Template talk:Classical mechanics/Archive 1

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Archive 1

Creation of template

Hi, I just created this template for fun, but I feel it's not very accurate and exaustive. Feel free to improve it as you wish and/or leave comments on my discussion page. Thanks. Frédérick Lacasse (talk · contribs) 23:11, 21 November 2007 (UTC)

here is a comment dont bet on dead horses —Preceding unsigned comment added by 64.90.209.14 (talk) 17:24, 4 February 2008 (UTC)

Newton's notation

Newton didn't have vectors, so perhaps it would be nice to use his original notation of $F={\dot {p}}$ . On the other hand, however, Newton's second is more familiar to most as $F=ma$ or $F=m{\vec {a}}$ . Perhaps the current notation is a pleasant compromise? — gogobera (talk) 00:55, 3 April 2008 (UTC)

Change the sub-legend

I propose the diagram's sub-legend 'Newton's second law of motion' be changed to 'The second law of motion of classical mechanics'.

The diagram is mistaken because its sub-legend 'Newton's second law of motion' is historically mistaken and if anything should be rather 'The second law of motion of classical mechanics'.

This is certainly not Newton's second law stated in the Principia, which was that THE change of motion [referred to in the first law] is proportional to the motive force impressed, i.e. Dmv @ F, or F --> Dmv (where 'D' = 'the absolute change', Delta, '@' = 'is proportional to', and '->' is the logical symbol for if... then...).

The misrepresentation of Newton's second law as F = ma or similar has the logical consequence that a = F/m and thus a = 0 when F = 0, whereby Newton's first law would be logically redundant just as Mach claimed it was.

But Newton's second law only deals with changes of motion produced by impressed force such as mentioned in the first law, and does not itself assert there is no change of motion without the action of impressed force as the law F = ma does, where F denotes impressed force rather than inertial force. And in fact both Galileo's 1590 Pisan impetus dynamics and Kepler's 'inertial' dynamics, both of which claimed motion would terminate without the continuing action of what Newton called 'impressed force', denied this principle.

But the logical function and historical purpose of Newton's first law is precisely to assert this principle, that there is no change of motion unless (i.e. If not) compelled by impressed force, and thus whereby Dmv <=> F, rather than just F --> Dmv. (Here <=> is the logical equivalence symbol for 'if and only if', and '-->' the symbol for 'If...then...') Thus Mach’s logical criticism was wrong by virtue of his ahistorical misinterpretation of Newton’s second law as F = ma.

Classical mechanics, whatever that might be, needs to be differentiated from Newton's mechanics.

--Logicus (talk) 18:20, 16 April 2008 (UTC)

Hi Logicus. Well, I don't know. The article on Newton's laws of motion says that the Newton second law is "The Rate of change of momentum is proportional to the resultant force producing it and takes place in the direction of that force". Isnt it the same thing that the formula on the template? (or maybe according to you, both article and template are wrong?) I do not oppose you change the sub-lengend, but honestly i'm not sure i see a true difference. Even if the formula is not as Newton stated it, it's greatly inspired by no :)?? And history remembers it as the Newton second law (improved?). Am I wrong? But your comment is interresting. Is this information on Newton laws of motion article???

Frédérick Lacasse (talk · contribs) 13:03, 17 April 2008 (UTC)

First of all, the relevant text is at wikisource, and I'll begin by saying that I disagree with Logicus on her/his proposal. Newton's second law is not stated, as such, mathematically. (Perhaps it is later in the Pricipia, I do not know.) For clarity, its statement under Axioms, or Laws of Motion reads:

The alteration of motion is ever proportional to the motive force impressed; and is made in the direction of the straight line in which that force is impressed.

