?
  10. Nov 25, 2011 #9

    D H

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    The "proof by youtube" mechanism of proving a conjecture is about as lousy a mechanism as one can get.

    Thread locked pending moderation.
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