Perpetual Motion - is it so damn hard?

I know nothing about your personal problems.

Capillary, eh? Already been tried. Already failed - the force that pulls the water up the tube prevents it leaving the tube at the top…

The problem with all these ideas for varying boyuancy is that you can’t just vary your bouyancy by creating gas. Yes, you can create hydrogen and oxygen by splitting water via electrolysis. But creating those gasses won’t increase the bouyancy of the system.

Suppose you’ve got a submarine. In the submarine is a tub of water. You run a current through the water and create H2 and O2. The gases mix with the air in the submarine. Does the submarine rise? No it does not, because the total volume of the submarine has not changed, and the total mass of the submarine has not changed. All that happened is that the air in the submarine got denser.

The only way to make the submarine rise is to either decrease the mass of the submarine, or change the volume of the submarine. So if you had bladders attached to the submarine, with water inside, and split the water, and the bladders filled with H2 and O2, the submarine would rise, because you increased the volume of of the submarine without changing the mass of the submarine, thus decreasing the density.

But the water around the submarine is pushing against the bladders. It requires energy to inflate the bladders, they don’t magically inflate just because you changed the state of the matter inside the bladders. You can easily see why this is so if you imagine that instead of creating H2 and O2, you decided to create gaseous H20. You use your electric circuit to boil water and turn it into steam, and vent the steam into the bladders. Your submarine will rise. But you didn’t get that bouyancy for free, you had to boil the water. The same thing happens when you split the water via electrolysis. You have to add enough energy to lift all the water above the submarine.

And this is where perpetual motion machine inventors get caught. They think that bouyancy, or magnets, or whatever, don’t require energy. But it turns out that they do.

If you play with a couple of powerful magnets, it’s really quite easy to come away with the impression that they are capable of doing work - I think it’s a combination of the spooky invisible action (gravity is similarly spooky, but we can’t play with it so easily) and the force gradient - the way they suddenly snap together seems like it’s something that could be exploited again and again.

But the problem with magnets (and perpetual motion attempts in general) is that gravity, buoyancy, magnetism, all cannot be reversed more cheaply than they act forwards. You can’t roll a ball down a valley and expect it to rise higher up the other side.

No it isn’t damm hard!

You need to learn your physics thoroughly to learn that it is absolutely well nigh impossible!

WHEN and IF you succeed in producing more enery than your process produces you will be quite wealthy IF the Men In Black don’t do you in or spirit you and your invention of to join Jimmy Hoffa.

Regarding the laws of thermodynamics, the old physics joke goes:

  1. You can’t win the game.

  2. You can’t break even.

  3. You can never quit.

The universe as we know it is a closed system, and it’s very existence is made possible by things like the laws of thermodynamics and the conservation of energy and momentum. The fact that the universe exists and behaves the way it does unequivocally demonstrates that these physical laws don’t go away when we aren’t looking (or just because we want them too.)

A true “perpetual motion” machine can only work if it imparts no energy to its surroundings. If such a machine is in fact producing more energy than what is being put into it, it will inevitably lose mass and disappear altogether.

In short, if you want to make it work you’ll have to find another universe. It isn’t going to work in this one.

I think someday we will find the so-called “laws” of thermodynamics were only suggestions. Radio, telephones, television, fast trains, airplanes, nuclear power, space flight, and the moon landing were all once declared impossible.

As we learn more about the universe I have faith that one day we will break these “laws” without penalty and energy will flow freely as a result.

i think claims of those not being possible was based on technology limitations on the part of the claimant due to engineering as far as they knew it. where claims made not based on engineering?

laws of thermodynamics is science which is a different view. both natural and man made phenomena have been examined to lead to those beliefs.

There are predictions of impossible, and then there are observations on the nature of the universe.

“No flying machine will ever fly from New York to Paris … [because] no known motor can run at the requisite speed for four days without stopping.” ~ Orville Wright ~

This is Orville incorrectly defining the problem.

Where can I get the energy to overcome all entropy? hmm. I can wait until the end of time, and hope that it reverses.

Tris

Today’s science is tomorrow’s scripture.

Not for anything like the same reasons as the laws of thermodynamics are asserted. In fact, if the laws of thermodynamics are overturned, we’ve got to find brand new explanations for why some of the things you listed even work.