(Emphasis mine, in order to make clear that this is certainly an if and only if statement. Note that Logicus has failed to quote that word in presenting his/her argument.) Since Newton used Calculus in conjunction with this law to calculate planetary orbits and such, it is not too crude to use modern calculus notation in the box, even if we choose Leibniz' $\mathrm {d} /\mathrm {d} t$ notation over Newton's dot. For that matter, we use vectorial notation when Newton had none. Therefore, clearly, in modern notation, Newton's second law reads

${\vec {F}}={\frac {\mathrm {d} }{\mathrm {d} t}}m{\vec {v}}$ , and I have no problem with identifying this equation (or an equivalent one) as Newton's Second Law or Newton's Second Law of Motion. Or, see Goldstein, Poole, and Safko, Classical Mechanics (3rd ed.) page 1, where $\mathbf {F} ={\frac {d\mathbf {p} }{dt}}\equiv {\dot {\mathbf {p} }}$ is identified as Newton's second law of motion.

Regarding the other stuff you've said about Mach, historical interpretations, and other irrelevant (for the purposes here) things, perhaps this can help. Newton's second law, which can be expressed as $F=ma$ cannot imply that "Every body perseveres in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed thereon" (Law 1), without presupposing the existence of inertial frames, which is what the first law, in effect, does. The fundamental disconnect between Newton and Mach, as I understand it, concerns the existence of a preferred inertial frame.

If, unlike I've read in many sources over the years, you have sources that claim Newton never equated force with a time-rate-of-change of momentum, you might be able to begin to find people willing to change their ways. However, the classical mechanics template talk is not the place for that discussion. — gogobera (talk) 20:10, 17 April 2008 (UTC)

Logicus's response to Frederick Lacasse, written before Gogobera's contribution: Thanks Frederick. Yes, BOTH the article on Newton’s laws of motion and the template are wrong, because the article mistranslates the Principia’s second law’s phrase 'mutationem motus' as ‘rate of change of momentum’, whereas it should be ‘The change of motion’, with no reference to any rate of change. It referred to an absolute change of motion as produced by an impulse, as in Cartesian vortical mechanics. May I refer you to Bernard Cohen’s ‘Guide to Newton’s Principia’ in the 1999 Cohen & Whitman Principia new translation for a good discussion of this issue, which was also touched on in the recent BBC Radio 4 ‘In Our Time’ programme on Newton’s Laws of Motion and drew the following comment from a listener published on the BBC website @ http://www.bbc.co.uk/radio4/history/inourtime/inourtime_haveyoursay.shtml

“Andrew, Newton's 3 laws

Simon Schaffer might have done well to see in this archive (dating from the programme on Popper), "if you study the original version of Newton's Second Law - not the modern F=ma - you realise that Newton regarded force as a function of time, equivalent to the modern notion of an impulse. It was change of momentum: mass *or* velocity; thus even if mass increases with increased velocity so does the force required, and Newton holds." The insertion of 'rate' in 'rate of change of motion (momentum)', giving F=ma, isn't a flaw of Newton's - it's a mistranslation of 'mutationem motus'. “

The true difference, as I have already pointed out, is that rather than Newton being illogically foolish in his axiomatisation is respect of stating a logically redundant axiom, namely Law 1, as Mach implied, because it was logically entailed by his Law 2, rather his first law states a logically independent axiom which, for example, ruled out Kepler’s theory of inertia according to which the inherent force of inertia resists and terminates all motion. For in Newton’s theory which revised the keplerian theory of inertia the force of inertia only resists accelerated motion and causes uniform straight motion like impetus did in late scholastic Aristotelian and Galilean impetus dynamics.

This is all important for understanding the logic and history of scientific discovery and such as how and why ‘classical mechanics’ emerged, the project started by Duhem that was the major research project of 20th century history and philosophy of science.. But there seems to be some considerable logical confusion and contradiction in Wikipedia articles about Newton’s dynamics and about classical mechanics and what it is and how it relates to Newtonian mechanics. For example the article on ‘Classical mechanics’ says on the one hand the two are equivalent, but on the other hand they are not equivalent because classical mechanics was created later and goes well beyond Newton’s mechanics, as in the following statements:

“There are two important alternative formulations of classical mechanics: Lagrangian mechanics and Hamiltonian mechanics. They are equivalent to Newtonian mechanics, but are often more useful for solving problems.”

Versus

“While the terms classical mechanics and Newtonian mechanics are usually considered equivalent (if relativity is excluded), much of the content of classical mechanics was created in the 18th and 19th centuries and extends considerably beyond (particularly in its use of analytical mathematics) the work of Newton.

