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Hedgehog signalling maintains the optic stalk-retinal interface through the regulation of Vax gene activity

SMAD3 or Mothers against decapentaplegic homolog 3

+: S×S → S

The article shows a march of ideas, grounded in constraints such as truth, validity, reproducibility etc. and a lessening of the need to exalt one concept over another, except perhaps for our own attention and other resources. Might this be an explicit entry for part of the article. Deduction only yields to Deduction or Induction; Jevon's Plausibility of a Conjecture becomes a defensible effort rather than a waste of time; Evidence becomes just as important as Authority. Should we also include Wittgenstein's concept of the usefulness of Contradiction and Turing's rejection of that discussion? Would that not also allow the entrance into the speculative sciences, to use Roger Bacon's terminology.

These questions may be more appropriate for a philosophical article; in that case we could ignore them; would that be appropriate for a history article? In Max Born, Natural Philosophy of Cause and Chance, Born points out that Cause and Effect can be analyzed no further than that of a mathematical function. Thus he removes them as things to be found like mountains in terra incognita. This removes considerations such as 'First Movers' etc. and considerably simplifies discussions.

Ernst Mach makes a similar point about scientific law; our laws are psychologically dependent, like Occam's Razor. It helps us to simplify and otherwise transform the subjects of discussion, in order to manipulate their properties, and perhaps understand them better. Thus the laws of physics are simple, but the complication lies in the specification of the boundary conditions of the models.

In the twentieth century, statistics and computers came into their own, and we need no longer find only analytic solutions to mathematical functions, instead other techniques such as simulation by the Monte Carlo method were used to build things like bombs, etc.

On another philosophical point, Isaac Newton formulated laws of nature with forces to which we and Nature are subject. This is framed exactly like Roman law in which law started out as sacred mystery, to be passed in secret from father (patriarch) to son (but with a bow to vengance as a motivation for punishing transgressors of law). Then the plebeians demanded equal access to the law and their publication in the Twelve Tables. (Sounds like Wikipedia from 2200 years ago, doesn't it.) The analogy appears to be the personal dependence of scientific method on who is performing the steps. This concept is stated explicitly in the scientific method article itself, as well as the caution that scientific method is not a recipe and requires ingenuity and imagination. What is left unsaid is that it takes a special person to practice scientific method. Is this obvious to those reading a history? Does history take special people only? Is the historical fact that scientists have shown high moral development as well as the ability to maintain a neutral/ objective POV? Might this be myth? Is it possible for scientists to demonstrate that they only are able to practice scientific method? Might that be a litmus test?

There is a parallel situation in mathematics; it takes a mathematician to construct a mathematical proof, although a proof ought to be accessible to non-mathematicians. We do not yet understand how to make ingenuity and understanding methodical enough to satisfy Francis Bacon's dream of a better method. --Ancheta Wis 17:23, 10 February 2007 (UTC)

scholasticism Divine right and Roman law Roman law Oersted We need a community here. Failing that someone might just post this on Craigslist.org: "Wanted: nobel-level leader and expert in physics to devote countless hours on Free stuff. Wikiproject stalled for lack of community." or take it to the community for comment or maybe The Onion. Come on. --1 February 2007 (UTC)

What about setting a timer. After one week, one month, one year, 10 years, 100 years, ... declare the project dead. Draw a Black outline around the article/wip: "This effort is archived for historical purposes only. Please do not modify it." Then forbid any efforts to try again. 09:47, 1 February 2007 (UTC)

This discussion is evidence that the page/wip is dead for want of moderation. That this page not be a total loss, you (the reader) might try the Autobiography of Benvenuto Cellini. Benvenuto Cellini was an extremely talented man of the Renaissance who had the ill-fortune to create works which were in high demand, and who was forced to defend himself, to put it charitably (he had to kill people who wanted to steal from him). I first learned of him through music: Benvenuto Cellini (opera). -- 1 February 2007 (UTC)

This is OR. I suggest finding a venue like WikInfo where your POV will survive. "Wikinfo accepts and encourages original research." The next problem will be to find others who agree with you, and who will then propagate your ideas in the future. It's kind of too bad that Platonism is baked-in to your POV.

Gauss once stated that his work came through systematic, palpaple experimentation (I can't find the location where I saw this quote, unfortunately).

The categorical statement "theory is developed from data, not a wild brainstorm" also does not fit how many people think, including Albert Einstein. Where might data come from, in your scheme. Re-read the Heisenberg paraphrase of Einstein's comments on observation.

Mathematics doesn't come for free, especially the part about observing the logical steps in a proof. It takes mathematicians to do mathematics. Witness the Andrew Wiles proof of Fermat's Last Theorem; it took someone to say "I'm sorry, I can't understand step xxx" to Wiles. Fermat's Last Theorem continued to stump the entire world until Wiles had a brainstorm to save his proof.

