energy derived from differential specific gravities?

It released MORE than the first, yes. But the first still has ALL the energy you put into it. The second does not have all the energy you put in it, since the denser water moved down to the bottom (lower potential energy).

It's like lifting two bowling balls up and putting one on a flat surface, and the other ball on a slope. Let both go and the second bowling ball releases energy, while the first does not. All you've done is set up a situation where energy can be released with one ball, but not with the other. Same with the pipes.

Dave

Well, I can't tell if you're kidding, but I'm going to assume you're not.

The venturi effect requires a fluid velocity to create a pressure difference. There's not really any real velocity with the situation you describe. I think you mean just the basic air pressure difference between the ground and space? If that was the case, why do you need a tube at all? Why doesn't the air just rush out into space? Answer: gravity. The air pressure on the earth's surface is due to gravity, and air can't be sucked out into space because the energy required to lift it is more than the energy you can get from the pressure difference.

Dave

It doesn't. All you've done is contrive to extract a little of the second's (smaller) total energy before releasing the rest. Just to make it concrete, we'll toss in some numbers pulled out of a hat.

Pipe 1:

1. Insert 4.0 J of energy to fill pipe
2. Empty pipe and extract 4.0 J of energy

Pipe 2:

1. Insert 3.8 J of energy to fill pipe
2. Let water and oil trade places and extract 0.3 J of energy
3. Empty pipe and extract 3.5 J of energy

PD

This example actually does not contain a Maxwell's Demon. It is, as is always the case, a flawed attempt to exhibit perpetual motion. In this case, as with many others, the flaw is that the system is not closed.

Here on Earth, we have many sources of potential energy. Every apple in a tree has gravitational potential energy. It is pointless to try to trace back, billions of years, to show how the apple got eight feet up in a tree. To avoid that, the test of a perpetual motion system is performed with careful establishment that the system is closed. In other words, it is contained entirely within a sealed box, perhaps with one outlet which is to be used for the presumed energy transfer.

You had some liquid which was so many feet off the ground. You pour it into a hole in the ground, thus releasing potential energy, by converting it into kinetic energy. If you did not use the kinetic energy at that point, it is lost, by conversion into some less easily usable form of energy, such as heat that diffuses through the Earth.

In one case, however, you contrived the pouring process, to make a sort of a spring, ie., another potential energy situation, by pouring in a lighter fluid, on top of which you put a heavier fluid. Just as with a coiled spring, there is a trigger that will allow the heavier fluid to displace the lighter one. At that point, you could capture some of the kinetic energy, just as you could have with the minature waterfall that occurred when you poured the fluids in.

This is a pretty dull example of perpetual motion "fraud." Interesting ones are welcome.

There IS a maxwell's demon type heater/cooler available commercially. Supply compressed air. amd it blows hot air out of one t pipe end, and cold air out of the other. It's noisy and somewhat inefficient, but the hot air is hot, and the cold air is cold - there can be a 150 degC differential between the two flows.

Brian Whatcott

It is named the "Hilsch Vortex" or "Hilsch Tube."

I have actually used one (as a pedagogical device) when I was a research chemist at the Amarillo helium plant. Very low efficiency, but undeniably effective. Frosts up quickly on a humid day.

Tom Davidson Richmond, VA

Yep. We used them in the Navy as part of damage control. They fit in the back of a steam suit for entering spaces filled with live steam after a steam-line break. Supply the suit with compressed air, and the guy inside is nice and cool. One poor sailor made the mistake of tucking the 'hot end' of the tube inside his suit (supposed to be left hanging out at the waist). Burned his leg when he brushed up against it, that's how hot the 'hot end' got.

daestrom

no one, least of all I the original poster, said it did. I said that Maxy built something on the side. In our imagination. Got an issue with thought experiments?

No, it was a **question** about where the energy came from. I never asserted or implied that there was perpetual motion.

No, it was a **question** that arose from looking at an actual engineered pipeline, and thinking about what goes on inside it.

OK, OK, OK.

Peace.

I said engine.

Yes, it is PM, literally. Solve for zero energy. There is no solution. You are confusing "perpetual motion" with "self-sustenance".

It's not /that/ horrible. And how is one supposed to get a differential acceleration if the generator is foroffkilter?

-Aut

Well, here's a direct quote from the link: "The bad thing about my Coriolis motor..." But that's a moot point.

"Engines" are generally defined as machines that convert heat energy into work (i.e. heat engines), and your machine does not use heat. Your device is really just an energy converter, since all it does is convert the earth's rotational energy into another form.

It does have a solution:

E1 - integral[ Qc(t) dt ]0,t = E2

Where E1 is the rotational kinetic energy of the earth at t=0, E2 is the rotational energy of the earth at t=t, and Qc(t) is the input energy of your coverter as a function of time (which gets its energy from the earth). However, Qc(t) = dE/dt, so you end up with a differential equation with the general solution Ce^-rt, which is the standard decay funtion.

Whatever equation you solved for is not taking into account the FINITE kinetic energy of the earth's rotation. Start your converter, and you'll bleed off the kinetic energy of the earth over trillions/quadrillions of years (depending on the size of your converter).

What equation are you using?

I don't think you understand the true definition of "perpetual motion":

By this definition, your "converter" fails since it's getting its energy from the earth (again, which is a finite source). If you include the earth as part of your machine, it still fails this definition since all you're relying on is an existing, FINITE energy reservoir (i.e. earth).

Dave

I said both, but was pointing out the engine part for this thread.

Engines take differences, such as from a couple, or otherwise convert or transduce energies. Motors move from a single force or energy, like a bike--being over 99% efficient. Then again, they can move from the strongest of many forces. If the observer shares the engine's frame, then it could be a motor.

Since the convertor runs off the very initial and iterative condition of its source, it'll never reach zero.

The definition is not true because it's not literal, and it makes a red herring. Exponents try to rule it out by making it a paradox. Of /course/ work is done /with/ an energy source, even in the case of perpetual motion.

-Aut

I think you're confused. First of all, you've used both "motor" and "engine" to describe your machine, yet provide two separate definitions for each. Which is it? Secondly, engineers and scientists do not use these definitions of engines and motors, so I think you'll find that your the only one that believes your definitions. Lastly, where a "difference" and a "single force/energy" differ is not a clear line to begin with (i.e. is the motor operating of a voltage "source", or a voltage "difference"?). This is really, however, a moot point since it has no bearing on perpetual motion. I'm not sure why you tried to point this out to begin with, especially considering you used both words to describe your device.

By this definition, your converter is unnecessary. All you need is the earth itself. The earth has a "very initial and iterative condition". Why do you even need your machine?

What you've just done is what we used to call "hitting the eject button". You now claim that the mainstream definition of "perpetual motion" is not true, and you've substituted your own definition to fit your needs. Your machine does not fit the mainstream definition of perpetual motion. Your machine is more aptly described as a "constant energy decay" system. This is just like every other physical systems in the entire universe. Welcome to the club.

Dave

It's both, or either. Can you show that they don't share my contrast?

A DC motor usually takes a voltage source, an AC a voltage difference. Do you know what a couple is?

I can't see the earth moving with respect to itself or myself when I'm sitting on it. Coriolis forces are a great way to break inertial frames, not that I believe in inertial frames.

Still, their definition of "perpetual motion" should be applied to "self-sustenence", "self-sustaining motion", etc. instead. Everything in the universe can't have a positive decay of energy either.

-Aut

Omigawd, what pompous, pseudo-erudite buffoonery!

Go ask Alice ...