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Topic Title: What is Energy?
Topic Summary: Is Energy a real and definite "thing"? or is it a conceptual and relative notion?
Created On: 14 March 2013 04:19 PM
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 16 April 2013 09:11 PM
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westonpa

Posts: 1771
Joined: 10 October 2007

Originally posted by: jarathoon
They are attracted into saying more and more things about black holes that no observational astronomer is ever going to be able to verify.

Yes, because they can seem to be extremely clever without having to prove it. There is enough here on Earth and local to our solar system, and which we have a possibility to go and check, that we can learn about. When we know those things then I think we will be ready to move further out.

Regards.
 16 April 2013 10:59 PM
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kengreen

Posts: 400
Joined: 15 April 2013

Gentlemen ... and, I hope, Ladies,

I joined this Forum in the hope that I might meet people who can, and wish to, think, I fear that it is a talent sadly missing in today's scientific community.

We might well start modern Physics with the creation of the Expanding Universe ... into what is it expanding ?

In the previous Posts there has been some play with Natural Laws which I take to mean certain Rules which Man has deduced from observation. BUT mathematics (a home-brew) has man-imposed Rules of its own which can be simplified as:
(i) Insert ALL information and in the correct order
(ii) apply procedures according to the Rules under which they were formulated
(iii) Interpret the results to make them understandable in an appropriate language


My introduction to Relativity put forth the wisdom that Einstein proposed that Gravity had two components:
(a) a force of mutual-attraction which varied inversely with distance according to an inverse-square law
(b) a force of mutual-repulsion which varied inversely with distance according to a linear law.
Mix well and apply a soupcon of alcohol and everybody starts looking for a DOPPLER red-shift - AND they found it.

Enter a little-known Astronomer called Hubble and he went the way of the reverse engineer ... he first discovered a red-***** which apparently was proportional to distance and so invented an Expanding Universe.
Correct me if I am wrong but is not a space - vehicle named Cassini (?) now on its way into deep Space but is willfully wandering "off course" ? A great demonstration that mathematics derived on the limited confines of planet Earth will not necessarily apply in the vastness of Space.

I must stop here because my one eye is raising objections but, should anyone want a fight or is curious, I can oblige. Think some about that Doppler effect ?

Ken Green

Ken Green
rth
 17 April 2013 01:29 AM
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jarathoon

Posts: 1040
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CliveS

We can think of energy as quantitative measure, but also qualitatively as a concept. Energy is something we can measure for billing purposes, but energy is also something that appears to be real and which can be thought about as if it were a substance, much like we thing of an "atom" as something real with various associated properties.

We should perhaps have two different words for these two different aspects.

Qualitative meanings gradually shift over time as we learn more about the world. What we mean by the word "atom" is quite different to what Dalton meant by the word "atom" for example.

Originally posted by: acsinuk

Energy is movement and can be measured in joules or Watt-seconds. A more practical unit is 3,600,000 times bigger and called a kWh.


You have put energy the qualitative concept into the same sentence as energy the quantitative concept.

Energy (storage) does not necessarily imply movement. Potential energy (e.g. Gravitational Potential Energy) can be defined in ways which avoids the concept of movement. However I have no way of ruling out the possibility that energy, the real substance, is synonymous with movement. Many people would agree with you that energy is synonymous with movement, but I don't think we know enough to be certain on this.

Originally posted by: acsinuk

We imagine that it is a scalar quantity but in its not, as it must be contained in a volume of something which we can measure the temperature of. Energy should be measured practically in kWh per cubic metre.


Energy is a scalar quanity in its quantitative definition.

kWh per cubic metre is a measure of energy density.

Energy density is a very important concept in its own right (and may be viewed as the primary concept as you suggest), however energy density it is not the same as energy.

Energy in it qualitative sense is a concept, so I agree, when used in this sense it is not a scalar; it is noun or label for our knowledge of it, and some of this knowledge still remains vague and ill defined. Indeed theories in different domains of physics and engineering say inconsistent things about it.

Originally posted by: acsinuk

It is then easier to visualize how if you continue to add energy to a set volume that the PV=RT law will increase the gas temperature and how the other laws for temperature rise in solids and liquids of classical physics will apply.



the PV=RT law is the perfect gas law and is not in general true. There is no thermodynamic law which states we have to define temperature on a linear scale. I believe it is just an engineering convention.