Based upon the history of this article, involving hundreds of editors performing thousands of edits, I would be wary of the rocks hiding under the surface of the waters of your proposed voyage.

11:04, 29 January 2007 (UTC)

[edit] Cross-channel interference

27 November 2007 I am struck by the similarity the situation on this physics/wip page and the disorder of autism.

This weekend, CNN broadcast a program, Autism is a World, featuring an autistic person, Susie Rubin, of Los Angeles, California. Susie Rubin carries spoons at all times. When she must, she watches the flow of water from a tap and modulates its flow with the spoons. At such times, she has stated that she ceases to think. Susie Rubin literally did not think until she learned how to use a communicator after 13 years of dysfunctional communication. She states "my mind woke up" after her use of the communicator.

A communicator is an electronic device with a keyboard which serves to rule out words as you type in letters, and which simultaneously allows you to select appropriate words in your message. This is very similar to the use of lexigram keyboards by some research primates in the US, who have learned to communicate words to humans and to each other^[1].

Susie Rubin is afflicted with developmental problems, but the use of the communicator and a 24-hour/day support-person are allowing her to attend Whittier College.

Susie Rubin has behaviors which interfere with communication. She will not look at those who are speaking to her. Her face distorts with the effort of conversation. The subtleties of ordinary communication cannot be observed when attempting to communicate with her, and one must devote extra effort if one wishes to succeed with her. In communications terms, it is as if she has multiple broadcast channels which she cannot suppress even when highly educated people are devoting their full attention to her in conversation. At least one channel of her mind is attempting to attend to such conversation. The use of her communicator proves that she is in fact listening and can respond.

On this physics/wip page, a thread of conversation, asynchronous to the stated goal under discussion will pop-up, between individuals, sometimes antagonist, sometimes cooperative, as observed previously by several people.

It is as if the boiler on a steam engine were suddenly doused with cold water, suddenly lowering the temperature, and destroying the ability of the engine to do work.

This is the reason that I have proposed that we use an alternative page for the article, and the talk page for talk, rather than attempting to restrict work on the WIP page until consensus is reached. A normal wikipedia page works this way, after all. Is it not obvious that the protocol of reverting all edits to the WIP page has dampened the ability of editors to work?

1. ^ Sue Savage-Rumbaugh, Smithsonian Magazine, November 2006

I am pretty sure you are sincere in your comments; just wanted you to know my opinion of the Physics/wip project. I believe that it is a fundamental error in the structure of the project, to mix up talk with the article edits. I have raised this with SFC9394 who appears to wish that this project run on autopilot. Well, I think it pretty clear that a commitment to active moderation is a necessity for the project.

How would you like to be the moderator. You appear to enjoy the word-end of the article. If you like, I can nominate you, but I am not positive that others would like to see a change in the project. In particular, I believe that MichaelMaggs has an interest in keeping the project as is. But if that is the case, then I believe that this project will simply be an example of what not to do and how not to do it.

If you are interested, I will broach the possibility with MichaelMaggs and SFC9394 in particular.

Now this has a side-effect, of which I am perfectly aware. The assumption of the role of moderator will of necessity lessen the time available for direct editing. Having studied this topic for over 40 years now, (with some heavy-duty people, Nobel laureates, founders of industries, etc.) I just want the pleasure of writing about physics, so I am selfish about wanting to remain on the editing side. And I am sincere about collaborating. That is one of the problems with the current project. We are not currently collaborating, by the design of the project. Thus no wiki-action.

My background is one reason I define a physicist as one who has discovered new physics. I leave open the definition of scientist as one who is engaged in the systematization of scientific knowledge, using scientific method. By that definition, everyone working on the page is a scientist, and my teachers are all physicists. --Ancheta Wis 23:06, 22 November 2006 (UTC)

Oxford Companion to History of Modern Science notes that just about year 1800, energy quietly became the basic 'stuff' of physics, with conservation of energy etc coming to the fore in the nineteenth century. But equally, just about 1900-1915, it came to be realized that 'matter' is not quite so basic, even though we are currently enjoying the fruits of the nineteenth century (Maxwell's equations) and the twentieth century (quantum mechanics) at the technology level.

Perhaps we need to be more careful, a bit more agnostic about the stuff of physics. The perennial questions remain. The current disputes over the basic stuff of physics read uncomfortably like debate over the four humors; "It's earth, no it's air, no it's water, no it's fire". Who is right? Those who believed in the five essences? In the current disputes, we all lose. It's as if the dispute were over the deck chairs on the Titanic. In the meantime, University of Reading is closing its physics department by 2010.

The WIP page appears to be framed incorrectly. Hopefully someone will write up a post-mortem. Specifically, the constraints on the page might be taken like the design of Hagia Sophia (or some of the other famous structures), why did it fail?

