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 AlmightyWalrus wrote:

Guess it's language confusion on my part, but shouldn't a perpetually moving machine be moving, well, perpetually?

Yes, in the same way immortality refers to living 'forever' and vacuum indicates nothingness.

Actually, no. First of all - there is no such thing as immortality, either. Before I get into fantasy, I'd like to point out that perpetual motion, along with everything, is possible or impossible entirely at the discretion of the author of whatever media you happen to be watching/reading/etc. Did you know that 'elf' indicates elves? Oh my!

Immortal beings in fiction are always shown to be just that - immortal. In a similar way to perpetual motion, they will simply last forever. However, for drama's sake, these beings often die or are otherwise destroyed. Elves, for example, are immortal but are susceptible to wounds. It could be stated, then, that the meaning of immortality is similar to that of perpetual motion - an immortal will live forever assuming it is not acted upon by an external force capable of destroying it.

We don't call particularly tough tank armour 'invulnerable', not unless we're adding artistic flair and are being non-scientific. We don't call diamonds that, either. Absolute concepts exist as concepts - indestructibility, infinity, immortality. Many concepts exist that are nothing more than concepts (like perpetual motion, lol).

However what is perpetuity?

Foreverness? How do we sell bonds known as 'perpetuities' on the grounds that they offer ongoing payments ostensibly forever, are we to assume there will always be a stock exchange?
Preserved in perpetuity is a legal term refering to setting up of monuments, particularly parkland again ostensibly forever. Will these parks survive all time?

Perpetuity and perpetual are human terms. In this respect deep space programs can be seen as practical examples of perpetual motion.

This is not to assume absolute.

Legal terms are not physics terms. Physics does not deal with 'good enough'. I mean, come on.

 dogma wrote:

Right, you're now making a faith-based argument.

Big Freeze and Big Crunch are not faith based arguments. Look them up.

 dogma wrote:

 Orlanth wrote:

So are you now going to turn around and say 'its not immortality because you wont live forever'. That would be a joke, we have a concept of immortality which despite the literalist meaning is not absolute.

I like how you're pretending that there is a fixed concept of immortality.

I am pretending nothing, I am instead reasoning. Do we have a concept of immortality without looking at the immortal necessarily transcending all time, except in religion.
The answer is we do. We also have concepts of people who are classifiable as immortal and yet still killable.

You should read the post more carefully I am actually stating that the concept of immortality is not fixed. Yet it has a literal application, amongst others. The concept is perpetual is likewise not fixed, and there are extant uses of perpetual that are definitely not literal. As it can be taken literally and non literally I am applying a non fixed concept of perpetuity as well as immortality.

therefore In terms of real world (or off world) machines a real world (non literal) application is best.

I am pretending nothing, I am instead reasoning. Do we have a concept of immortality without looking at the immortal necessarily transcending all time, except in religion.
The answer is we do. We also have concepts of people who are classifiable as immortal and yet still killable.

You should read the post more carefully I am actually stating that the concept of immortality is not fixed. Yet it has a literal application, amongst others. The concept is perpetual is likewise not fixed, and there are extant uses of perpetual that are definitely not literal. As it can be taken literally and non literally I am applying a non fixed concept of perpetuity as well as immortality.

Well... personally, I've never died. Therefore, I am immortal.

wat

We don't have people who are immortal. We've had leaders who have claimed themselves to be so, and their followers have believed them so because they worshipped them as gods. Are they still alive? No!

I understand what you mean, but you're being ridiculous about it. It's science - terms mean what they mean. There's no "ah, but in the practical sense". We mean words as literally as literal comes.

EDIT: Why does my quote button not work for you? D:

No.

D':

Dr. What wrote:

No.

How about posting a video where they actually watch it long enough for it to stop instead of just a few seconds? I found the "perpetual train" one especially amusing, of course you can get it to roll "uphill"* on the diverging track, but how exactly are you going to keep it moving? Unless your idea of "perpetual" is "reaches the end of my short track" you're going to need to bring the tracks back together, at which point you lose all the energy you gained rolling "uphill" and stop.


*The end points of the cones are rolling uphill, but the center of gravity of the weight is moving downward allowing potential energy to be converted into kinetic energy.