This confusion needs sorting out, but a bigger job than I have time for. I was just trying to reduce this confusion a little, as it cropped up on the Galileo article, but I now see this diagram is pretty ubiquitous in relevant articles. Sorry just to pick on your otherwise no doubt helpful diagram.

I fear the article on Newton’s laws of motion is currently virtually wall to wall ahistorical nonsense, apparently being devoted to teaching some version of 19th century mechanics or A-level Physics rather than the history of physics.

Re your following comment

“Even if the formula is not as Newton stated it, it's greatly inspired by no :)?? And history remembers it as the Newton second law (improved?). Am I wrong?”

One problem with the first claim that Newton greatly inspired the law F = ma is that the Wikipedia classical mechanics article is currently claiming

“The proportionality between force and acceleration, am important principle in classical mechanics, was first stated by Hibat Allah Abu'l-Barakat al-Baghdaadi,[7] Ibn al-Haytham,[8] and al-Khazini.[9] “

- although I have no idea whether this is true or not.

All in all I think I should implement the proposed edit if you have no further comments or objections. But it is still unsatisfactory given it is unclear from Wikipedia what exactly classical mechanics is, whereby such as Lagrangian and Hamiltonian mechanics and even Newtonian mechanics are said to be alternative formulations of it.

The outstanding pedagogical question for your view is surely that if you claim that Newton’s second law was essentially

F = ma, then why did he think he needed to state the first law as his first axiom ? The simple answer is because it gives the equivalence between change of motion and the action of impressed force that the second law does not, because the second law is only at most Dmv α F and not Dmv = F.

--Logicus (talk) 20:34, 17 April 2008 (UTC)

See Talk:Newton's_laws_of_motion#Change_the_.27Classical_mechanics.27_diagram.27s_sub-legend_.3F for the continued discussion. — gogobera (talk) 18:51, 25 April 2008 (UTC)

Source regarding Galileo and Kepler

Logicus has requested sources backing up the relevance of Kepler and Galileo to the history of classical mechanics, so here it goes:

The relevance of both Galileo and Kepler is discussed in this Encyclopedia Britannica article: mechanics.--ragesoss (talk) 19:49, 28 July 2008 (UTC)

Logicus did not request sources backing up the relevance of Kepler and Galileo to the history of classical mechanics, contrary to Ragesoss's claim thnat he did. Rather the box diagram represents classical mechanics as characterised by the dynamical law F = ma in effect, and Logicus was asking for any justification that Kepler's Aristotelian dynamics espoused this law, when in fact it did not, or that Galileo's dynamics did, when in fact it did not. The list of those of relevance to the history of classical mechanics if this is to include its pre-history before Newton would surely be every dynamicist beforehand from Aristotle and the atomists ?

And if ragesoss has time to be looking up encyclopedia references, perhaps he would also be gracious enough to find time to comply with Logicus's reasonable outstanding request that he either demonstrates or withdraws his accusation that Logicus made a Wiki Personal Attack on Deor. (See User talk:Ragesoss)

The box makes no claims that Kepler or Galileo espoused this law. It simply implies that they are, in some unspecified way, associated with the law and its history. It's clear that Galileo and Kepler, because of their mathematical work in dynamics and its contribution to Newton's thinking, are among the more relevant figures in the pre-Newton history of dyamics. I'm certainly willing to entertaining adding some others, though, if there's a good case for their significance. As for personal attacks, I'm choosing to ignore that for now, since I find those kinds of disputes extremely unpleasant. Please, just try to treat other editors with a little more respect.--ragesoss (talk) 14:14, 29 July 2008 (UTC)

It seems abundantly clear that Galileo and Kepler are related to the history of classical mechanics, so I'm removing those tags.-Oreo Priest ^talk 16:02, 30 July 2008 (UTC)

And it also seems abundantly clear that Kepler and Galileo did not subscribe to Newton's second law of motion, which the diagram clearly represents in big letters as the characteristic defining law of classical mechanics. It has long been generally accepted at least since Koyre pointed it out both in his Galilean Studies and Astronomical Revolution that Kepler subscribed to (Thomist) inertial Aristotelian dynamics with its law v @ F/m ('@' = 'is proportional to'). According to Koyre, albeit mistakenly, Kepler's dynamics was the last appearance of Aristotelian dynamics. (In fact classical mechanics is a distinctive development of Aristotelian dynamics pioneerd by Newton.)