On a more positive note, might I propose that scale be a nice point from which to write up physics. The huge range of orders of magnitude in its fundamental concepts is distinctive to the science. And it's even the same equations, largely. Joshua Davis made this point already. But matter dissolves at high-enough energies, leaving only what?. If the system were to cool down again, would we again return to the current constructs of Nature? Or might it be like life, where a species rarely returns to dominance, once wounded. A survivor species might get the jump on the wounded species, as on the slopes of Mt. St. Helens. The same points apply to a business or industry, by the way, 'You cannot step in the same oilfield twice'. --Ancheta Wis 18:32, 20 November 2006 (UTC)

In geophysics, the Dahm discontinuity ^[1] is a sharp discontinuity overlying a 200-km-thick low-velocity layer just above the Earth's core. Cornelius Dahm found this from seismographic data on the Tango, Hawke Bay, and Long Beach earthquakes, all of 10–12 km. focal depth, at the geophysics department at Saint Louis University, Saint Louis, Missouri, under the direction of James B. Macelwane, S.J..

[edit] References

1. ^ Cornelius G. Dahm (January 1936), "Velocity of P waves in the earth calculated from the Macelwane P curve, 1933", Bulletin of the Seismological Society of America 26 no. 1; p. 1-11

Filll, as you undoubtedly know, there is a difference between all of science and new science. It is quite telling that physicists tend to gravitate to whatever is new, and to leave the rest for those who wish to follow. It's like the development of the transistor; they were physicists in large part; the person who brought transistor technology to Sony/Japan was -- a geophysicist; one of the pair who discovered the structure of DNA was -- a converted physicist; the World Web Web was invented -- at CERN, not to mention arXiv.org. What is common to all of this is a wide-open viewpoint and the willingness to go the extra distance to the new knowledge, whereever it lies. But it can be a hard road. This hardship might also be noted in the article.

MIght I create a formal section for the nomination of a moderator? --Ancheta Wis 00:32, 26 January 2007 (UTC)

Category:seismology

There is no formal definition of physics; many people have their own definitions in order to satisfy their specific requirement. Some definitions of physics include:

1. A practical description of the remit
2. One that gives you a feel for the subject
3. A more rigourous definition of physics, however, is
4. Essential, informative, and relevant beyond the characteristics of current physics
5. Physics is a general set of principles thought to be obeyed by all known systems in nature. Practicing physicists traditionally study a limited (albeit rather broad) set of phenomena which are most amenable to direct study using the aforementioned concepts. Most notably this involves fundamental properties of matter, energy, space, and time (which are now all known to be intricately related). As human knowledge has advanced, the set of physical principles and the phenomena fruitfully studied with them have both increased, leading to active interdisciplinary fields such as biophysics and geophysics. Nonetheless direct application of the laws of physics is (currently) prohibitively difficult in many cases. Thus fields like biology, chemistry and others have their own methods and concepts which cannot be directly derived from the presumed underlying physical laws. So physics is not any study of nature; that is natural science, different fields of which have developed their own tools and language. But, importantly, should any field of science discover some phenomena which violates basic laws of physics, the laws would have to be modified in order to retain their general, encompassing stature. Finally, this article is for the general reader, not an expert, and should be written so. Joshua Davis 04:46, 26 November 2006 (UTC)

[edit] Position D

1. Rutherford's Definition

[D] Ernest Rutherford in J. B. Birks Rutherford at Manchester (1962)

8 words.

84 word paraphrase: Science is not merely a collection of facts, but more importantly, a consistent, coherent structure of interconnected results which follow scientific method.

At the time Rutherford spoke, only physics could claim this position. Anything else became a series of ad-hoc positions (stamp collecting: matter, energy, atoms, penguins). Biology had not yet discovered the structure of DNA; the atoms of chemistry had not yet been explained by quantum mechanics. Progress has come by using the constructs of physics.

Confer with Joshua Davis' statement included in #Position B.

[edit] Position E

1. Einstein's Definition

39 words - [E] Albert Einstein (1936), Physics and Reality, summarized in his Essays in Physics (1950) New York, Philosophical Library p. 51

Confer with Noetica's and Krea's statements above. I do not have a copy of Einstein's Ideas and Opinions which actually dovetail with Position B above. --Ancheta Wis 01:56, 25 November 2006 (UTC)

48 words. [E2] Albert Einstein (1918, Max Planck's 60th birthday) "Principles of Research" in Ideas and Opinions, ISBN 0-517-55601-4 (1954) p.226. --Ancheta Wis 08:24, 29 November 2006 (UTC)

Space or distance, length

Time or duration

Mass or measure of matter

Charge a property of matter

Frequency Feynman 1 2-5 Units of Hertz, or oscillation/sec

Energy

Temperature

Entropy

Well, what does physics have that no other science does?

