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Old Jan 1st 2014, 04:30 AM   #1
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E=MC2 and Perpetual Motion

Hello everyone, I am not a physicist and can not make head or tail of the chalkboard equations i've seen physicists create, so if anyone replies to this, could they kindly do so in laymans (leymans?), terms.
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As i understand it, there are 4 laws of thermodynamics, and all of them agree on one thing, namely, perpetual motion is not possible, as anything you make will be less than what it takes to make it in the first place.
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The notion that something is impossible and should therefore never be attempted goes against everything that makes us human, as, like the primates we have evolved from, curiosity is key in driving us forwards.
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80 or so years ago, Albert Einstein was of the opinion that nuclear fission(?) was impossible, as it took more energy to split an atom than could be taken from said split atom, and was quoted as comparing it to shooting birds with a gun, at night, in a country that basically had no birds, or very few birds... yet Leo Szilard proved him wrong.
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Now with concepts like the Bessler wheel for example, i would say that it is improbable, however, in saying that, i would never say impossible, but, and this is an important but, even if someone were to make a variation of Bessler's wheel that did work, it would not be something that energy could ever be harnessed from, as the friction of an added component, like say a dynamo wheel, would grind it to a halt.
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In much the same way, a magnetic system would constantly see north and south polarities fighting each other, and external input would be required to move a driving magnet out of the way of an incoming magnet, before moving it back into place for repulsion and so forth.
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Thing is though, if E=MC2 was deemed impossible to harness prior to Leo Szilard staring at a central London traffic light in 1933, what's to say that a modern day Szilard isn't waiting to cross the road while thinking about perpetual motion?
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The four laws of thermodynamics can not be argued against by someone like myself, granted, but, these four laws were derived about 400 years ago, and in the last 400 or so years, technology has moved on in leaps and bounds, so you can never say never... unless of course you are saying it to advise other people not to say it lol.
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Is perpetual motion impossible, or is it something that is currently outside the reach of our knowledge, because nobody has done like the chicken, and crossed the road?

Last edited by fusedcon; Jan 1st 2014 at 04:33 AM.
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Old Jan 1st 2014, 04:48 AM   #2
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Originally Posted by fusedcon View Post
80 or so years ago, Albert Einstein was of the opinion that nuclear fission(?) was impossible, as it took more energy to split an atom than could be taken from said split atom, and was quoted as comparing it to shooting birds with a gun, at night, in a country that basically had no birds, or very few birds... yet Leo Szilard proved him wrong.
Where did you hear such a thing? That's certainly news to me. You must be refering to natural fission, i.e. a fission that happens all by itself without help from anybody else, correct?
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Originally Posted by fusedcon View Post
Is perpetual motion impossible, or is it something that is currently outside the reach of our knowledge, because nobody has done like the chicken, and crossed the road?
It's impossible in that it violates one of the most well tested laws in physics, the law of conservation of energy. However these are laws which are based on observation. No law can tell you that something you oberved didn't happen. It's just a matter of fact that out of all the interactions we've seen throughout physics it's always consistent with the idea that energy is a conserved quantity. You'd have to be physicist to understand just how imbedded the law of conservation of energy is in nature and how it's always being proved correct on a daily basis in particle accelerator labs across the world, i.e. energy is also conserved on a sub atomic scale.
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Old Jan 1st 2014, 05:03 AM   #3
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Originally Posted by Pmb View Post
Where did you hear such a thing? That's certainly news to me. You must be refering to natural fission, i.e. a fission that happens all by itself without help from anybody else, correct?
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My bad... It was in 1935, and Einstein was asked if he thought that the atom would ever yield its energy.

He said the likelihood of transporting matter into energy is something akin to shooting birds in the dark etc.