And the basic premise of Duhem's famous A constant force produces a constant acceleration was precisely that Galileo did not arrive at this principle of classical mechanics, but that it only emerged afterwards, formulated by one of his students as I recall..

But of course I do not deny Kepler and Galileo are somehow related to the pre-history of classical mechanics. But then equally so are such as Benedetti, de Soto, Oresme, Buridan, Averroes, Aquinas, Avicenna, Philoponus etc in an enormous list going back to Aristotle and the atomists in the long millenial evolution of classical mechanics from, antiquity. But that would surely be absurd. Classical mechanics, as the Wiki article on it says, really begins with Newton's dynamics.

Thus I am deleting Kepler and Galileo, whose inclusion in this list is utterly educationally and historically misleading and confusing. --Logicus (talk) 17:39, 30 July 2008 (UTC)

May I recommend you actually look at the diagram here, where you should see that almost half the box features a statement of Newton's Second law, and then it says "History of...". But whilst Kepler and Galileo were listed in "Scientists" for some unspecified reason, notably they are not listed in "Formulations", presumably for the very good reason that they did not formulate any variant of classical mechanics.

And by the way, why on earth is Cauchy listed ? --Logicus (talk) 17:52, 30 July 2008 (UTC)

Deletion/addition: I propose Cauchy be deleted from the 'Scientists' section, and Clairaut be added, at least for his development of perturbational analysis to predict the return of Halley's comet, which the 1713 second edition Principia had only predicted by curve fitting, and was two years early.--Logicus (talk) 17:18, 4 August 2008 (UTC)

Hertz should surely definitely be included in the list of classical mechanics scientists by virtue of his 1894 Principles of Mechanics as an important distinct variant of classical mechanics. For example, it seems that what is taught at such as GCE A-level Physics as 'Newtonian mechanics' is in fact not such, but if anything really Hertzian mechanics, which was based on the concepts of space, time and mass, but excluding force, whereas the notion of force, and especially inertial force, is basic to Newton's Principia mechanics, no less than 6 of whose 8 formal definitions were concerned with defining forces.

It seems one hallmark of the difference between real historical Newtonian mechanics, understood here as 'the mechanics of Isaac Newton's Principia', and what is taught in contemporary educational institutions as 'Newtonian mechanics', is that in the latter there is only one operative force in gravitational free-fall, that is, gravitational fall in a vacuum, namely the impressed force of gravity, whereas in Newtonian mechanics there is also the body's inherent force of inertia that resists the impressed force of gravity. For as Newton said of the force of inertia,

"Moreover, a body exerts this force [of inertia] only during a change of its state, caused by another force impressed upon it, and this exercise of force is...resistance " [p404, Cohen & Whitman 1999 Principia]

And in real Newtonian mechanics it is by virtue of the constant proportionality of the motive force of their gravitational mass and the resistant force of their inertial mass that all unequal weights would fall with the same acceleration in a vacuum. --Logicus (talk) 15:44, 15 August 2008 (UTC)

In his 1995 'Newton's Principia for the common reader', Chandrasekhar takes Maxwell's 1877 formulation of classical mechanics as the canonical version of Newtonian mechanics. I propose he should therefore be included in the list of scientists. --Logicus (talk) 17:52, 19 August 2008 (UTC)

List of articles (Article section)

I compiled a list of all articles that I've found related to Classical Mechanics. I think it is important start indexing/listing all the articles that have direct relation with Classical Mechanics. Knowing what articles are out there will force editors to start thinking about the individual articles in context. This will provide structure to the topic of mechanics, avoiding duplications and improving the overall reading of the articles. The current form of this section is not the way it should be. It is just a first step. I better way to present the navigation box should be thought and discussed. For example: Do we need sections on Dynamics of particles, Dynamics of rigid bodies, statics, etc... Comments? - Sanpaz (talk) 03:58, 22 September 2008 (UTC)

I just realized that this list of articles should be included in a navigation box for Dynamics, the same way that Continuum mechanics and Statistical mechanics have an individual navigation box. That means other Branches that do not have a navigation box need one. I will try to create a Dynamics navbox - Sanpaz (talk) 04:08, 22 September 2008 (UTC)

Template is confusing when reading articles it is used in

I initially found this template confusing in the articles it is used because it seemed that the equation which is shown had something directly to do with the article. It took a moment to realize that it is just being used symbolically to indicate a classical mechanics article. So I assume other people might also find this confusing (maybe more or less than myself!)

