Perpetual motion proposal for criticism

[Circlotron]

What is the flaw in the following concept?

Have a bunch of fibres or very fine tubes raise water to a height by means of capillary action, same as a tree does, to many metres high.  At the top the water overflows and on the way down it drives a water wheel or similar. Water then gets directed back to a pool from which it gets drawn up again etc.

Presumably this won't actually work because otherwise it would be in widespread usage, but why?

[KE5FX]

Capillary action creates a concave meniscus where the water adheres to the tube.  At the end of the tube there's no meniscus and no other transport mechanism, so it will never drip.

[Andy Chee]

I feel that this basic question belongs to a class of questions in which ChatGPT, Gemini or your favourite LLM, is more than capable of answering with the correct answer without hallucination.

[iMo]

And when you try with liquid helium?
 

[Haenk]

All perpetuum mobile concepts have one thing in common: They do not work.
You just can't cheat physics to gain some free energy.

[jonovid]

free energy
trees are powered by the sun. so use a solar panel to power your gadget, or what ever.
perpetual motion gadgets are magicians tricks or useless machines by magicians IMO . the best is the
magic switchbox ,  remove the battery it still works. swap the LED colors & the switchs still work.
 
challenge- explain how it works.  on another forum thread

[temperance]

trees are powered by the sun.

[SteveThackery]

What is the flaw in the following concept?

Have a bunch of fibres or very fine tubes raise water to a height by means of capillary action, same as a tree does, to many metres high.  At the top the water overflows and on the way down it drives a water wheel or similar. Water then gets directed back to a pool from which it gets drawn up again etc.

Presumably this won't actually work because otherwise it would be in widespread usage, but why?

@KE5FX has nailed it: capillary action happens at the interface between the top surface of the water and the wall of the capillary tube. Once at the top of the tube - where the wall stops - capillary action stops. It can never overflow.

[Rick Law]

All perpetuum mobile concepts have one thing in common: They do not work.
You just can't cheat physics to gain some free energy.

I don't know about that...  (If our theory of "how we come to be" is correct...)  Big Bang was free and the energy released was and remains the biggest ever energy release in our universe. Our universe has lasted quite a while with this free energy from random fluctuation.  We are here because our universe started with a cheat.  It will eventually die of heat-death, but given time another bang will occur. 

You can cheat when you put quantum effects into consideration.  How we can do that, if ever, is to be determined.

[SteveThackery]

Big Bang was free and the energy released was and remains the biggest ever energy release in our universe. Our universe has lasted quite a while with this free energy from random fluctuation.  We are here because our universe started with a cheat.  It will eventually die of heat-death, but given time another bang will occur. 

I think it's important to distinguish between free energy and over-unity energy. We are surrounded by "free" energy - solar radiation, for example - although there is cost in harvesting it. Over-unity is energy created from nothing. That breaks the known laws of physics, but gets certain people excited all the same.

[paul cotter]

On the subject of the big bang: I have heard the argument from the late S Hawking that the net energy of the universe is zero with the positive mass/energy cancelled out by the negative gravitational energy. My physics is not good enough to test this assertion but if true it means there was no "creation" to speak of.

[Electrodynamic]

What is the flaw in the following concept?

Have a bunch of fibres or very fine tubes raise water to a height by means of capillary action, same as a tree does, to many metres high.  At the top the water overflows and on the way down it drives a water wheel or similar. Water then gets directed back to a pool from which it gets drawn up again etc.

Presumably this won't actually work because otherwise it would be in widespread usage, but why?

It is theoretically possible but not practical. A tree uses transpiration which is a fancy way of saying the leaves evaporate water creating a temperature drop and negative pressure within the biological material it's made of. In effect, it's just another form of heat engine not overunity or perpetual motion.

Here's a new twist on your idea, https://www.technologyreview.com/2017/09/26/148952/evaporation-engines-could-produce-more-power-than-coal-with-a-huge-caveat/
Why try to move water up something like a tree when we could harness the energy of evaporation directly?. With nanotechnology or engineered materials it could be possible in the future imo.

[racemaniac]

Regarding the original idea of using a capillary action, as others said, it doesn't overflow like that.
But even the height the water gains is deceiving.
In the end, all capillary action means is that the attraction between the water and the wall of the tiny tube is so strong that the water level rises in the tube.
But like always, that's not free energy. Instead of spending the amount of energy to raise the water up, you'll now have to spend at least an equal amount of energy to get the water to let go of the wall of the tube. Because that's why its level rose, there's a strong attraction to the wall. And it can also only rise as high as there is equivalent amount of attraction to the wall to overcome that gravity compared to the water level of the basin you put the tube in... So you didn't get any free energy at all, you just changed the kind of work you have to do (from lifting the water up, to overcoming its attraction to the wall of the tube), but you still have to do equal amounts of it to get the same result .