The OP was looking for info on perpetual motion. Though they may not work, they are examples of how it doesn't, thus, they are useful.

How about this?

Dr. What wrote:
The OP was looking for info on perpetual motion. Though they may not work, they are examples of how it doesn't, thus, they are useful.

You've all been great! And yes, the video is helpful. The various patents and so forth would make excellent material to add to the assignment! <3

 Mr Nobody wrote:
How about this?

Lolol, seen this one before. Ununcyclopedia, many years ago...

 Orlanth wrote:
It isn't complicated at all. We have different values of forever, we can take it literally or practicality. Taken literally its a non-issue, end of. Because we cannot fathom a perpetual motion device, or anything else that can survive entropy.
We can however look at this practically. You are confused because you cant see beyond the literal concept to the practical, so let me help you.

No, we take the concept as what it is. Perpetual motion is a comment on entropy. That concept is 'because there is entropy, no system can run forever without an energy input from some other source, and so there cannot be perpetual, self-sustaining motion'.

That's it.

 Orlanth wrote:

The concept is perpetual is likewise not fixed, and there are extant uses of perpetual that are definitely not literal. As it can be taken literally and non literally I am applying a non fixed concept of perpetuity as well as immortality.

So literal is literal when you want it to be literal?

 Frozen Ocean wrote:


Well... personally, I've never died. Therefore, I am immortal.

Nope you and I have a foreseen end, thats mortality.

Got a drug that stops cellular regeneration and then you are 'immortal'.

 Frozen Ocean wrote:

I understand what you mean, but you're being ridiculous about it. It's science - terms mean what they mean. There's no "ah, but in the practical sense". We mean words as literally as literal comes.

Except that we don't. We use non literal versions of the same terms frequently, especially where the literal terms have no meaning. Perpetual motion is a non concept when taken literally because of entropy, entropy will stop a perpetual motion device without having to use friction to do it, therefore the device doesn't have infinite duration therefore it is not perpetual. Consequently we have to look at the wording of perpetual for the concept to remain scientific. Supposed scientific concepts that don't stand up to logic are not scientific concepts. therefore to even discuss perpetual motion you have to take the literal forever out of the equation. Doing so puts us in good company, we can discuss vacuum as a scientific concept, and a practical concept both and neither demands a total absence of material in the volume. We don't get anal over the word vacuum, we can discuss vacuum in a scientific milieu without having to envision a literal vacuum, why should we get anal over the word perpetual.

As for trolling. Trolling is based on lack of manners, not whether one agrees over the content. Disagreeing with you doesn't make one a troll.

 dogma wrote:

 Orlanth wrote:

The concept is perpetual is likewise not fixed, and there are extant uses of perpetual that are definitely not literal. As it can be taken literally and non literally I am applying a non fixed concept of perpetuity as well as immortality.

So literal is literal when you want it to be literal?

Yes indeed, but not as you imply personally by me alone on a whim.
I have given plenty of examples when concepts that can be taken literally and non literally both are take one way or the other by people in the scientific and non scientific fields alike.
Where the literal definition has no meaning or no value a non literal version is preferred and used.

 Orlanth wrote:
Perpetual motion is a non concept when taken literally because of entropy, entropy will stop a perpetual motion device without having to use friction to do it, therefore the device doesn't have infinite duration therefore it is not perpetual.

Except we HAVE defined "perpetual" in other terms. A perpetual motion machine is a machine which operates without losing energy or drawing energy from outside the machine. It's called a "perpetual" motion machine because, in the absence of damage to the machine or any other kind of disturbance, it will run forever. The eventual end of the universe is "damage to the machine", so it doesn't count.

By that definition, the deep space probe is NOT a perpetual motion machine because it is slowly losing energy due to friction. Even if the universe ends (or the probe crashes into a star) before its kinetic energy reaches zero it is still declining in perfect obedience to the laws of physics.

 Orlanth wrote:
Except that we don't. We use non literal versions of the same terms frequently, especially where the literal terms have no meaning. Perpetual motion is a non concept when taken literally because of entropy, entropy will stop a perpetual motion device without having to use friction to do it, therefore the device doesn't have infinite duration therefore it is not perpetual.