James Arathoon

-------------------------
James Arathoon
 17 April 2013 05:57 PM
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acsinuk

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James
Thanks for your reply which illustrates how easy it is to get mixed up with the semantics.
Your statement "kWh per cubic metre is a measure of energy density." is correct but the mention of density immediately makes one think of mass which must be avoided as matter in my view is only a time tied state of fundamental 3D electromagnetic magnoflux energy.
Electromagnetic energy or light is of course massless but it does occupy a set volume of space. So when I see that Planck's constant is 6.6x10^-34; what this means to me is that there are the reciprocal number of 1.62x10^33 photons in one cubic metre of space which would then contain one joule quantity of energy for each pulse per second. At 50 cycle there will be 50 times as many photons moving through the spare space holes around the outside of a conductor.
Our system of dimensions which defines this basic fundamental indestructible energy unit as some secondary unit of ML^2/T^2 just confuses me!
CliveS
 17 April 2013 08:40 PM
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kengreen

Posts: 400
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The greatest ... the most vexing ... question for me involves the complexities in the Mind(s) of the genii who construct Web-pages. I am a V.I.P . of the ignominious type (a visually-impaired person) and I am wandering around in a set of over-stocked pages wherein I cannot find the meaning for the words.

But enough ! This matter of so-called Energy has consumed my spare moments for over 55 years and allow me to tell you that it does NOT exist.

DEFINITION
Energy is a commodity that causes a Body to perform Work, at some time in the Future, if and when it suffers an acceleration

Here i use acceleration in its Mathematical incarnation ; i.e. a change in either/or speed and direction.

(1) Do you consider that to be rigorous ?
2. Does it describe kinetic energy or static energy?
Let's see if I cxa POST this ?

Ken Green
 18 April 2013 03:23 AM
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jarathoon

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Originally posted by: kengreen

But enough ! This matter of so-called Energy has consumed my spare moments for over 55 years and allow me to tell you that it does NOT exist.



Certainly your spare moments no longer exist. We all seem to lose those without hardly trying.

Imperfect philosophical observations continued...

Mach, Einstein and others tried to eliminate the concept of Force as a fundamental notion from physics. I have in the last few years become more and more attracted by this research programme, because it seems to me like it might be possible to progress it some more. I sometimes think it might even prove necessary to follow this path to reach the "truest", yet at the same time most abstract reflection of reality that we will ever attain.

However, don't worry, as soon as we want to make theoretical or engineering predictions about the real world that need to be compared with our measurements and experience of it, we must reconstruct, via a consistent calculus, the familiar mathematical relations between energy and force. Force is reinvented as a sort of imaginative necessity.

So it is perfectly feasible to accept that "force" is not necessary for an unobserved universe to function independently of us, yet at the same time admit that the concept of force is a necessary and efficient tool to describe and improve our understanding of the dynamics of our newly observed universe.

Since denying the fundamental reality of both force and energy gets you precisely nowhere in the field of engineering, I have to assume that you take the opposite view to Mach and Einstein, and consider the concept of force to be the more fundamental one and energy the derivative one.

I personally prefer denying the independent reality of force as this leads to a much more pleasant and interesting conceptual framework for me, than I could ever get to by denying the independent reality of energy.

Originally posted by: kengreen


DEFINITION

Energy is a commodity that causes a Body to perform Work, at some time in the Future, if and when it suffers an acceleration

Here i use acceleration in its Mathematical incarnation ; i.e. a change in either/or speed and direction.

(1) Do you consider that to be rigorous ?

2. Does it describe kinetic energy or static energy?



"(1) Do you consider that to be rigorous ?"

No your definition is definitely not rigourous - and neither is... Heat is not the same as work, yet both heat and work are forms of energy. All work can be transformed into heat, yet not all heat can be transformed into work. Asymmetries abound, and bodies rebound.

In your opinion energy does not exist, which begs the question: What is the purpose of trying to create a rigorous definition for something that you don't believe exists?

In my opinion energy is real (and our knowledge of it vague and imperfect); so I believe energy exists independently of whether or not, or how, we choose to "commoditise" it. Hence your definition appears nonsense to me.

"2. Does it describe kinetic energy or static energy?"

More kinetic than static, but neither convincingly or rigorously.

