Big try at gravity wheel

[Marsing]

@markE

I think I found it,

Marsing, I don't know why Grimer finds that dim video of a motor demonstration so fascinating.  The narrator showed the motor starting up and running.  I didn't hear the narrator saying anything like the motor didn't need a power source.

you are joking,  din't find something interesting.
pay attention to  the motor not narrator.

Did the builder ever say that motor did anything remarkable?

narrator said something that should be Noticed, "  now, i gonna stop ....".

(just my opinion).

[MarkE]

@TinselKoala, that sounds sad.

@Red_Sunset, I see.  He's made it very clear that he doesn't want to state a hypothesis, and he's contradicted the best effort I could make to state one from what he's said.  So maybe Plan D is best all around.

On the cycloid chop thing, the original idea from Grimer was that the circular path had more energy at its apogee than the cycloid at the same height.  Whether one or the other has more energy we could determine by finding the maximum velocity at the bottom of the travel.  Both types of pendula swing freely at the bottom and no one has suggested some alternate energy source, sink, or store at that point of the travel.  So, we could do several things:  We could construct pendula experiments using our best approximation for a point mass and a perfectly flexible and mass-less arm.  Then we could see if there is any detectable difference in maximum speed at the bottom of the travel.  Or we could go through the math and calculate the expected velocity and energy at each point of the swing.  I don't have time to do that for the cycloid tonight, but it does not seem a particularly difficult task.  Of the several issues that I found with Grimer's idea that there is some "ersatz energy" captured and released by the circular pendulum is that Grimer seemed to ignore that tension in the arm goes to zero as the bob reaches its apogee.  He seemed to talk as though he thought the "ersatz energy" was associated with centripetal / centrifugal force on the arm, when at the instant the bob reaches apogee there isn't any radial force.

To answer your question:  the cycloid path is steeper than a circular path so the acceleration / deceleration is more pronounced away from the center.  That accounts for the cycloid having a shorter period than the circular pendulum of equal apogee.  An alternate way to look at this is use low friction tracks and rolling balls.  If we arrange various tracks with equal maximum heights, we turn the child's swing / pendulum into a roller coaster.  If we arrange these tracks with different curves then we can observe several things:

1) There is no curve that we can design where the ball released from one side will top the release height at the other side.
2) There will be at least one curve that results in minimum transit time from one end to the other.  300 year old math says that will be a cycloid path.
3) A track made with a cycloid path will result in the same oscillation period independent of the starting point.

3) is the fascinating property of cycloid paths.  It makes me think that the fairest pinewood derby track is one laid out as a cycloid as that would eliminate any advantage / disadvantage from slight misalignments at that starting gate.  Some parallel cycloid tracks arranged to simultaneously release balls from different starting heights in each track could make some interesting physical art.

[Grimer]

Grimer is seeking to discredit someone by posting the video. He is displaying his frustrations. He is in the same position as a child is, looking at the "disembodied head" sitting on a table in a circus booth. Everybody around him knows that the head isn't really disembodied, that it only looks that way because of the carefully positioned mirrors that make the table look like there's nothing underneath it. But he persists in exclaiming that the head is in fact disembodied, and proceeds to construct all kinds of theories and explanations for how the disembodied head came to be and why it can still talk. Even when the carny builder of the table tells the child that it is just a trick, the child persists in his fantasy belief, and tells his friends about the disembodied head that could talk. For years, the child continues to reject sensible explanations and his own common sense, and thinks he saw a talking disembodied head. Years pass and memories are plastic; eventually the child might realize his silliness.... or maybe he never does.

Are you claiming that you committed a fraud, Al. If so you are much worse than Mylow whose fraud you took such pride in uncovering.


But you won't answer my question will you. You never have in the past. You won't admit it and you are not prepared to lie. You just resort to some childish insult.


And please stop all this nonsense by referring to the builder of the WhipMag as though he is someone other than you. Readers of this forum are not that stupid. If you keep talking as though Jekyll and Hyde are two different people then members of the forum will begin to realise they are dealing with a schizo.

[MarkE]

Grimer would you please calm yourself down?  Where is this fraud you keep alleging?

[Red_Sunset]

....................................................................
  Some parallel cycloid tracks arranged to simultaneously release balls from different starting heights in each track could make some interesting physical art.

A pretty good animation that does that can be found here,
http://www.myphysicslab.com/beta/Brachistochrone.html

Click on the curve to mark the ball on that curve in comparison to the others, since they all will launch at the same time.
Red_sunset