You realise at this point your argument is 'when perpetual motion uses the actual meaning of perpetual then perpetual motion can't exist, therefore it is best to use some other meaning for perpetual'.

Dude, you posted a picture of a satellite and said it was something it was not. That's all. It's okay. No need for all this nonsense that's followed.

 Peregrine wrote:

 Orlanth wrote:
Perpetual motion is a non concept when taken literally because of entropy, entropy will stop a perpetual motion device without having to use friction to do it, therefore the device doesn't have infinite duration therefore it is not perpetual.

Except we HAVE defined "perpetual" in other terms. A perpetual motion machine is a machine which operates without losing energy or drawing energy from outside the machine. It's called a "perpetual" motion machine because, in the absence of damage to the machine or any other kind of disturbance, it will run forever. The eventual end of the universe is "damage to the machine", so it doesn't count.

By that definition, the deep space probe is NOT a perpetual motion machine because it is slowly losing energy due to friction. Even if the universe ends (or the probe crashes into a star) before its kinetic energy reaches zero it is still declining in perfect obedience to the laws of physics.

Then explain why we have vacuum experiments without vacuum.
Shouldn't they be called something else, like ultra low density pressure or some such. No, we use 'vacuum', its a perfectly good word even though its a literal scientific description.
Sometimes close is good enough.




Automatically Appended Next Post:

 sebster wrote:

You realise at this point your argument is 'when perpetual motion uses the actual meaning of perpetual then perpetual motion can't exist, therefore it is best to use some other meaning for perpetual'.

A point, not the only point. And guess what, we do.
Many things are listed as 'perpetual' that are not literally so. I gave examples in previous posts.

This thread is about the scientific idea of perpetual motion.

We have so-called vacuum experiments because it is possible to achieve a vacuum good enough for experimental purposes, and scientists describe them as such.

That doesn't validate the use of "perpetual motion" for a machine that only runs down very slowly, when the scientific definition of perpetual motion is a machine that doesn't run down at all.

If you take words and apply them differently to the way that scientists use them, it isn't surprising that you come up with different meanings.

 Orlanth wrote:

Where the literal definition has no meaning or no value a non literal version is preferred and used.

No, that's wrong. You don't reevaluate terms simply because the concepts to which they're associated have been proven to be erroneous.

We don't use "phlogiston" in any serious context other than where the literal meaning of the term is important.

Words, definitions, employment of said.

 Orlanth wrote:

Then explain why we have vacuum experiments without vacuum.

That is why we use the term "perfect vacuum".

You're being deliberately obtuse now.

Flat Earthism is being exhibited here. You are trolling.

 Kilkrazy wrote:

If you take words and apply them differently to the way that scientists use them, it isn't surprising that you come up with different meanings.

You are assuming there is a standard set definition of perpetual motion where in fact there isn't. It has multiple definitions and multiple classifications.
http://en.wikipedia.org/wiki/Perpetual_motion

Why not add one more, for real life objects which appear to have the characteristics of perpetual motion within a human societal timeframe. If the deep space probes will still run when we are extinct why not add that as a form of practical perpetual motion in the same way that a near vacuum is considered good enough to be considered vacuum.

 dogma wrote:

Flat Earthism is being exhibited here. You are trolling.

You tell me how is this Flat Earthism and I will tell you why its not trolling.

Trolling is about ill manners and deliberate personal offense not disagreement over content. I don't troll Dakka, I like to argue on the issues respectfully and without resorting to namecalling. It would be nice if you tried the same.

Flat Earthers believe that deep space probes are lies anyway, so it would be odd indeed for my argument to be Flat Earthism.

 Orlanth wrote:
Why not add one more, for real life objects which appear to have the characteristics of perpetual motion within a human societal timeframe. If the deep space probes will still run when we are extinct why not add that as a form of practical perpetual motion in the same way that a near vacuum is considered good enough to be considered vacuum.

Because it's not a useful definition.

The concept of a "perpetual motion machine" inherently includes the idea that it's a new discovery that does something previously thought impossible. Broadening the concept to include things everyone agrees are possible completely contradicts that part of the definition. You can make your special definition of "perpetual motion machine", but you're no longer saying anything useful with it, and there's no reason to make the change except that you want to win a forum argument.

