Forgive my lack of clarity - the proposition is a hypothetical N3 violation during an otherwise perfectly elastic interaction, and repeated cyclically.
Suppose each mass is 1kg, and 1 Joule is input between them; normally they'd fly apart, each accelerated to 1 m/s in opposite directions. When the slack is taken up they bounce back together, and so continue oscillating indefinitely, with no net change in position or system momentum. If however one half of the interaction was reactionless - say, when the masses push off from one another, or else when the chord goes taut and they rebound, then the net system momentum, relative to a stationary observer, has increased. >From the internal reference frame aboard either mass, the net system is indeed conserved. Energy, too. But from an external frame, the net system has been accelerated. And if this anomally is repeated, the amount of increase in net system momentum each interaction remains constant - a linear rise in velocity as measured from the external frame. On-board, from the internal frame, the relative velocities between the two masses can remain a constant sinusoid - they never exceed a relative velocity of 2 m/s. It is immaterial, from their point of view, how that momentum is distributed between them as measured from some other frame. Internally, CoM and CoE always apply. But externally, we have a linear rise in system momentum - in this case, rising by a consistent .5 m/s per Joule (a 1 kg / m / s unbalanced momentum divided between two 1 kg masses gives a 1/2 m/s net acceleration). And whereas if we wanted to pay for such an acceleration by conventional means, the requisite input energy rises by half the square of velocity, here it remains a flat-line constant, independent of net system velocity. Again, the reason many folks forget that conservation depends upon N3 symmetry is that you have to repeat the outcome for the anomally to appear, since it is by its nature a differential and so emerges from how the energies evolve as they scale... Plus, such system invoke a third reference frame which must be considered before the anomally becomes apparent - an N3 violation in a 2-body problem is all but meaningless. On Mon, Feb 8, 2016 at 6:25 PM, Eric Walker <[email protected]> wrote: > Hi, > > On Mon, Feb 8, 2016 at 6:05 AM, Vibrator ! <[email protected]> wrote: > > So an effective N3 violation would allow you to create energy by >> effectively towing your reaction mass along for free. Consider two >> adjacent 1kg masses in free space connected via a perfectly elastic slack >> tether: an impulse is applied between them, but because abracadabra, only >> one moves, until they collide again; from either mass's frame of reference, >> that detail is irrelevant - if we input 1 J of energy then that's all the >> system has, and whether 1/2 a J resides in each mass or one has more than >> the other may seem academic... >> > > I followed your presentation, except for this part. It's not clear to me > how someone might propose that a system comprising two masses connected by > an elastic tether might be made to violate Newton's 3rd law. When the > first mass, which is initially set in motion, begins to accelerate the mass > that was left at rest initially once the tether becomes taut, its momentum > will decrease as the momentum of the second mass increases, conserving > momentum for the system as a whole. > > Eric > >
