Perpetual Motion Device

[Eeezee]

I already know why this doesn't work, but I thought it was interesting regardless.

So take two very large plates, one with a positive charge and one with a negative charge. In other words, an enormous capacitor.

Inbetween the plates, place a wheel of positive charge. The top half of the wheel is exposed to the electric field, the bottom half is always passing through a hollow spherical conductor.

If you understand E&M, then you know that there is no electric field if you are inside a hollow spherical conductor. So in other words, there is an electric field acting on the top half of the wheel to make it spin. The bottom half is inside the hollow conductor, so there's no electric field and thus no opposing torque.

Wrong of course, but an interesting idea, right?

 

[PottedMeat]

i dont follow your description - where does the hollow spherical conductor come in?

is this what you mean? sorry about the crappy drawing

(+ side)
++++++++++++++++
____________________
_____
/ +
|WHEEL|
\ + /
____________________
----------------------------
(- side)

 

[Cattlegod]

care to draw your diagram in ms paint or something?

 

[Heisenberg]

Interesting if you don't know E&M I guess.
By having the wheel pass through the spherical conductor the surface would no longer be closed, which means the eletric field inside would no longer be zero. I've never really seen a problem like what you described, but it must work out the fields and charges present in the bottom half would oppose the torque from the top half such that no net work is done. Either that or the motion of the wheel would influence the charge distribution on the capacitor plates and require work to keep them charged. Without doing the problem I'm not sure what exactly would happen, but it wouldn't be perpetual motion.

 

[The Boston Dangler]

Perpetual motion is not possible. Any device you dream up will have some loss. Even that water-bird thing.

 

[TuxDave]

I think the fact that you have a wheel that can go through a closed surface is more impressive than your perpetual motion device.

 

[The Boston Dangler]

Originally posted by: TuxDave
I think the fact that you have a wheel that can go through a closed surface is more impressive than your perpetual motion device.

lol yep

 

[PowerEngineer]

Originally posted by: Eeezee
...there is an electric field acting on the top half of the wheel to make it spin...

A wheel (whether charged or not) suspended (horizontally or vertically) between charged plates will not experience any torque and therefore not spin.

 

[MrDudeMan]

yeah this really isnt interesting at all since its completely wrong

 

[ox1111]

Perpetual motion or endless energy devices are intrusting to think about I ponder them often. It is more important to have open state of mind when thinking about them, same as most fields of science. An endless energy source need not be self powered. If a machine or proccess runs on an endless fuel like solar power would that not be perpetual at least to mankind. There are other endless energy sources we just have not discovered them yet or have little or no concept of their power or a way to harness them.

 

[smack Down]

Isn't the universe a perpetual motion device?

 

[sdifox]

Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

 

[Eeezee]

How is it not interesting? If not for the problem with the spherical conductor not being a closed surface, this would be awesome.

If you could have all positive charge on the top and all neutral or negative charge on the bottom at all times, the wheel would spin eternally.

 

[MrDudeMan]

Originally posted by: Eeezee
How is it not interesting? If not for the problem with the spherical conductor not being a closed surface, this would be awesome.

If you could have all positive charge on the top and all neutral or negative charge on the bottom at all times, the wheel would spin eternally.

*ahem*

Originally posted by: PowerEngineer

Originally posted by: Eeezee
...there is an electric field acting on the top half of the wheel to make it spin...

A wheel (whether charged or not) suspended (horizontally or vertically) between charged plates will not experience any torque and therefore not spin.

 

[smack Down]

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

 

[silverpig]

This isn't even a very good perpetual motion machine. You'd have loss in the bearings of the wheel at least. It's basically the same as:

1. Take a wheel, roll it across a flat surface. Perpetual motion.
2. Take a really bouncy ball and drop it on a hard surface. Perpetual motion.

Sure, both situations are examples of perpetual motion, but only if you neglect all forms of friction and heat loss just as you are doing.

 

[MrDudeMan]

Originally posted by: silverpig
This isn't even a very good perpetual motion machine. You'd have loss in the bearings of the wheel at least. It's basically the same as:

1. Take a wheel, roll it across a flat surface. Perpetual motion.
2. Take a really bouncy ball and drop it on a hard surface. Perpetual motion.

Sure, both situations are examples of perpetual motion, but only if you neglect all forms of friction and heat loss just as you are doing.

/thread

 

[Inspector Jihad]

anti-friction is the answer to perpetual motion. A force that acts like the opposite of friction but pushing an object along. yup anti-friction

 

[sdifox]

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

 

[remagavon]

nm

 

[smack Down]

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

 

[klah]

Originally posted by: smack Down

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

Read Dr Steinhardt's paper in Science(vol 296) "A Cyclic Model of the Universe."

 

[ruffilb]

Originally posted by: Bigsm00th

Originally posted by: silverpig
This isn't even a very good perpetual motion machine. You'd have loss in the bearings of the wheel at least. It's basically the same as:

1. Take a wheel, roll it across a flat surface. Perpetual motion.
2. Take a really bouncy ball and drop it on a hard surface. Perpetual motion.

Sure, both situations are examples of perpetual motion, but only if you neglect all forms of friction and heat loss just as you are doing.

/thread

 

[Skyhanger]

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

Goto wikipedia.com and read "entropy" the universe may keep on expanding, but one day it will pretty much be homogeneous soup of matter and space w/ no energy gradient across it...

 

[smack Down]

Originally posted by: Skyhanger

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

Goto wikipedia.com and read "entropy" the universe may keep on expanding, but one day it will pretty much be homogeneous soup of matter and space w/ no energy gradient across it...

Go look up relevant. You might also want to check out acceleration and velocity while your at it. F=ma what force is going to stop a galaxy that is moving outwards really fast?