You tell me how is this Flat Earthism and I will tell you why its not trolling.

The point is you're taking an obvious devil's advocate position on a stupid subject and defending it to the death by re-defining terms to suit yourself. Just like 99% of flat earth "believers" are just doing it to see if they can win a forum argument.

 Orlanth wrote:
A point, not the only point. And guess what, we do.
Many things are listed as 'perpetual' that are not literally so. I gave examples in previous posts.

Lots of words have lots of different meanings in different contexts, but when you have specific context you use that meaning.

In this context the meaning of the word 'perpetual' is well known, well understood, and effectively explains a key scientific principle about entropy.

 Orlanth wrote:

You tell me how is this Flat Earthism and I will tell you why its not trolling.

You are clearly and purposefully misusing words and concepts in order force into existence a definition of perpetual motion that is consistent with the laws of physics. You are doing this only because you want the phrase "perpetual motion" to be a useful descriptor with respect to reality*. Flat Earthers, in a very similar way, attempt to revise terminology so that the Earth can be correctly referred to as flat. The distinction between you and them is that they do this as a matter of sport within a group of people that understand what they're doing as sport.


*Or you're trolling, which is a more flattering behavior.

 Orlanth wrote:

Trolling is about ill manners and deliberate personal offense not disagreement over content. I don't troll Dakka, I like to argue on the issues respectfully and without resorting to namecalling. It would be nice if you tried the same.

No, trolling is an attempt to elicit a particular response from someone else by being disingenuous. Making a deliberately ridiculous argument in order to annoy people is trolling.

Simply being insulting is not trolling.

 Orlanth wrote:

Flat Earthers believe that deep space probes are lies anyway, so it would be odd indeed for my argument to be Flat Earthism.

The method of argument you are employing is essentially the same one employed by Flat Earth members, many of whom do not actually believe the premises they begin with but instead argue for the enjoyment of argument. Another descriptive term for this behavior would be "sophism".

 dogma wrote:

 Orlanth wrote:

You tell me how is this Flat Earthism and I will tell you why its not trolling.

You are clearly and purposefully misusing words and concepts in order force into existence a definition of perpetual motion that is consistent with the laws of physics. You are doing this only because you want the phrase "perpetual motion" to be a useful descriptor with respect to reality*. Flat Earthers, in a very similar way, attempt to revise terminology so that the Earth can be correctly referred to as flat. The distinction between you and them is that they do this as a matter of sport within a group of people that understand what they're doing as sport.

Redefining concepts so that they make sense within the laws of physics and are useful is a laudable goal. We do this all the time its part of how language evolves.
Flat Earther's methodology is a denial of evidence under the mantle of conspiracy and manufactured counter-evidence.

 dogma wrote:

No, trolling is an attempt to elicit a particular response from someone else by being disingenuous. Making a deliberately ridiculous argument in order to annoy people is trolling.

Except that my argument is not deliberately ridiculous, its to make a turn an extant nonsense definition and reuse it in a manner that makes sense. We do this before with 'vacuum' and 'immortality', I am doing so here.
Were I to flatly deny the friction drag effects of deep space in contradiction of the evidence that might be annoying, but I dont do so. Even you admitted that I was trying to make good use of a term that has no scientific value under its prior meaning.

 dogma wrote:

Simply being insulting is not trolling.

Manners is everything, it's all we have here.

 Orlanth wrote:

Flat Earthers believe that deep space probes are lies anyway, so it would be odd indeed for my argument to be Flat Earthism.

The method of argument you are employing is essentially the same one employed by Flat Earth members, many of whom do not actually believe the premises they begin with but instead argue for the enjoyment of argument. Another descriptive term for this behavior would be "sophism".

 Orlanth wrote:
Redefining concepts so that they make sense within the laws of physics and are useful is a laudable goal. We do this all the time its part of how language evolves.

Except the current definition works just fine. It refers to a class of inventions which make a specific claim, but don't work for a specific reason. The fact that it's primarily used to describe how something fails does not change the fact that it's a very useful concept with a clear definition.

All your change does is remove all meaning from the term by applying it to an entirely different class of objects, for the sole purpose of being able to apply the term more broadly. It's like saying we should broaden the term "white" to include "dark gray" because it would include more things.