He believed at the time, that getting energy out of the atom was not possible or practical... something to do with the amount of energy required to release energy from a single molecule.
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Old Jan 1st 2014, 05:43 AM   #4
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There is a huge difference between saying that some technological advance is impossible versus suggesting that a fundamental physical law (such as the 3rd law of thermodynamics, which is the one that outlaws perpetual motion) can be broken. History is replete with examples of the former that were later proved wrong: skepticism that a heavier-than-air flying machine could ever be built, that nuclear fission could be controlled, that computers could be built small enough to fit unside a desktop size machine. But none of these predictions that something can't be done relied on an argument that to do so would violate a fundamenta physical law - they simply presented an opinion that we won't ever gain the technology to do so. Examples today would include saying that cancer will never be cured, or we will never send a manned space flight to another solar system.

So as for perpetual motion - given what we know today about how the universe works we can say with certainty that perpetual motion is impossible, not because we lack technology but because it would violate the fundamental workings of the universe. Maybe someday in the future someone will discover a "4th law" of thermodynamics that overrides the 3rd, but at least as of today such a notion is fantasy.

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Old Jan 1st 2014, 05:51 AM   #5
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Originally Posted by ChipB View Post
There is a huge difference between saying that some technological advance is impossible versus suggesting that a fundamental physical law (such as the 3rd law of thermodynamics, which is the one that outlaws perpetual motion) can be broken. History is replete with examples of the former that were later proved wrong: skepticism that a heavier-than-air flying machine could ever be built, that nuclear fission could be controlled, that computers could be built small enough to fit unside a desktop size machine. But none of these predictions that something can't be done relied on an argument that to do so would violate a fundamenta physical law - they simply presented an opinion that we won't ever gain the technology to do so. Examples today would include saying that cancer will never be cured, or we will never send a manned space flight to another solar system.
Nicely said, Chip. In fact this was how I was going to respond to this next! I guess it's true what the say, i.e. Great minds think alike. Lol!
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Old Jan 1st 2014, 06:49 AM   #6
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Originally Posted by ChipB View Post
There is a huge difference between saying that some technological advance is impossible versus suggesting that a fundamental physical law (such as the 3rd law of thermodynamics, which is the one that outlaws perpetual motion) can be broken.
So the 3rd law can never be challenged? ever!

OK, well what if perpetual motion is possible without breaking the 3rd law... what then?

And what would the implications of PM be for the inventor / creator of such a device?
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Old Jan 1st 2014, 07:12 AM   #7
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Originally Posted by fusedcon View Post
So the 3rd law can never be challenged? ever!
Only when a new law takes its place such as when a theory is over thrown by a new one. That could happen if someone actually observed the 3rd law being violated in real life, i.e. in the lab or elsewhere in nature. That's what it means to be a law. It's a description of what currently understand what nature is like. However, as I just indicated, that doesn't imply that if a violation of that law which was actually observed didn't really occur. Observation is the root of all science. That means that observation of a violation of the third law does not involve any logical inconsistencies. In fact, not observations can ever be logically inconsistent. This fact was pointed out in the paper Possibility of Faster-Than-Light Particles by G. Feinberg, [I]Physical Review[/b], 159(5), July 25, 1967. This is the paper which coined the term tachyon and came up with the idea of faster than light particles not being inconsistent with special relativity.

Originally Posted by fusedcon View Post
OK, well what if perpetual motion is possible without breaking the 3rd law... what then?
That's a contradiction in terms because perpetual motion is defined as that which breaks the third law. Please don't confuse this with the notion that an object can't move perpetually.

However think more carefully about what you just asked - what if something is possible which is impossible. How do you think a question like that can even be addressed? It can't because it's illogical.

Last edited by Pmb; Jan 1st 2014 at 09:51 AM.
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Old Jan 1st 2014, 10:31 AM   #8
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Originally Posted by Pmb View Post

That's a contradiction in terms because perpetual motion is defined as that which breaks the third law. Please don't confuse this with the notion that an object can't move perpetually.

However think more carefully about what you just asked - what if something is possible which is impossible. How do you think a question like that can even be addressed? It can't because it's illogical.
Hmmm, you're starting to sound like Spock lol.