I suggest therefore that either the presentation of the formula be changed so that it looks more like a symbol (I'm not an art student however...) or something else be used instead.

Thanks Dhollm (talk) 13:19, 7 October 2008 (UTC)

Fluid Mechanics?

Isn't Fluid Mechanics (or Fluid Dynamics) a branch of Classical mechanics in its own right? Why do we not include it? --BozMo talk 10:26, 3 February 2009 (UTC)

Fluid Mechanics is part of Continuum mechanics sanpaz (talk) 13:45, 3 February 2009 (UTC)

Not in any department I have worked in but technically I suppose...--BozMo talk 13:26, 4 February 2009 (UTC)

Cauchy

I am of the opinion that Cauchy should be included in this template, as he originally formulated the stress tensor, now fundamental in solid and fluid mechanics. Any thoughts? Thudso (talk) 15:33, 11 December 2009 (UTC)

Fundamental concepts

Ok. Let's first define which ones are Fundamental concepts (instead of calling them Basic concepts): Space, time, velocity, speed, acceleration, gravity, mass, force, momentum, angular momentum, inertia, moment of inertia, reference frame, energy, mechanical work, virtual work, D'Alembert's principle. Please add or delete some. But, for me these are fundamental quantities or concepts for classical mechanics. Taking any o those away does not make sense. For example: Including force, and not momentum?. Or Energy, and not work? I never subscribe to the idea of too complex or to advance for readers. Things are the way the are. Objects in the universe have inertia, you cannot hide that concept from readers just because you think is too advance. The way you explain the concepts inside the article is the way you make things clear to readers. sanpaz (talk) 19:59, 9 April 2010 (UTC)

Core Topics

What are the core topics of Classical mechanics? First, motion comes to mind. So, Motion, Newton's laws of motion, Equations of motion (I disagree with the title of that article), Circular motion, Uniform circular motion, Non-uniform circular motion, Harmonic oscillator, Simple harmonic motion. Now, all other links are part of some or all of these motions. I know that right now these core topics are too many. But the problem with so many links is due to the fact that a lot of those article should not exist but should be part of one single article. For example, centripetal force, centrifugal force, angular velocity, angular acceleration, Uniform circular motion, Non-uniform circular motion, should be part once single article called Circular motion. But that is another big issue that cannot be solved right now in this template. So the only thing we can do at this moment is to include all articles related to circular motion. sanpaz (talk) 20:32, 9 April 2010 (UTC)

Too big?

The template seems far too big now, and so much less useful. Compared to this version there are two related problems. The sheer number of links is overwhelming, with the 'Fundamental concepts' section, probably the first one users will look at, by far the biggest recipient. That makes it much less accessible. It used to just contain the genuinely fundamental concepts Space, Time, Mass, Force, Energy and Momentum. Now they are difficult to find among the other topics which range up to university level topics. Apart from this there's some redundancy: duplicate links and extra words.--JohnBlackburne^words_deeds 09:57, 9 April 2010 (UTC)

It is big. However, every single concept (link) is necessary to cover classical mechanics. Space, time, mass, force, energy and momentum, are indeed fundamental concepts, but the same can be said about acceleration, frame of reference, velocity, distance, etc. The navigation panel needs more thinking, it needs a better way to organize all these concepts in a logical way. But I would not go as far a to eliminate all links just because it is too big.