Except that my argument is not deliberately ridiculous, its to make a turn an extant nonsense definition and reuse it in a manner that makes sense. We do this before with 'vacuum' and 'immortality', I am doing so here.

Except we didn't do it with those terms. Immortality still has the exact same definition (you will live forever until something external kills you, whether that "something" is a gun or the end of the universe), and vacuum only has a "different" meaning because it's easier to just say "vacuum" instead of "almost vacuum but close enough for this purpose". Everyone still understands that it's not true vacuum, and nobody would ever argue that a true vacuum is possible because we used a 'vacuum' for an experiment.

You could catch anyone here on that. Why do we have these discussions but because we enjoy being here.

Because we actually believe the points we're arguing?

Your argument seems exactly like flat earthism in that you only care about winning the forum argument, no matter how many terms you have to redefine for the sole purpose of winning.

I redefined one term, the others were already redefined, or more accurately softened for use.

Were space probes hypothetical then there would be no excuse to soften the terms, but as they are real objects moving at with no appreciable deceleration compared to the lifespan of our species.
You choose to accept practical vacuum, and practical immortality as terms but not practical perpetual motion. Fine, fair enough, but it's an arbitrary distinction as a precedent has been made.

My argument differs from Flat Earthism on a number of ways. Flat Earthism is about a culture of scientific denial, I am not denying physics. As for wishing to win the argument, you can throw this back at yourself also, is it not why you reply. I have a reason to stand my ground though. It was not only my premise that was under attack but my personality by comments many of which were intended to denigrate the person not the argument. That is not acceptable behaviour, but in addition as I actually have a rational argument, just one that you don't agree with, I consider it best to reiterate it so that it is seen in fair light.. Others such as yourself have argued your point of view in a more acceptable manner, rather than responding with insults and accusations. Your input is welcome and respectfully received.

 Orlanth wrote:
Were space probes hypothetical then there would be no excuse to soften the terms, but as they are real objects moving at with no appreciable deceleration compared to the lifespan of our species.

Except we have a perfectly good way of describing those space probes, and have no need to redefine "perpetual motion machine" to include them.

You choose to accept practical vacuum, and practical immortality as terms but not practical perpetual motion. Fine, fair enough, but its an arbitrary distinction.

No I didn't. Try looking more carefully at who you're talking to when you post?

Note, was adding to old post while your replied.

 Peregrine wrote:

You choose to accept practical vacuum, and practical immortality as terms but not practical perpetual motion. Fine, fair enough, but its an arbitrary distinction.

No I didn't. Try looking more carefully at who you're talking to when you post?

I was replying directly to your post. You accept practical vacuum:

because it's easier to just say "vacuum" instead of "almost vacuum but close enough for this purpose".

Thus to take an absolute concept and turn it into a practical achievable one in a scientific milieu.
Thus the precedent has been set to take unachievable absolute values and redefine them to fit accomplishable goals. This is a flat fact.

The decision to accept a loosening of other absolute scientific terms is arbitrary. You choose to reject a softening of perpetual motion, I do not on the grounds that were have a material example of a something 'close enough for this purpose'.
I am not saying your wrong, it isn't a right or wrong issue, it's a semantic issue, like the softening of the word vacuum is a cultural choice not a scintific one, but one accepted as covering various scientific realities based on whether a valuie is close enough to the absolute value for human observation or utility. Deep space probes have a similar dynamic, after a fashion they touch the eternal in a way absent from anything else but mathematics and religion.
Hence my call for a practical definition.

 Orlanth wrote:
I was replying directly to your post. You accept practical vacuum:

because it's easier to just say "vacuum" instead of "almost vacuum but close enough for this purpose".

Thus to take an absolute concept and turn it into a practical achievable one in a scientific milieu.
Thus the precedent has been set to take unachievable absolute values and redefine them to fit accomplishable goals. This is a flat fact.

Oh FFS. Why is this so hard for you?