Acceleration has at least two mathematical incarnations, either as a scalar (hydrostatic pressure type scalar acceleration ina ll directions outward at the same time) or a vector as you describe. The concept of energy encompasses scalar forms of acceleration as well as the vector.

James Arathoon

-------------------------
James Arathoon
 19 April 2013 07:17 AM
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kengreen

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I have been reading through the Posts that precede my presence among this community which are attempting to respond to the question:"What is Energy?" There are many words there but, if you will forgive, no one has truly tried to answer the question ?

I posted my favourite definition but James dismissed it summarily as "Not rigorous"; OK James but surely you owe me, and all involved in the Forum, at least one reason? My second question: "Does it apply to static (potential) energy or to the dynamic sort was in truth given much the same treatment. I bring this up not to criticise James but to illuminate my contention that words are too cheap and spill too easily from the tongue.

James mentioned his dissatisfaction with the accepted wisdom that the Earth's magnetic field arises from its having a molten iron core that sloshes around as the Earth spins? I agree. My instruction and experience in both electric and electronic theory form a tight association between magnetism , electricity and relative-motion. While I can dream up a few scenarios I have yet to come across an explanation that even attempts to make sense. "Better not in case I make a fool of myself" ?

Man or Mouse ? :-)
 19 April 2013 01:30 PM
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jarathoon

Posts: 1040
Joined: 05 September 2004

Originally posted by: rogerbryant

I would recomend reading 'The Trouble with Physics' by Lee Smolin if you haven't already done so. He and Roger Penrose, 'The Emperors New Mind' both consider we are missing some very important point or points in our understanding of physics.


Thanks I read both books some time ago.

Lee Smolin has written an article in this weeks New Scientist on the nature of time "It's time to rewrite time", to publicise his latest book to be published later this month "Time reborn: From the crisis in physics to the future of the universe".

I might even try to write a review of it once I get to read it.

Lee Smolin seems to be expanding on his thesis that the laws of physics evolve in time. Which is what Stephen Wolfram has been saying as well albeit from a much more algorithmic point of view.

James Arathoon

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James Arathoon
 19 April 2013 03:08 PM
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jarathoon

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"DEFINITION

Energy is a commodity that causes a Body to perform Work, at some time in the Future, if and when it suffers an acceleration"



Ken,

How long into the future do would you recommend we wait before giving up on your definition? Geological time?

Having thought about your definition some more, I now realise the definition vaguely refers to macroscopic stored energy. But that does not tell us whether or not, on the microscale, the energy is stored dynamically or statically or some combination of the two.

However even ignoring the the fact that the physics is too vague for a "rigourous" definition, I can also point to the fact that your English sentence constuction is non-rigourous and imperfect as well; the "it" preposition you use could refer to the word "Energy" or the word "Body".

So as you only wanted one reason for not accepting your definition as rigourous, please accept one that any young persion studying for their GCSE English "should" be able to give. It can be read in more than one way!

Trying to find fault in what other people say is fun as well as educational. So I hope you will take my criticism in good spirit.

Part of the nature of qualitative discussions is playing with, coping with, constraining and reducing (but never quite eliminating) "vagueness". It is much more of an art than a science, and needs to be experienced as well as learned.

Quantitative definitions such as "Energy" = "Force" x "Distance Moved" can be learned. However as soon as you have learnt them (plural) you realise that they do not tell the whole story (they always seem to have their own limited domain of applicability) and inconsistencies can often arise on domain boundaries.

With the rise inter-disciplinary science and engineering we need to think more carefully about how we approach new problems on unfamiliar domain boundaries.

I read an interesting comment on another website full of cheap words, which related scientific "rigour" with scientific "mortis" in a rather funny way. I wish I could remeber where I found it.

James Arathoon

P.S. To be clearer the earth has a solid inner iron core, with a molten outer core.

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James Arathoon
 19 April 2013 07:11 PM
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westonpa

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We need only the definitions and understanding that allows us to either protect ourselves against energy or else make good use of it or else create a form which we can make good use of. We do not need some holy grail definition in order to live our lives. At this time we cannot go back in time even 1 day let alone billions or trillions of years and thus no matter what theory someone comes up with we will not be able to prove it is the holy grail answer because there will always be something which we do not know until we know everything. I cannot define love but I can feel it and know it and do I really need to define it in order to know it and enjoy it? All that happens is someone comes up with an understanding and some experiments are conducted which seem to prove that understanding and then if the majority agree that becomes the accepted definition. But it does not mean it is correct in universal terms but does that really matter if it is correct enough for humanity, at that time, and it allows us to progress our knowledge and make good use of it? Whatever name we attach to the something we now call energy something exists and without it we would have no life and whether I can define it or not still I know it exists.