[rfclown]

we've got some smart people on this forum. I've heard the word "meniscus", but it isn't in my vocabulary, and I didn't know the mechanism of capillary transport in plants.

[Rick Law]

Big Bang was free and the energy released was and remains the biggest ever energy release in our universe. Our universe has lasted quite a while with this free energy from random fluctuation.  We are here because our universe started with a cheat.  It will eventually die of heat-death, but given time another bang will occur. 

I think it's important to distinguish between free energy and over-unity energy. We are surrounded by "free" energy - solar radiation, for example - although there is cost in harvesting it. Over-unity is energy created from nothing. That breaks the known laws of physics, but gets certain people excited all the same.

I think it is a distinction without a difference -- there is no reason be believe that energy conservation, or the laws of thermo-dynamics can be applied as is outside the classical physics (micro-meter to solar system size) realms.  Shrink it to quantum scale, it allows things that isn't allowable in classical physics realms.  Expand it to galaxy size, we now know even gravity works different.  We kludge it with dark matter, but at best it is just a patch work for now.  Shrinking it all the way down to Planck scale, we have no firm knowledge.

Laws of Physics is just "as far as we can tell for now."  It can change, and it will change as we learn more.  There is a lot of learning more yet to be done.

So I am not at all comfortable with a declarative statement that "perpetual motion is impossible."  I would qualify the statement a bit, such as "Present day understanding is..."  That may even encourage more kids with curiosity into science -- it is a world of discovery rather than a prison of merely understand facts already written down in books.

Edit: Corrected typos

[booscrawl]

There is something kind of vaguely similar to this: if you launch a spacecraft from the equator, it actually steals kinetic energy from Earth's rotation, making it less energetically expensive to go to space. The closer you launch to the equator, the closer to the maximum added velocity you get; the further, the less free velocity you get. Unfortunately, gravity is so strong (and the Earth's rotation so slow) that this "centripetal energy exchange" doesn't really work on the scale of a tree.

[Electrodynamic]

Rick Law

So I am not at all comfortable with a declarative statement that "perpetual motion is impossible."  I would qualify the statement a bit, such as "Present day understanding is..."  That may even encourage more kids with curiosity into science -- it is a world of discovery rather than a prison of merely understand facts already written down in books.

The concept of perpetual motion is often misunderstood imo.

For example, many think nuclear power comes from uranium but where did the lump of grey metal get it's energy?. We find all the heavier elements and the energy they contain were created from collapsing stars and supernova billions and billions of years ago in some other part of the universe. By comparison our average life span is maybe 70 years and hundreds of millions of times shorter in duration. It's kind of wild knowing that the "energy" powering our lights or computer was transformed billions of years ago in some other part of the universe before mankind even existed. It's pretty damn close to perpetual motion imo.

Another apparent contradiction is the big bang theory. If we actually believe in the conservation of energy then we must also believe the universe was compressed prior to expansion/big bang and operates cyclically. Otherwise were talking about creation and something from nothing like overunity. One would think anything defined as "cannot be created or destroyed only transformed" must be perpetual. AI claims, "Yes, energy is never‑ending in the sense that it never disappears". However many confuse this with entropy and diffusion where energy transforms to heat and becomes less useful. Were not talking about how useful energy is more so about whether it is perpetual or not. It appears energy is in fact perpetual by definition and cannot be created or destroyed, case closed.

[paul cotter]

Energy conservation holds locally but not on very large scales. The expansion of the universe results in the red shift which is a loss of energy.
As regards perpetual motion, it is quite possible IN PRINCIPLE if all loss mechanisms are eliminated. Perpetual motion supplying energy is of course totally ruled out, in principle and in practice. If the laws of thermodynamics did not hold, locally, we would not have the stable universe which we inhabit.

[IanB]

What is the flaw in the following concept?

Have a bunch of fibres or very fine tubes raise water to a height by means of capillary action, same as a tree does, to many metres high.  At the top the water overflows and on the way down it drives a water wheel or similar. Water then gets directed back to a pool from which it gets drawn up again etc.

Presumably this won't actually work because otherwise it would be in widespread usage, but why?

If any mechanism like this worked, it would in thermodynamic terms be a "heat engine", which would take the flow of heat from a hot "source" to a cold "sink" to produce some mechanical work along the way.

So without any external heat source, the system would cool down until eventually it became so cold it would stop working.

With a heat source, then of course it would work continuously, but there would be nothing strange about this.

