Let's debunk my (very simple) perpetuum mobile

I know there must be a flaw somewhere but I can't find it so let's do it together.

It's based on changing density of object in water(or some other liquid for that matter).

Energy.JPG

here you can see a bigger ball which, when empty, has less density than water and thus floats, but in this case it's full of smaller balls (all of those are also less dense than water) which make the big ball denser than water thus it sinks, pulling the string connected to coil outside of the water tank which is then rotated and energy is produced

so when the ball reaches the bottom, a sensor activates its opening (via internal hatch or somehow else) and this is what happens

Energy1.JPG

all objects in the rectangle are now less dense than water and they all go up to the surface

then we have the next situation

Energy2.JPG
when they all come to the surface, the big empty ball is lifted and only smaller balls are staying on the surface, they are collected with some type of shovel (marked with line S) lifted and put into the big ball, the big ball is then disconnected from the "roof" and we are back at the picture 1, rinse and repeat

I can't prove if energy created would be enough for lifting the big ball to the roof and putting small balls into the big ball but I can't prove it wouldn't be either.
 

Mick West

Administrator
Staff member
a bigger ball which, when empty, has less density than water and thus floats, but in this case it's full of smaller balls (all of those are also less dense than water) which make the big ball denser than water thus it sinks

The only way adding the small balls to a big ball (let's call that the "ship) would make it more dense than water is if the ship were originally filled with air (which you are not replacing with more dense balls).

If it's filled with water, then adding the small balls would make the total LESS dense (like adding pingpong balls to an underwater ship)

If it's filled with air, then you can get it to sink by adding small balls through a small hatch in the top, but then when you release them at the bottom, then you'd fill the "ship" with water (at the very minimum replacing the volume of a ball with the same volume of water) , and it will not float to the top.

If the ship is buoyant when filled with water, then adding balls will displace the water and make it more buoyant.
 
well yes it's originally filled with air, like an empty football, then it's split open, filled with small balls and then closed

at the bottom when it gets open it gets "split" so it's not ball-shaped(I haven't spent more than a minute for those drawings heh), just an object made from material less dense than water (imagine two halves of one ball connected only at the bottom, freely moving through water)
 

Mick West

Administrator
Staff member
well yes it's originally filled with air, like an empty football, then it's split open, filled with small balls and then closed

at the bottom when it gets open it gets "split" so it's not ball-shaped(I haven't spent more than a minute for those drawings heh), just an object made from material less dense than water (imagine two halves of one ball connected only at the bottom, freely moving through water)

If it's made from a material less dense than water then it would not sink.
 

Mick West

Administrator
Staff member
Draw a circle around the combined "object" (ship + balls). What is the average density of the contents of that circle?

Unless there is some material in that object that is more dense than water, then the circle will not sink.

And you also need to counteract anything that is less dense than water.

Imagine a styrofoam cooler. It floats. If you add more styrofoam to it it's not going to sink. You have to fill it with bricks.
 
umm OK let's not get that far, imagine 1 liter ball weighing 900g, it has 900g/l density, it floats because water has density of 1000g/l

now if you fill that ball with 200g of small balls then it will have 1100g/l and it will sink, no?
 

WeedWhacker

Senior Member
I still think there is that old "nemesis".....friction. Also, water has a surface tension which will rob energy from the system.
 

Mick West

Administrator
Staff member
umm OK let's not get that far, imagine 1 liter ball weighing 900g, it has 900g/l density, it floats because water has density of 1000g/l

now if you fill that ball with 200g of small balls then it will have 1100g/l and it will sink, no?

No. The average density (of the entire composite object) is still less than water.
 

Mick West

Administrator
Staff member
I still think there is that old "nemesis".....friction. Also, water has a surface tension which will rob energy from the system.

Nothing to do with the root problem here though. Friction would rob energy, but there's no extra energy to rob anyway.
 

Mick West

Administrator
Staff member
It might be simpler for you to realize the problem if you consider the entire experiment conducted underwater, to remove the confusing factor of air.
 

WeedWhacker

Senior Member
Isn't the effect of gravity imparting some energy in this thought model? What would happen in a free-fall/micro-gravity environment?
 
I still think there is that old "nemesis".....friction. Also, water has a surface tension which will rob energy from the system.

well of course there would be some losses here and there, as in "conventional" machines too, the question is why would they have to be bigger than gains

No. The average density is still less than water.

nope, imagine it again and you will see, empty ball has 900 g/l density, filled one has 1100 g/l density, there is a big difference if it's only air in the ball or some heavier stuff
 

Mick West

Administrator
Staff member
nope, imagine it again and you will see, empty ball has 900 g/l density, filled one has 1100 g/l density, there is a big difference if it's only air in the ball or some heavier stuff

Before: Ball + water
After: Ball + small balls + water - (volume of water equal to small balls)

The "After" has a smaller density.

You are thinking of "the ball", but part of what you are saying refers to the composite object, and part just to the material in the ball.
 

NoParty

Senior Member.
I began thinking it was another doomed perpetual motion device.

Now I'm 50% sure it's headed towards a punchline
that involves the terms "friction," and "small balls"
 
oh there is the flaw :D now if only it could be possible to kick the small balls out at the bottom without water entering in, but I doubt water pressure would allow it
 

Mick West

Administrator
Staff member
When I was young I invented a perpetual motion machine. It's a 1km tall pipe filled with water. You have a door at the bottom, and you open it and insert a large wooden ball. The ball floats to the top. You then take the ball and put it on some conveyor type thing that turns a generator as the ball descends to the bottom. Repeat. Infinite free energy.

Your idea reminded me of that. :)

 

WeedWhacker

Senior Member
It's a 1km tall pipe filled with water. You have a door at the bottom, and you open it and insert a large wooden ball.

Hmmmm.....OK. You open a door at the bottom, and somehow keep one kilometer of water above not rushing out? (Takes a bit of "energy" to accomplish, no?).

Creative, but now.....how do we extract any usefulness from it? In terms of, say....electrical power generation?
 

Mick West

Administrator
Staff member
The thing about all these mechanical free-energy devices is that they can't possibly work. So the fun is all in figuring out how.

@veproject1 has a lot of cool videos of things he made along these lines. I banned him a while back as his videos were confusing people as they kept thinking they were genuine claims and he didn't want to fess up. I'll lift the ban for now, see if he feels like coming back.
 

NoParty

Senior Member.
When I was young I invented a perpetual motion machine. It's a 1km tall pipe filled with water. You have a door at the bottom, and you open it and insert a large wooden ball. The ball floats to the top. You then take the ball and put it on some conveyor type thing that turns a generator as the ball descends to the bottom. Repeat. Infinite free energy.

Your idea reminded me of that. :)

My god! I bought a device in February that looks identical to this drawing, from the good folks at Fix The World!!

And after just 2
($300) phone calls we got the top ball-loader sorted, and after just 3 more ($300) calls
the "metal plate/hatch assembly" is nearly trouble free.
Currently rockin' .83 unity, but overunity a certainty by Thanksgiving!

(I already cancelled my power company service!)
 

Pete Tar

Senior Member.
If you sealed the top when the hatch below opens, would the water be held in place like with a straw?
 
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