Another issue is the number of articles, which can be reduced. Most of the articles on classical mechanics were created and developed individually without thinking necessarily about the big picture. That is why we have a lot of repetition in certain topics. For example, the concept of circular motion and all of its parameters (angular velocity, angular acceleration, centripetal and centrifugal forces) could be merged into just one article. This is something that needs to be done.sanpaz (talk) 15:26, 9 April 2010 (UTC)

The point is not to cover all of classical mechanics in a single navigation box. See the guidelines in WP:NAV, especially the first few properties: "They should be kept small in size". I would say the template as it is is a good example of a navigation box too big and confusing to be useful: the fundamental concepts section in particular. So I've made a start at reorganising it. Bearing in mind what you've written I'll try not to remove stuff, unless it clearly duplicates something else. --JohnBlackburne^words_deeds 16:07, 9 April 2010 (UTC)

That was a good change. I see some links disappearing with time. For example, as I said before, angular velocity, angular acceleration, etc, when those articles get merged with the article on circular motion. Also the article on uniform circular motion should be merged too.sanpaz (talk) 16:14, 9 April 2010 (UTC)

OK, I've tried fixing it as best I can. All the links that were there should still be there, but in smaller groups. I've put them in what I think's a sensible order but it's fairly arbitrary, as are the titles. And I've done little to order the topics in the larger groups, except for trying to keep them in the same order as I moved them. I agree there are a lot of headings that seem redundant, but I don't hold out much hope for them being merged. It's the nature of the subject I think.--JohnBlackburne^words_deeds 16:27, 9 April 2010 (UTC)

Your edits seem reasonable. I still have reservation with dividing rotation motion from Basic Motions. I will think about how to better show that.

My hope with this navigation panel is that it will make people think it context. Make every one realize that there are other articles that may talk about similar things and that they perhaps need to be merged. It is always importat to see the big picture (Classical mechanics) when editing individual articles.sanpaz (talk) 16:37, 9 April 2010 (UTC)

I think more changes need to happen. Some links such as inertia, moment of inertia, fictitious forces and others are not core topics but basic concepts. Perhaps, Core Topics, Basic Motions, and Rotational Motion need to be merged into one section called Core Topics or something similar. sanpaz (talk) 17:10, 9 April 2010 (UTC)

Ok, so this is what I have done in the last edit:

I included Gravitation, and Newton's law of universal gravitation in the basic concepts.
I think we can agree that Branches, Formulation and Scientist are pretty much fine. But I moved Branches and Formulations to the top to show how Classical Mechanics is organized and formulated before getting into concepts.
I moved some links into Basic concepts, such as inertia, moment of inertia, frames of references, torque, mechanical work and virtual work. These are concepts, not topics.
Moved inertial frame, no-inertial frame into topics. sanpaz (talk) 17:24, 9 April 2010 (UTC)

It seems much worse again, the main problems being

The 'Basic concepts' includes stuff that is far from basic. There should be section with just
- Core building blocks of mechanics, i.e. mass, time, space, energy
- Approachable, topics, so anyone can read them

this to me rules out things like moment of inertia, reference frames and D'Alembert's principle: all too advanced and not at all fundamental - or if they are then so are a dozen more, so the core topics should be merged. Except...

The core topics section is again too large, so very difficult to find things in or get a good sense of. Splitting out the rotational topics was the first thing that came to mind to fix this, but there may be other ways. It's especially a problem as the two headings "core topics" and "basic concepts" mean much the same thing, so it's as if 80% of the topics are under one heading.

On the last point it's not clear what the "core topics" section should be called (the previous name was "fundamental concepts" but that means much the same, and was applied to just Space, Time, Mass etc. at one point). Splitting it up so it's not so big would make it clearer: into rotational and non-rotational topic would be one way, but there may be others (and it could be into more than two).--JohnBlackburne^words_deeds 19:35, 9 April 2010 (UTC)

I think it could be a good idea to split something into linear motion and rotational motion. I'm keeping my comment vague, because I'm just throwing an idea. Headbomb {talk / contribs / physics / books} 09:06, 13 April 2010 (UTC)

I think that is the best approach. Some mechanics books (engineering dynamics books such as Beer and Johnston, or Hibbeler) describe the dynamics of a particle first considering linear translation, then circular motion. Later they describe rotation of rigid bodies. Which reminds me that the distiction between particle dynamics and rigid body dynamics is not yet clear in the template. sanpaz (talk) 15:54, 13 April 2010 (UTC)

Reasons for including Horrocks and Clairaut in list of scientists?