The real questions are what started the very first movement and why and how?

Regards.
 19 April 2013 08:22 PM
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kengreen

Posts: 400
Joined: 15 April 2013

Sorry everybody,
A Post has just come home to roost - seems I pressed a wrong button(s).. Bad habit !

Dear James,

I am indeed delighted to receive your reply to my Posting; exactly the kind of speculation for which I was hoping. You don't agree with me ? Well, my elder daughter does agree with me up to a point because she does not fully understand what I talk about ! You should not agree ; the probability is that neither of us know anything of importance.

I started my 50-year marathon because I grew tired of the easy cliches that were thrown at me daily by people who should have known better. I soon convinced myself that the real problems were concepts such as energy - there HAS to be something cock-eyed in a system that digs coal from the ground, "burns" it to convert water to steam, uses tat steam to drive spinning machinery, uses that machinery to generate "electrical power", sends that "power" over cables to some distant place where it is finally used to do Work.

BUT

at the end of the day all that has been accomplished is the transformation of Heat into Heat. Somewhere there is a payoff in that a great ship (say) has been created ? Raise such a query and you immediately get buried in an endless stream of mathematical jargon which, I believe, is but an excuse to dodge the pain of thinking.

(b.t.w. I must apologise for spelling mistakes which avoid my once eagle eye - I am now a one-finger typist!)

And NO. I regard FORCE as the one reality. Although I'm damned if I have the slightest idea as to what it my be. I ended with a single fundamental particle which enabled me to predict - no test tubes nor bunsen burners - that Helium could not show a Triple Point. It was all in relative measurements with either 7 or 9 (not sure which) simultaneous equations - for which I could supply only three variables. Enter a Sinclair QL computer; set up nested FOR/NEXT LOOPS for each unknown and in a program which (originally) ran for 17 hours came up with a puzzling picture. Progress required that I extend my cogitations up the Periodic Table and so derive some real constants that could be checked against published figures. At that popnt I achieved a massive heart-attack; I was too cussed to die but my memory and concentration faired less well. Since then I have spent 17 years in a wilderness and only in the last month or so have returned. Alas the last of my Notes have been lost but I am practising my technical writing by trying to recreate my BOOK from memory'

Clearly it's time I went back to \Bwd.

My thanks for your response.

Ken Green

Dear James,

Edited: 01 May 2013 at 05:20 PM by IET Moderator
 19 April 2013 08:41 PM
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kengreen

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My Dear James,

Now that is MUCH better. We seem to be heading for a mutual education effort - and who am I to interfere with this?

But seriously I am (was ?) known for my ability in exposition. My questions were serious ... you still have not given a reason for dismissing them as uneducated.

As for these haemorragic devices they call computers?

Ken Green
 20 April 2013 12:30 AM
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kengreen

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Dear James,

Back along a bit you referred to an article by Lee Smolin on that vexed question of Time. In a less alert moment Einstein proposed an evil alliance between three-dimensional Space and zero-dimensional Time. (3 + 0 = 4 ?) Tut tut. Since then the lunatic fringe of Physics has pursued a foolish dream of historic fame and have gathered a lot of fun in the process. My appeal is that during the relatively-short time left to our civilisation we make an effort to return to reason.

Extrapolation back through time to uncover a fanciful Big Bang has to be the most outrageous desicration of OUR laws of mathematics. A sort time ago New Scientist reported an experiment in which it was claimed the equipment was maintained at a few tenths of a degree above 0-K. There cannot be a zero on the Kelvin scale. The approach to such a zero is asymptotic ; it is essential to plot temperature on a logarithmic scale where a zero there is NOT.

