• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Perpetual motion machine examination rules, please.

Psiload said:
...But if you're operating under the notion that they somehow demonstrate the possibility of squeezing bood out of a turnip, then I'm sorry to inform you that you're urinating into the wind. No advanced degree is required to recognize this most obvious fact.
It doesn't matter how many letters you've got after your name, or how many framed degrees you've got haning on your 'I love me' wall, and it makes no difference how advanced and fancy a computer program you're using to churn out sexy looking charts and graphs, if your notions aren't rooted in reality then it's all just an exercise if futility...
Click to expand...

There are many examples of this is the commentary each week!
I completely agree.
 
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skeptigirl said:
'I am here', there are not many fools on this board. Your description is one of those typical absurd claims that have been used to scam people thousands of times. Give up, go somewhere else. You won't find takers here.
...
Click to expand...

"I am here." has not posted on this Forum since Dec. 14, 2005, skeptigirl.



Also, since this thread obviously does not deal with Challenge related issues anymore, perhaps someone - you, Gene? - might want to start a new thread in the "Science..." Forum.
If a sensible, productive discussion is the aim of the participants, the thread and the "Science..." Forum would most likely benefit from a relocation, i.e. new beginning.

0,02 €
 
  • You posted not-very-pretty pictures (my 2nd year ET student son does better)
Someone mentioned they were pretty; I have no opinion about it.

  • Well, gee whiz- I can do the same thing in MathCAD, or even Excel by assuming frictionless. The pendulum accelerates down, decelerates back up, then accelerates down...ad infinitem.
That's a close description but it actually would accelerate upward; the acceleration would happen when it was at the bottom and slowing down; it would do a vertical lift. wm2d tracks the system cog and the direction was evident.

  • Give us the sim.
I've thought about the motion and although I haven't reproduced the model I think I might be able to.
  • I do simulations for a living--and I can pretty well make any kind of pretty pictures you want.
You can down load a demo copy of wm2d. I'd be impressed if you could get that amount of energy out of a pendulum swinging on a 2 meter radius with a weight of around 35 kilos. You might give it a shot before you say you can.

Gene
 
davefoc said:
I took a look at wm2d but it looks to be wildly expensive. I did download the demo package but I hesitate to even spend the time to install it if the demo package is so defeatured as to be useless.
Click to expand...

Dave,
The main feature you don't have with the demo is the ability to save models. It depends on what you're doing. When I'm looking at something I put my machine on standby.

There are packages that run on linux that are rather powerful and are free; 3d packages that you can model anything you could imagine. I haven't used any but I'm seriously considering it.

Gene
 
Wavicle,

I apologize for this quote; you were actually right. I'm still trying to reproduce that model.

  • Also, your graphs show a common artifact called "aliasing."
It might appear to be aliasing because of the compression of the data. What you call two pixels is a cycle. That pattern you notice between the cycles isn't the composite of different forces or frequencies; it's a difference in the slope of the cycles.

Gene
Click to expand...
 
GzuzKryzt said:
"I am here." has not posted on this Forum since Dec. 14, 2005, skeptigirl.



Also, since this thread obviously does not deal with Challenge related issues anymore, perhaps someone - you, Gene? - might want to start a new thread in the "Science..." Forum.
If a sensible, productive discussion is the aim of the participants, the thread and the "Science..." Forum would most likely benefit from a relocation, i.e. new beginning.

0,02 €
Click to expand...
Thanks, I realized after I posted that what I thought was a new thread was a bumped thread with 10 pages. I wasn't paying attention I guess. Anyway, I'm pleased with the forum I found anyway. I have an idea kicking around that it gave me motivation to pursue a bit more.
 
AgingYoung said:
If you don't mind me asking do you have an engineering background ....mathematics and/or physics? Are you familiar with cad programs? ...possible problems there might be in the graphs I've posted?
Click to expand...

I'm guessing your CAD package is using a discrete time approximation to simulate the system's evolution. Do you know what integration method it is using, and whether that is appropriate for your system? If not, then I suspect your design is exploiting the approximations in order to appear as if it were a perpetual motion machine. I'm sure you'll agree that reality is not an approximation :)
 
nathan,

img2.gif


Kutta-Merson?

  • I'm sure you'll agree that reality is not an approximation

I would agree that reality is independent of our thoughts and ideas of it. The pendulum I made would boot strap itself off the bottom. You can't imagine how frustrating it is trying to replicate it. I've since found out how simple it is to document a model. I could have saved the coordinates, mass, etc. in a simple text file. Although it would have been tedious to reconstruct the model from that file it would have at least been a collection of the facts. I am so frustrated.

Gene
 
I once tried to make a PMM out of Lego back when I was a kid, I tried the old unbalanced wheel method as well as lots of wierd things involving ball bearings.
None of them worked.

I did learn a lot however by trying it.

It seems you have gotten to the 'it doesn't work stage' but have yet to actually learn anything..

What does it mean to you that you can make models of these machines in a computer but none of them actually work in the real world?
 
moog,

Thanks for sharing. Who knows, with any luck I might be able to retrace the steps of your understandings and hopefully one day come up to your level. Again, thanks for sharing.

Gene
 
moog,

I did have a thought about your childhood learning experience with legos. Did you ever try to make an internal combustion engine with legos as a child? I wonder what you might have learned.