When i say perpetual motion, i talk of an ability to generate energy rather than something that is constantly moving but capable of doing little else.

And without wishing to antagonise, the question stands as is, mainly because your answer appears to be based on either the 3rd law being unbreakable, or a perpetual motion device not conforming to it.

79 years ago, releasing energy from atoms was deemed impossible due to people not knowing everything, and as you have stated here, should a new law come to pass, the 3rd law becomes redundant, so all things are possible.

Allow me to rephrase the question then... what would happen to a person if they were to create such a device, regardless as to its effects on the 3rd law.
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Old Jan 1st 2014, 10:48 AM   #9
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Originally Posted by fusedcon View Post
79 years ago, releasing energy from atoms was deemed impossible due to people not knowing everything, and as you have stated here, should a new law come to pass, the 3rd law becomes redundant, so all things are possible.
You do realize, don't you, that every scientist has heard all of this before? It seems like countless times I've seen someone say Yeah, well they used to think it was impossible to break the sound barrier too! as if that was the same kind of thing. People used to make those kinds of claims based on there meager understanding of what was possible in practice, not what was stated as a law of nature. It's in that sense that you're confusing what some people thought was possible and not because it was a violation of a law of nature. I know of nobody ever speculating that it was imppssible to release energy from an atom. Nobody knew atoms had that kind of energy stored inside of them. In 1905 Einstein derived the mass-energy equivalence and in that very same paper suggested that energy could be extracted from radium. I.e. Einstein wrote in that paper
It is not impossible that with bodies whose energy-content is variable to a high degree (e.g. radium salts) the theory may be put to the test.
My point is that you have to be very careful about who you've been listening to. Never listen to an engineer when they say something can't be done because they're speaking from an engineering stand point, not a scientific one.

Some people make mistakes when they speculate like that. but that's merely people who were making assumptions based on guesses rather than on the well tested laws of physics. There's a big difference there. A lot of non-scientist no longer trust science because they focused on what non-scientists were guessing and assumed it was scientists making such statements. So please don't blame scientists for all those "[i]It's impossible![/i[ only later to be proven wrong" people.
Originally Posted by fusedcon View Post
Allow me to rephrase the question then... what would happen to a person if they were to create such a device, regardless as to its effects on the 3rd law.
I already addressed this above. If they did so then they'd have proved the 3rd law is wrong.

Now it's my turn to ask you a question - What is regardless as to its effects on the 3rd law. supposed to mean?

A long time ago when I was still in college a friend of mine thought he could make a statement that I'd be stumped on when he said Everything is possible! I mean after all, what could anyone say to that? I think he expected me to disagree wherein he was going to sit back with a smirk and just keep repeating that claim. He didn't expect my response which was Is it possible that you're wrong? Rotl!!

Last edited by Pmb; Jan 1st 2014 at 11:13 AM.
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Old Jan 1st 2014, 11:58 AM   #10
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When i said regardless as to its effects on the 3rd law, it was in response to what you stated; i.e, on the one hand, for it to be so, it would negate the 3rd law and ensure that a 4th law replace it... while on the other hand, also taking on board the fact that the 3rd law can not be broken.

If a person were to create a perpetual motion device that generated energy, what are the implications?

On a personal note, i am neither pro scientists or anti scientists, as stated at the start of this thread, virtually everything that scientists physicists do is above and beyond my comprehension... i'm a bus driver with aspergers and i'm curious about a situation whereby some guys did some thinking 400 years ago and ever since then, their thoughts and opinions can neither be questioned or challenged.

Everything IS INDEED possible, although i would like to ad the footnote... within reason.

But what would happen to such a person IF... they broke the third law and created such a device? after all, you have stated that it could happen, which would mean a new law, but new law aside, what's in it for the creator?

Such a device could cripple energy companies... goodbye national grids, closing down of petrol / oil firms etc.

Communications and internet aside, most of the big hitters in the Forbes list are into energy in one way or another, as literally everyone on the planet needs the stuff.
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