I think I am at the point of convincing him that the machine has a net negative energy output. (This is not an in-person discussion, it’s happening over text).
It does nothing without an input of pressurized or overhead water. A person or otter pumping water is still an energy input.
Having agreed on that, I hope to connect the dots that this is a hydroelectric system. It is in direct competition with hydro turbines and water wheels. AIUI those have an efficiency of at least 90%, so this needs to do better than that. Which – given that I calculated that it’s energy-negative even neglecting friction and viscosity, all the extra mechanisms are just going to make it even more negative.
What factor(s) make it intrinsically net energy-negative rather than net-zero?
I get the impression that even if OP succeeds in putting this guy wise to the impossibility of even his perpetual motion machine, his bridges would still fall down.
I have actually delved into this idea of an energy producing device. Quite a while back there are several posts of mine questioning aspects of buoyancy.
Even with my crappy math skills, I came to the conclusion that the pressure present at the insertion point of the buoyant body will cancel out the uplift of any bodies in the water column. I still try and perfect the calculations from time to time to see just how close one can come to 0 in the system. It is at least more intuitively seductive than the rotating jointed arm contraptions proposed for free energy. As at least there are opposite forces acting positively on each side of the gadget. Unfortunately gravity still works on the water side as well.
I enjoy imagining and then dissecting to destruction various things that are impossible, or at least so far impossible. I am inspired to return to this gadget and mentally find all the flaws.
So what is the lowest friction O ring composition?
Well, the most obvious thing is the same problem that affects every perpetual motion machine: friction (or viscosity where fluid is involved). The machine stops if the lost energy isn’t replaced.
The greater (and less obvious) problem with this specific machine is that it proposes to offset the cost of resetting the water column by recapturing the energy of the ball as it descends in air.
That can’t work because in water, the buoyant force on the ball is a function of X liters of water, while in air it’s a function of X liters of ball material. If you imagine a floaty material like styrofoam, a liter of that is obviously much lighter than a liter of water. F=ma, therefore the forces aren’t anywhere close to balanced.
That seems to be the biggest error in thinking here, the idea that buoyant force is somehow “free” just waiting to be harvested, rather than energy stored by pressurizing fluid to fill a tank, or to submerge a float under some natural reservoir. Also the notion that the water loss is negligible, and that moving water up and down, here and there, is something you get for free.
This seems to get at the objection I was trying to think of.
Think of the weights of the float and water instead of their volumes. Suppose the hollow float weight 1 oz, and has a total volume sufficient to displace 10 oz of water. So it sits at the surface, displacing 1 oz water. You need to push it down with an addition al 9 oz weight to submerge it. Altogether, this displaces 10 oz water, and that displaced water contains the potential energy you put there.
Now let the float float, as floats are wont to do. As it pops up, 9 oz water can fall down, leaving the float floating, displacing the original 1 oz water. That just recovers the potential energy of the 9 oz you had to invest to push the float down.
Now move the float off the water and drop in in the air. (Neglecting air resistance of course, because all cows a spherical.) You only have 1 oz worth of potential energy left in that float, and that’s all you’ll get by dropping it. You can never get that other 9 oz worth of energy that you wasted in pushing the float down in the water. So that’s where the massive net-energy-negative loss happens.
Note the “intuitive” phrasing above, conflating “ounces” with some kind of units of energy. You wanted “intuitive”.
Yeah, the whole idea is based on what buoyancy seems to do, rather than how buoyancy works. ‘Buoyancy makes light things go up’ is OK, but you can’t ignore the necessary ‘when, and because, a heavier thing goes down’ part.
Epilogue: the individual I mentioned in the OP is now hospitalized for a psych issue. I’m glad he’s getting help and to know he’s not dumb, just temporarily unbalanced. Wish I’d listened to my gut last week.
We often impute mental illness to those who have issues with scientific or political facts, but I don’t think very often do we think it’s literal treatable mental illnes, but rather the vernacular “you’re crazy” kind.
This is kind of a first in my awareness. I hope this individual can make a full recovery, or at least be treatable to the extent of taking control of this illness rather than it having control of him.
We’ll see. Not great at the moment. Apparently didn’t eat, drink, or sleep for 4 days, but getting proper treatment now. It was 100% treated and under control for decades, so we’re hoping things will return to that state.
He had COVID recently and I’m afraid that some baggage may have shifted during takeoff and landing, neurologically speaking. An engineer pitching an apparent perpetual-motion-machine design… I had my suspicions, but it’s not easy to ask someone if they’ve lost a few marbles, especially me not being versed enough with the basic engineering.
FWIW and I am not a psychiatrist… it sounds like a manic episode and that it was well managed for many years. With that track record there is every reason to expect that it can be gotten back under control relatively quickly. Best wishes to him and to you as his concerned friend.