Gene
 
AgingYoung said:
moog,

I did have a thought about your childhood learning experience with legos. Did you ever try to make an internal combustion engine with legos as a child? I wonder what you might have learned.

Gene
Click to expand...

My lego set was not complex enough to do something like that.
It does seem like something I would have tried if I could though.

I have a sudden urge to buy a new set now :)
My old Lego got lost along the way...
 
I've reconstructed the details that were responsible for the self sustaining pendulum. The aliasing that Wavicle pointed out are various levels of kinetic energy; there are 4 levels.

The point that rwguinn made ....
  • Well, gee whiz- I can do the same thing in MathCAD, or even Excel by assuming frictionless. The pendulum accelerates down, decelerates back up, then accelerates down...ad infinitem.
... doesn't quite explain the relationships. A normal pendulum has kinetic energy peaking at the bottom of it's swing. That kinetic energy moves the pendulum up on it's swing and is transferred to potential energy as Wavicle pointed out
  • If you keep everything the same, but make the time scale ten times wider (so that 600s is 1500 pixels wide instead of about 150) you'd probably see exactly what we would expect to see: a harmonic exchange of kinetic to potential energy and back again.
There is a harmonic exchange with two overtones. The pendulum was dancing in a vertical lift to the tune of those harmonics. Thanks Wavicle for pointing me to an understanding of what I was seeing. You should seriously consider getting another leggo set.

When I first modeled this idea I hide most of the mechanism and only showed the mass as it was swinging. I was very amazed to see it lift itself off the bottom. That was part of the problem of reconstructing the mechanism. I spent quite a lot of time looking in the wrong place. As several people pointed out the idea that the bearing (pin) friction was zero contributed to the effect. I was looking at something else when I noticed that effect and have been seriously derailed from that effort. I don't disagree that a zero pin friction helped produce what I saw. If I had modeled that original idea precisely as I imagined it I would never have seen this. It was interesting but I don't think it has the merit I first thought it did. Trying to control that motion would be a nightmare in the real world.

GzuzKryzt,

Thanks for the birthday wishes. :) I noticed your suggestion of starting a thread in the science section. When I first saw this pendulum I was seriously considering that very thing. A problem with the idea of starting a thread is that it takes a lot of time if you take it seriously. I'd rather spend that time in search of perpetu*woo*motion. There is some value in...
  • All talk, no build.
The discussion led me to an understanding of what I was seeing. It was a very wild model even though I accidentally stumbled to it. I have two ideas that I want to try to model that I'm more interested in. I am glad that I came to an understanding of what I was seeing.

Gene

edit: spelling
 
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chran,

chran said:
Gene, happy birthday! :D

Sounds like you need some love - here's hoping your machine starts working! :cool:
Click to expand...
I was wondering what all that birthday noise was. :) I tried to change it at the control panel and noticed this again...

  • Your date of birth and age are displayed in several places on the forum. Only the administrator will have access to your date of birth should you choose to hide it via the privacy option below.
    Please contact the Administrator if your date of birth has changed.

I found that bold text particularly funny. See, anything's possible.

Gene
 
Go for it, Gene.

We wish you all the best. And we do not want to impart any pressure. Except if that's what you'd need to make your PM work.
 
Wavicle,
I looked at harmonics when I studied electronics (1/2 wave antennas, etc.) but I did a review at wikipedia when you mentioned the idea. I followed a link to Overtone singing and learned that people can produce...
  • allows the singer to create more than one pitch at the same time, with the capability of creating six pitches at once

Closed_Pipe.JPG

Some time ago I was listening to Willie Nelson sing and it seemed to me that there were three voices at once, which at the time seemed a little far-fetched. I guess it isn't. I managed to produce those harmonics in my voice during normal conversation but never knew what was happening. I could hear them and noticed a change in the expression of the person I was talking to.

The latest stint in this thread has been very interesting for me. Thanks everyone.

Gene

thanks, GzuzKryzt.
 
AgingYoung said:
Wavicle,
I looked at harmonics when I studied electronics (1/2 wave antennas, etc.) but I did a review at wikipedia when you mentioned the idea. I followed a link to Overtone singing and learned that people can produce...
  • allows the singer to create more than one pitch at the same time, with the capability of creating six pitches at once

[qimg]http://upload.wikimedia.org/wikipedia/commons/d/d7/Closed_Pipe.JPG[/qimg]
Some time ago I was listening to Willie Nelson sing and it seemed to me that there were three voices at once, which at the time seemed a little far-fetched. I guess it isn't. I managed to produce those harmonics in my voice during normal conversation but never knew what was happening. I could hear them and noticed a change in the expression of the person I was talking to.

The latest stint in this thread has been very interesting for me. Thanks everyone.

Gene

thanks, GzuzKryzt.
Click to expand...

That is fascinating. Thank you.
 
AgingYoung said:
[qimg]http://wwwasdoc.web.cern.ch/wwwasdoc/shortwrupsdir/d202/img2.gif[/qimg]

Kutta-Merson?
Click to expand...

That's a first order differential equation. Furthermore the web page you've copied that from appears to be a numerical approximation library for same. You'll notice H0 is the step length.

IIRC you'll need at least 2nd order equations. Regardless of which, my question is whether f is integrable analytically and whether your CAD package does that? Or does it perform a numerical approximation?
 
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