Ken Green
 30 April 2013 12:12 PM
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sandip

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To me energy is the stored capacity carry out certain activities.It is mainly two types 1.Potential Energy & 2.Kinetic Energy.In simple explanation KE is required to overcome any obstacle while PE is gained automatically due to its position.
 30 April 2013 12:12 PM
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sandip

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To me energy is the stored capacity carry out certain activities.It is mainly two types 1.Potential Energy & 2.Kinetic Energy.In simple explanation KE is required to overcome any obstacle while PE is gained automatically due to its position.
 30 April 2013 03:01 PM
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Zuiko

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is energy a real thing?

yes
 01 May 2013 01:02 AM
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kengreen

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Ah, Zuiko, So you join in the assault on Ken Green ?

But I am still waiting for James to explain his reason for summarily dismissing my definition of energy; after all it was derived from HIS Physics - not mine . And that one definition covers both kinetic and potential energy ?

Hence my denial ... Energy is a figment of the mathematico-fantasising Mind.

Ken Green
 01 May 2013 11:56 AM
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jarathoon

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Ken,

I think it is pretty clear to everyone reading this, that I see the world completely differently from you. That much can be agreed.

You have spent a large part of your life trying to come up with a rigorous definition for energy, something you now don't actually think is real. I don't think the definition you gave above is rigorous, because it does not cover all forms of energy, both potential and kinetic as you claim.

I think you may know this, as you tell us that you have done all this work, not because you believe that this definition of energy could be used to refer to something real, but because it forms part of some wider scheme to prove that energy is a figment of our collective imaginations.

Now conceiving energy as a sort of stored "Force" (or "Pressure"), and making "Force" (or "Pressure") the primary concepts instead of energy (or perhaps energy density) is how you would like to construct your world view.

Well that is indeed one way of looking at the world, and even one of the ways of studying the world mathematically for that matter.

Look at how much Newton achieved without Leibniz's early concept of kinetic energy "vis viva". Look at how both Newton and Leibniz valued mathematics, as a way to clarify one's thoughts and deductive arguments.

Not only do I see the possibility that energy is both primary and real, I also see that more than one point of view is possible. Indeed many more than one point of view can be developed mathematically and defended, within the array of limited domains of endeavour that we work in.

I also see that mathematics must form a part of which ever view we take, even your view. I value mathematics, and I expect you do as well, if truth were known.

Now I am going to try to get to the heart of what is going wrong here...

Bertrand Russell first realised, that in accepting the possibility of multiple views, you can easily get yourself into the position of the art critic, as opposed to the artist.

The art critic being someone who claims to be able to explain and classify all the great art ever created, yet at the same time has no ability to create new directions in art or even see from what direction the new art movements may come from.

However the art critic, despite his inability as a creative artist, does play an important role in inspiring and training future creative artists. This almost verges on the paradoxical.

Not all artists succeed in creating great art, but some do. Even if they do produce something original, there is absolutely no guarantee that an artists work will be appreciated in their own lifetime or indeed appreciated for ever after it becomes well known.

I have found that sometimes people need quite insular, eccentric and narrow ways of looking at the world in order to help them concentrate and fully focus on the particular problem, or the instance of a more general problem, that consumes them. This seems to apply to artists as much as anyone else, including engineers exploring a new field.

I write this, Ken, because what you are saying from my point of view appears to be nonsense, but I accept that my view (of what you are trying to say) may be completely wrong; not necessarily because I am at fault in my reasoning, but because I don't see and understand the full context of what you are trying to do and say.

James Arathoon

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James Arathoon
 01 May 2013 12:36 PM
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Zuiko

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Indeed many more than one point of view can be developed mathematically and defended, within the array of limited domains of endeavour that we work in.


That may well be the case; but the hypothesis, then the mathematics must stand up to experimental scrutiny.

If the hypothesis and maths do not agree with experiment, they are wrong. An obvious case here is the billions spent on experiments at CERN to test hypothesis. Natural philosophy just doesn't cut it.
 01 May 2013 12:46 PM
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Zuiko

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Here i use acceleration in its Mathematical incarnation ; i.e. a change in either/or speed and direction.

(1) Do you consider that to be rigorous ?
2. Does it describe kinetic energy or static energy?



acceleration is, as you say, a change in velocity.

That is not just rigourous, it is the definition.

A very good experiment which shows the conservation of energy in accelerating objects is the commerical production of x-rays using the Bremsstrahlung method. A moving particle undergoing negative acceleration loses energy (the change in velocity is negative, so change in energy is negative); and an x-ray of exactly the same energy as that change in energy is produced.

Edited: 01 May 2013 at 01:07 PM by Zuiko
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