I am interested in the justification for including Horrocks and Clairaut as significant contributors to the field of classical mechanics. Admittedly, I have not come across either of them in all my study of classical mechanics (the prominence of all the others is quite evident). Their pages here do not suggest any major contributions, no does their lack of fame - if someone can provide sources however, I'm perfectly willing to change this view. Noldorin (talk) 23:47, 25 January 2011 (UTC)

Confusing illustration

The infobox carries the equation F=d/dt(mv) as an illustration. This is not helpful in the article Kinematics, which is described as the study of motion without consideration of the forces that cause the motion. The force equation causes confusion between Kinematics and Kinetics. Could we have some other illustration? Perhaps a piston rod, some gears, a pendulum, or whatever. --LA2 (talk) 12:16, 17 August 2010 (UTC)

I absolutely agree--I ran across it in another article where it was not helpful. Given that your comment has been ignored for two years, I might go ahead and boldly delete it. Ideas: A picture of Newton? One could use some random diagram such as the parabolic trajectory in Classical mechanics, but that's too specific and would surely be confusing in some other article.Ccrrccrr (talk) 00:55, 17 April 2012 (UTC)

Picture proposal

This template has a history of illustration struggles... So I thought one which shows the essence and fundamentals of classical mechanics in a simple illustration would help:

It shows the particle has a fixed mass m, and moves in a deterministic path (note the particle has traversed a definite past and will traverse a future path), also showing the absolutely fundamental dynamical variables of q (the generalized coordinate, i.e. configuration) and p (generalized momentum, i.e. motion), as functions of time t, from which all dynamical variables can be derived from. Any objections to inclusion? Is it too obscure or mysterious? M∧Ŝc²ħε И_τlk 10:12, 26 February 2013 (UTC)

"Obscure" and "mysterious" weren't the first descriptions that came to mind here – it was "intriguing" and "attractive". Whether that'd be too intriguing / attractive for the picture's place in the article, I don't know – but I guess there's one way to find out. Thanks for creating / finding! CsDix (talk) 13:18, 26 February 2013 (UTC)

PS I suppose one possible objection might be that the diagram resembles something more from high-energy particle physics than classical mechanics, but, if this objection is made, the mass m could be made to look more like that old staple: a snooker / billiard / cue ball..? CsDix (talk) 13:22, 26 February 2013 (UTC)

Thanks for positive feedback! However, the particle is to resemble a general material particle (the tones/shading are supposed to be twirled reflections on the surface), which the reader may mentally substitute for a ball etc. Using a cue ball for the path in this picture isn't a very good idea, but I could draw another pic to show the trajectory of cue-looking balls hit and showing position, momentum and angular momentum conservation ("spin" of the ball as it's knocked)... M∧Ŝc²ħε И_τlk 16:25, 26 February 2013 (UTC)

One possible alternative is to just use an an excellent and helpful high-quality animation of Newton's cradle:

[[Image:Newtons cradle animation book 2.gif|200px]]

although it may be (very?) distracting/hypnotizing... M∧Ŝc²ħε И_τlk 16:31, 26 February 2013 (UTC)

I dislike moving pictures because they are distracting. One's attention is drawn to them almost irresistibly. This makes it hard to absorb the article's text. JRSpriggs (talk) 06:39, 27 February 2013 (UTC)

Agreed. Nice though the animation is, I don't think its place is here. So, my preference is still for the diagram. Perhaps the m mass symbol within the particle might be made white (i.e. more visible)..? CsDix (talk) 06:47, 27 February 2013 (UTC)

Done, I didn't make it absolutely white to keep the realism of shading, but it should be more visible now. M∧Ŝc²ħε И_τlk 07:40, 27 February 2013 (UTC)

No opposition to inclusion? There was in this section but that was more generally at all navboxes/sidebars, all other main physics sidebars get to have pictures so I shall just do it... Also de-wiki-coded the above animation if it's distracting... 21:00, 12 March 2013 (UTC)