1) There is absolutely no changing of the term to redefine an unachievable absolute into an accomplishable goal. All scientists are doing with 'vacuum' is recognizing the obvious fact that it's easier to say 'vacuum' instead of 'almost a vacuum but not really, but still close enough for this purpose' when you have to refer to the concept a hundred times in a paper. Everyone knows that they're really saying the latter, they just say it with fewer words. If it makes it easier for you, think of 'vacuum' as really being two words: 'vacuum' and 'v4cuum', except written with a keyboard with no '4' key and scientists are smart enough to recognize which is which.

2) No scientist would ever claim that a true vacuum is possible based on that "redefinition", while you are redefining "perpetual" for the sake of making perpetual motion machines "possible".

The decision to accept a loosening of other absolute scientific terms is arbitrary. You choose to reject a softening of perpetual motion, I do not on the grounds that were have a material example of a something 'close enough for this purpose'.

Except there is no "close enough" in this case.

A perpetual motion machine is impossible because it claims to ignore (or worse, reverse) friction/entropy/etc. It isn't close enough to put a probe into an area where those factors are low because it's operating under entirely different physical principles from a true perpetual motion machine. The probe does not in any way ignore friction, it merely experiences very little of it.


Here's an analogy for you: psychic levitation is impossible. However, I can jump, which is "close enough" to levitation. Should we now say that levitation is possible?

 Peregrine wrote:


Oh FFS. Why is this so hard for you?

It isn't hard, I understand the second law of thermodynamics.

 Peregrine wrote:

1) There is absolutely no changing of the term to redefine an unachievable absolute into an accomplishable goal. All scientists are doing with 'vacuum' is recognizing the obvious fact that it's easier to say 'vacuum' instead of 'almost a vacuum but not really, but still close enough for this purpose' when you have to refer to the concept a hundred times in a paper. Everyone knows that they're really saying the latter, they just say it with fewer words.

2) No scientist would ever claim that a true vacuum is possible based on that "redefinition", while you are redefining "perpetual" for the sake of making perpetual motion machines "possible".

1. The term changes because the term changes.
2. I am on the same seat as the scientist who understands the word 'vacuum' doesn't mean literal vacuum. I am not advocating that practical perpetual motion is literal perpetual motion.

 Peregrine wrote:

Except there is no "close enough" in this case.

Actually 'close enough' is what we count on.
we rely on close enough vacuum to work a laser in an experiment.
We rely on close enough perpetual motion for the deep space probes.

On an engineering level when a factor is negligible its ignored. A physicist may not like calling the vacuum tube a vacuum tube at first, but on an enginerringing level its a vacuum.
Space probes are close enough in this case, they had one large input of kinetic energy in the 1970's, yet they are still moving, and are projected to still be moving long after we are extinct. Why is that so hard for you?

Here's an analogy for you: psychic levitation is impossible. However, I can jump, which is "close enough" to levitation. Should we now say that levitation is possible?

Only if you sustain the jump, then it would be 'close enough' to be levitation.

 Orlanth wrote:
1. The term changes because the term changes.

Except the term ISN'T changing. Like I said, think of it as two separate terms that just happen to be represented using the same letters, and scientists are smart enough to know which is which from context.

2. I am on the same seat as the scientist who understands the word 'vacuum' doesn't mean literal vacuum. I am not advocating that practical perpetual motion is literal perpetual motion.

Then that makes it even more pointless. If were doing that you'd be wrong, but at least you'd have a goal. All you're actually doing then is expanding "perpetual" to cover something new just for the sake of making "perpetual" cover more things.

Actually 'close enough' is what we count on.

Read again, I didn't say we never use 'close enough', I said this isn't a case of 'close enough'.

A perpetual motion machine claims to generate energy out of nothing to offset friction losses (since the endless varieties of 'spinny wheel with extra bits on it' don't claim to have a frictionless wheel) and maintain (or, worse, increase) its energy state.

An object moving in a near-vacuum does NOT create energy out of nothing, does not maintain its energy state, and is not a perpetual motion machine.

They are two entirely different concepts, and the only purpose in combining them is to make "perpetual" cover more things.

Only if you sustain the jump, then it would be 'close enough' to be levitation.

But I sustained it for long enough. And since 'levitation' is a useless term that can't be achieved we should redefine it to include something achievable, right?

"Practical" perpetual motion involves an engine that can be used to do work without an energy input.

That's what the term means to a scientist or engineer.