Wheel acceleration...

[daxwc]

That is strange... I wonder what happened at around the time the wheel was to bang (falling weight) or did it not make any noise going slow?

[DrWhat]

Hmmm, interesting. I think the key word here (if accurate) is "always" (stood still...). This implies many small successive yet separate pushes would not yield accelerative rotation, not just one small push when the wheel sat in balance.

Fascinating. What kind of mechanism would do that. Reminds me of a vehicle's torque converter.

Makes sense though in a bi-directional wheel.

[Fletcher]

Unfortunately we don't know whether he gave it a small series of quiet pushes one after the other, though that seems to be implied - that is, he may have moved it on two or three times & then given it a tolerable shove that caused it to gain velocity & then he had to forcibly stop it - if you take this to the extreme then you can imagine he could have rotated the wheel thru 360 degrees with a series of small pushes & each time he took his hand off it stood still [balanced] in its new position without back rotating - he then could have reversed the process in the opposite direction with the same result - it seems incomprehensible that it could always be balanced in any position in any direction & he certainly didn't say he conducted a test like that, so it is likely IMO that he quietly moved it at least a couple of times in succession to form that observation of at least initial balance [& thought it important enough to mention it to Newton].

If we assume that the bi-directional wheels had dual overbalance mechanisms, each arranged to create overbalance in the opposite direction to the other [N.B. the sound of about eight weights gently hitting on the descending side ; which must have occurred on both sides of the wheel depending on its direction of rotation], then it's a bit of a stretch of the imagination to see how this might occur - it would mean that the system not in use would have to be latched in a neutral symmetrical position as the wheel rotated but as soon as it was stopped & the direction reversed it was free to deploy & immediately provide the counter-torque to balance the wheel - this would mean that effectively the wheel was initially balanced until the now redundant system was all neutralized [symmetrically positioned & just a rotating inertial mass inside the wheel], until the wheel was stopped & the direction was reversed again.

A couple of observations :

1. It is much easier to accept that 'sGravesande was wrong & it wasn't balanced when he took his hand off, though this man was professional & methodical in the rest of his report, so this seems unlikely - if he were wrong or mistaken then it is far easier to imagine an unbalanced system needing a shove to get it past the threshold where it had positive torque again to accelerate the wheel - we are all very familiar with these OOB systems.

2. That the translation of 'always stood still' is not an accurate translation or is insufficiently detailed to conclude that it meant 'immediately stood still' once his hand was removed ?

3. That the system was always balanced, however I think it more likely that it was initially balanced [thru a range of degrees] until the redundant system was at least partially neutralized, which would have given the impression of initial balance in any position, unless a 360 degree test was conducted to say conclusively otherwise.

4. That regardless of whether you believe the translation of 'sGravesande is correct that it is certain that the wheel needed to reach a predetermined threshold of velocity before it could accelerate away - if the wheel was always unbalanced, partially balanced for some of the time, or always balanced so that a force created torque directly to one side of the wheel, then it is also self evident that the wheel created a force from dynamic movement of internal components relative to the wheel that was used either to directly turn the wheel by reaction force or reposition weights inside the wheel.

[jim_mich]

, then it is also self evident that the wheel created a force from dynamic movement [over a threshold velocity] that was used either to directly turn the wheel by reaction force or reposition weights inside the wheel.

As Bessler said, his weights “gain force from their swinging motion.�

[bluesgtr44]

Dadgumit! I hate doing that when I don't have my books.....but I just wasn't sure....

More than the 2 finger push or shove crap....what impressed me more was the description by Fischer (I could be wrong)

OK, here's the part that I mentioned about it reaching max speed in less than a minute.....this was for the Merseburg wheel.

DT....pg. 244....J. Collins..."It then began to rotate of its own accord with such force that within a minute it had rotated 40 and more times, and could only be stopped by applying great effort."


Steve

[ovyyus]

As Bessler said, his weights “gain force from their swinging motion.�

Jim, don't you mean "swinging OR motion". I know you really want it to be "swinging motion", though :D

[jim_mich]

It should be "swinging/motion"!

Once again I'm heckled. I feel very strongly that it should be interpreted as just "swinging."

The German seemed to say "swinging" and the Latin seemed to say "motion" so take your pick! It seems that either one is right. I try to accommodate both points of view so as to keep people happy. :D

[Jon J Hutton]

I may really show my ignorance by this statement but what I think science needs especially in the realm of energy is a kelvin scale.. instead of work or no work being done. A magnet on a refrig is a great example. There seems that much energy is being used but not in the form of work therefore the assumtion is made that it is not useful. I think when pm is found a new scale will be born. Science will change in more than one way.

JJH

[ovyyus]

Jon, a magnet on a refrigerator is a great example of no work being done. Just like sticky tape on a frig is a great example of no work being done. Of course, it required work from someone in order to originally lift both up and onto the frig.

Jim, when I tell you that I'm swinging my cat what I really mean is that I'm throwing it, no matter how strongly you might feel otherwise.

[evgwheel]

A magnet stuck on a fridge is said not to do any work!
I see it slightly different. But than again I am not as clever as most.
Magnets have opposing fields and are circulating atoms or whatever around constantly, either rejecting or accepting other metal particles it is near or close to. So a magnet does do work as it influence other metals it is attached to and makes a change to its host. Changing anything is work being done

[ovyyus]

Changing anything is work being done

While the magnet is stuck to the frig, what changes?

[evgwheel]

In my opinion it is the property of the magnet that interchanges or configures molecules with its host constantly. Take away magnetic properties at any time of the magnet sticking to the fridge, it will fall off.

[ovyyus]

Take away the sticky properties of sticky tape and it will fall off too :D

[bluesgtr44]

pssssst...it has potential energy....

[ovyyus]

... that isn't doing work.