What you’ve done here is to make a false analogy, but that argument can be used to support any and everything - for example: Walking through walls is now considered impossible, but we will be able to do it, because once, we thought heavier-than-air flight was considered impossible for humans, but now we can do it.

I already sort of promised to be quiet here, but I now try to explain why I even bothered to start these you may say “already doomed” themes.
There are several Laws of Physics stating lots of facts on whatsoever. If the laws cannot explain how this ultimate perpetual motion machine - the macrocosm - works, how precise can they be. Shouldn’t you at least have to know the end of this motion, where it ends and so on. There is similar lack of knowledge concerning the microcosm. So in order to come up with something new, we may assume ie. that microcosm starts where macrocosm ends and vice versa. The Laws of Physics must bend somewhere in this philosophy (Yin and yang).

Plus I’m just a beginner in Physics.

So, I came up with a new idea. What if the ‘subvelin’ went through a mile long induction coil. Now there’s a lot more energy involved to produce rocket-gas.

The bottom line here is you can’t get more energy OUT of a system than you put IN. It’s seductive to think that if you just add another component or tweak the system in some way that voila! you’re now getting out more than is put in.

Not true. Never true.

The additional components more serve to obfuscate where the energy goes–you accidentally forget to account for an energy loss, and now the system looks more tan 100% efficient.

To examine a perpetual motion machine, try looking at the energy. For a full cycle of your machine, where does the energy, come from, where is it stored, and where does it go? Actual calculations will show that you’re not getting more out than you put in, but even without calculation, a full accounting of how the energy is converted from one form to another will probably show more losses than you think there are.

If I build a solar powered tap-dancing robot and place it where the planet gets most sunshine, wouldn’t that be a “perpetual motion machine” by the standards that are relevant to our feeble life spans? It wouldn’t need to last for eternity, just long enough for us to survive without using fossil fuels.

The relevant question is: would even a single water molecule have its position shifted as a result of the subvelin’s passage? If so, your scheme is doomed - it takes energy to move molecules, energy that will thus not be available to generate gas or do any of the other things that might keep the system functioning.

The definition of a “perpetual motion machine,” as a term of art, is a device that, once set in motion, would continue in motion forever, with no additional energy required to maintain it. (See Brittanica, frex). Some confusion arises (see the discussion upthread) because “perpetual” and “motion,” taken singly, don’t carry the implication of lack of energy input that the term of art requires.

So the solar-powered robot is an “unceasing movement device,” but because it receives additional energy, it’s not a “perpetual motion machine.”

If the laws of science don’t provide a total explanation for something doesn’t mean the laws aren’t true. Gravity was known and people used it predictably and developed laws about it before its causes. Laws are observations not explanations. Explanations can result from observations and study.

For all practical purposes (the likely existence of humans and in our solar system) we have a perpetual motion machine and it is our atmosphere, as long as the sun shines and the earth has a gaseous envelope with land and water below it then it will run and collect and store heat and light and produce motion.

Nobody is trying to get you to be quiet - I want to be really clear about that.

  • It may seem like we’re all trying to shout you down, but really, that would be a terrible shame. These discussions are interesting - and I’ve learned a few things in this last couple of threads too. I think I can speak on behalf of the majority here in saying: please feel free to keep asking questions.

That energy still has to come from somewhere - There is a limit to the amount of energy that you can extract from an object in motion - when you approach that limit, the object slows down (because the energy IS the motion. When you extract all the kinetic energy from an object, it stops moving.

You can’t get more out than is in there - so for example a ball can’t bounce higher than it is dropped.

You can’t get out more than is accumulated - so if you catch the ball at the bottom of its drop and harvest the energy of its motion, it cannot exceed the amount of energy it acquired while falling - which will not be enough to throw it higher than it fell from.

You can only get more out than you put in if there was already some in there before you arrived - so for example you can burn a piece of coal, but only once - then you’ve taken the previously stored energy out.

as mentioned it is not a perpetual motion machine in the sense of physics.

it could be a long term motion machine. when the solar collection mechanism died or the moving parts became stuck due to friction (lubrication and bearings don’t last forever) it would stop.

a Crookes radiometer will run with light shining on it and could run for centuries.

wind turbines with maintenance, renewal of parts and downtime could run for centuries.

there is a watch that is wound by barometric pressure that has run for a long time.