[Rick Law]

Energy conservation holds locally but not on very large scales. The expansion of the universe results in the red shift which is a loss of energy.
As regards perpetual motion, it is quite possible IN PRINCIPLE if all loss mechanisms are eliminated. Perpetual motion supplying energy is of course totally ruled out, in principle and in practice. If the laws of thermodynamics did not hold, locally, we would not have the stable universe which we inhabit.

First, a side comment.  I found looking at the edge is often when we learn unexpected and useful knowledge.  Thus I often dig around the edge...

I agree largely with what is said in the quote.  There are unsettling aspects to "expansion of the universe" that I don't yet feel right.  It is more a "new space being created" rather that "space expanding".  There is a difference there.   "Space expanding" would imply that Planck length is longer.  "New space created" doesn't lengthen Planck length, but may imply a different energy requirement.  I think the resolution is incomplete thus far.  I think at least some physical constants has to change -- big G, C, and some other things has to change.  Writing about my reservations is a waste of time.  My rants would not interest anyone.  "Big Crunch" would have been a very satisfying answer (everything is conserved), but that is now replaced by infinite expansion ending with a heat-death.

With larger than LHC and String Theory now receding into the background.  Exciting time in Physics is coming.  I hope in my life time, I can at least see the direction of this new Physics paradigm shift.  Physics needs a paradigm shift like someone needing fresh air after a walk in the fish market.

[SteveThackery]

"Space expanding" would imply that Planck length is longer. 

I don't think that follows. None of the three constants that define the Planck length are changing, as far as we can measure. I think the term "expanding" might be insufficiently precise - in common use it can mean "stretching" something or "more of" something. When it comes to space we probably need to be more explicit about what "expanding" actually means.

But, going back - I don't see why "stretching" space would have to alter the Planck length. It's sometimes described as the scale at which spacetime itself may become "grainy" or lose its smooth, continuous character, but this remains entirely speculative. Right now it is simply the smallest unit of length in physics.

[paul cotter]

All we know for sure is that part of the universe which we can observe is expanding. We do not know if it is expanding into "non-space", whatever that might be. I would be in agreement with Steve that this expansion does not need changes to constants. I am probably not the best person to be arguing these points as I am just a retired engineer and not a physicist/astrophysicist.

[Electrodynamic]

Energy conservation holds locally but not on very large scales. The expansion of the universe results in the red shift which is a loss of energy.
As regards perpetual motion, it is quite possible IN PRINCIPLE if all loss mechanisms are eliminated. Perpetual motion supplying energy is of course totally ruled out, in principle and in practice. If the laws of thermodynamics did not hold, locally, we would not have the stable universe which we inhabit.

I would disagree and see the conservation of energy as an absolute which cannot be violated.

Energy cannot be created or destroyed only transformed. Suppose the heat from our truck enters the atmosphere. Heat is not something more so a measure of how fast atoms jiggle. So the jiggling heat energy is transferred to other stuff and some of the jiggling causes EM waves. Some of the EM energy leaves the Earth and could travel any distance until it is absorbed by another material thing causing it to jiggle a little faster than it was before. The problem seems to be we cannot track a single packet of energy on it's journey as it moves from one thing to another constantly changing form perpetually. However the science we know is very consistent that energy is always conserved no matter how many times it moves from one thing to another or changes form. In my view to say energy disappeared is no different that saying it appearing out of nothing, it doesn't work.

In my view the COE relates directly to perpetual motion. We have already defined heat as a measure of how fast atoms jiggle thus we know it is kinetic in it's nature. Some jiggling heat energy leaves a group of atoms transformed into jiggling EM fields which is imparted to other groups of atoms making then jiggle a little faster. We can say it changes form but we can track the motion. Matter jiggles a little faster, then the EM waves jiggle faster which is absorbed by other stuff causing them to jiggle faster. Key word, "jiggle" which implies the "motion" or change of something. We could use any terminology we want other than jiggling however the principal of the conservation of energy relating to motion must always hold imo.

[themadhippy]

I would disagree and see the conservation of energy as an absolute which cannot be violated.

people said the same about traveling faster than a galloping horse

[IanB]

I would disagree and see the conservation of energy as an absolute which cannot be violated.

Conservation of energy has only been verified on the local scale that we inhabit. If we compare our local scale with scale of the universe as a whole, it is rather similar to comparing the macroscopic scale to the quantum scale we can observe locally, where our world might be at a "quantum" scale relative to the universe.

So we cannot be certain that our local experience is the same at the scale of the universe. How do we know, for example, that there isn't a place "outside" the universe that can exchange energy into and out of the universe?