WaltzCee wrote:- A weight can't go up for free, but the solution of time (or averaged imbalance) is still an option to consider: time-variant force...
I'm working on a simulation. It's a 6 foot radius with 400 pounds evenly distributed. I noticed when I double velocity of the motor there's 4 times the rotational energy on the wheel. IOW, the motor needs 4 times the energy to double velocity. Moving things faster is expensive. Can gravity pay that mortgage?
My thinking was
"gravity isn't a conservative force". Not in the sense it was like other non-conservative forces, ie friction, but
in the sense one could find more energy coming down than needed to go back up.
Any vector analysis of that idea to date proves, yes, up = down in the best of circumstances. Often times masses can fall and dissipate energy such that they can't even return to where they came from when there's no frictional losses of any sort (in simulation). But for the sake of argument, give the point gravity isn't conservative as I outlined. OK, where did that energy come from? Conventional physics would be looking for motors and batteries.
- The only way a gravity powered wheel is possible is if there is some injection of energy, either by fraud (with a motor and batteries or changes in atmospheric pressure or some thermal gradient or . . .) or by the creation of energy.
This is where my thinking has evolved. An honest working wheel is going to create energy. I don't see it happening any other way.
Exactly. 'Edge speed' of a wheel for a constant RPM squares with radius, hence so does angular inertia - and because rotational KE is 1/2 MoI times RPM squared, doubling velocity quadruples the RKE, and halving it quarters it.
The difficulty of getting gravity to pay anything is this fact that neither it, nor mass, change in time - they're static fields, and a closed-loop trajectory through a static field (or any combination of them) should have zero net energy, since energy is force times displacement, and if the latter's a closed-loop then no matter the path, if the former's static in time then we must've travelled equal distance up vs down the fields' force gradients (or inwards vs outwards, higher / lower field densities, uphill / down hill etc.).
An over or under-unity system is thermodynamically open, not closed, and can only arise when the forces in question are time-variant - so,
not static unchanging forces...
This means that the key variables in an OU interaction are going to be ones that are a function of time - such as speed - and this time-dependent factor has to be different between the input and output strokes of the complete interaction cycle.
That's about as fundamentally general a description of the exploit we can be sure of - conservation of energy and momentum depend upon the fact that fields like mass and gravity don't change in time, and their forces are mediated instantaneously at lightspeed.
But this is also the reason why MoI is likely our key wildcard. Linear inertia is invariant due to mass constancy, but angular inertia is a function of mass times radius squared.. so it
can change in time.
And when MoI halves, conservation of angular momentum applies and doubles velocity to compensate the drop in MoI, keeping net momentum constant... whereas RKE = 1/2MoI*RPM^2, so doubling the velocity while halving the MoI doubles the RKE. Again, this is another example of how different scaling dimensions are affected differently by these time-variant factors - while MoI and RPM are locked into a linear covariance, the relationship between RPM and RKE has the additional time derivative of frequency-squared. But that's just the distinction between momentum and energy. What we need is a system in which input vs output energies have different scaling dimensions - one being a function of time, the other merely of displacement, or else some kind of differential where rates of change of energy or an energy component is variable between I/O strokes.
Of course most if not all forms of motor or actuator can be thought of in these same terms - the difference being that normally, we pay for the field and force variations, whereas what we need is a passive variation - something that happens by itself, without cost to us.
I suspect that the "game" referred to in the writing on the toys page refers to the accompanying upturned whistling top - that of trying to get one to spin upside down, which is impossible due to its predilection for raising, rather than lowering, its MoI - as most rotating system are wont to do.
All my attempts to actually generate energy mathematically tend to come back to this same requirement, for passively self-reducing MoI.
Bessler wasn't using opposing balanced masses like i've shown above - his weights alternated inner / outer positions, so are in their high-MoI state when fully swapped around, and their low-MoI state when both are halfway between the rim and center. If passive MoI reduction is part of the key, then he must've been doing it this way for a reason, since it compromises net change in MoI within the available diameter, but also reduces transition speeds (a practical trade-off perhaps?)..
Again though, passive MoI reduction
would generate free energy - it'd be certifiably, bona fide OU, no problemo.. However it
cannot, of itself, also generate momentum - which is a second, additional and inescapable pre-requisite for any wheel directly driving applied loads from its own RKE - since that RKE has been raised without raising the net system momentum, and the only way to tap off RKE is to tap off the very momentum it is embodied in... so even if we doubled our RKE for free, we'd have to sacrifice half our system momentum in order to harvest that gain, which obviously prceludes closed-cycling unless we can source more momentum...
So aside from where the energy might be conjured from, we ALSO need to magic up a limitless source of fresh momentum - and there's no stator allowed, even internally-hidden ones - everything must, of necessity, go around together - which all seems neatly consistent with the trick being something that does both jobs at the same time, and which depends on MoI variation and the changes in speed and KE it causes. Some kind of effective violation of Newton's 3rd law, made possible by vertical rotation in a gravity field, somehow...
Which is bashically what this thread's about, near as i can tell...