1. Sets of well-known equations, some with centuries of use. A community of researchers who know what to do with them. Sets of industries which have applied them. Chemistry and Biology are slowly coming on-line with computational chemistry, etc
2. Some history of investigation: some of the data has been accumulated over millennia. Now biology especially has an analog of this with species with billions of years of evolution in their genetic code, and with primates, with species perhaps 10 million years old, with their super-fast visual processing. So the species can be viewed as a database of DNA investigation of a hostile Earth.
3. A philosophical base. Sorry Joshua if that seems too pro-philosophical.
4. A community of technologists in symbiosis with the science. This is a clear advantage over the biologists, who currently do not produce artificial life. or artificial brains.
5. A symbiosis with mathematics.
6. A history of community with like-minded researchers. This does not excuse the obverse, such as hostility to researchers like Ludwig Boltzmann
7. Strong foundation in scientific method. Other sciences such as biology have not undergone the reductionist revolutions.

Well, Krea, the past weeks have served to solidify a proposed definition. It has some distinct positions in it, but the other versions do as well:

• Physics can be defined as that science which seeks those fundamental laws to which the universe is subject.

Now fundamental refers to those equations which can be expressed as differential equations, typically in an inertial frame, but with respect to some well-defined transformation law, defined by the symmetries of the system under discussion.

Let's please not dismiss the concepts behind systems far from equilibrium. They need not be biological. What if this discussion were encapsulated for the future. --Ancheta Wis 01:17, 17 October 2006 (UTC)

Krea, I have a small definition for you:

• A physicist is someone who discovers a law of nature.

Now that could include a lot of people, if they knew nothing beforehand. So one would have to qualify it to make it more conventional and sharper

• A physicist is someone who discovers a new law of nature.

In other words, physicist is a badge of honor, in my book. A child who understands something on her own, and does right by it, has accomplished something.

M, It is not shameful not to have attained the title. If you want to accomplish something noteworthy, how about starting here and now. Work with us, by helping us converge on a suitable definition.

There is no choice. Noetica's idea of Ecumenism and pluralism are the only visible route out of this labyrinth of words. Might we heed the words of Galileo, the physicist, quoted above, and listen to the message that Nature is speaking to us, loud and clear, right now.

SFC9394, if we consider the productivity of this page, might I suggest that something be restructured. It is not right that we continue in this fashion. We need something else. Failing that, we should remove the note at the top of the Physics article, perhaps leaving it on the talk page, with a slightly more modest font and box size, in keeping with the accomplishments so far.

This effort of definition has re-hashed things over 3 times. Since some of us appear to specialize in commentary, perhaps we might present less the of type of argumentation that diverts and diverges, at a time when we are trying to converge. Might I request that we take such commentary 'under advisement', during definition phase. There is nothing wrong with any of the arguments on the page above. But the timing of the contributions is wrong, if the article is to be developed in the specified sequence.

This page appears to be re-creating Nupedia in miniature. In other words, it is wasting a lot of people's time. But strident insistence on 'Physics is x, y, and z' is uncomfortably close to the arguments about the four humors of the western ancients. Now how would that look to anyone in the future? How would anyone who then believed in the five essences of Chinese civilization accept such categorical statements? How would any progress get made in any kind of science? Answer: by reconciling conflict. Perhaps by reaching common ground. May I ask us all to avoid Wikipedia:Tendentious editing and place your comments in the context of the article's current phase and stage of development.

As an aside, what would be wrong with Newton's method as applied to article definition; in other words, give up the insistence on strict sequential development, and simply let the editors work on the wip page directly?

Krea, there appears to be an analogy to a reactor vessel here: the Pressure, Temperature, Volume, Mixing ratio, and chemical population are currently not producing the expected chemical reaction. M points out that 3 editors are insufficent. At Wikimania, User:fuzheado noted that the number needs to be about 35 for satisfactory pages. --Ancheta Wis 00:44, 3 November 2006 (UTC)

[edit] Thermodynamics and the paradox of irreversibility

Main article: arrow of time

By 1798, Benjamin Thompson (1753-1814) had discovered that work could be transformed to heat without limit - a precursor of the conservation of energy or

• 1st law of thermodynamics

In 1824 Sadi Carnot (1796-1832) scientifically analyzed the steam engines with his Carnot cycle, an abstract engine. Rudolf Clausius (1822–1888) noted a measure of disorder, or entropy, which affects the continually decreasing amount of free energy which is available to a Carnot engine in the:

• 2nd law of thermodynamics

Thus the continual march of a thermodynamic system, from lesser to greater entropy, at any given temperature, defines an arrow of time. In particular, Stephen Hawking identifies three arrows of time^[1]:

• Psychological arrow of time - our perception of an inexorable flow.
• Thermodynamic arrow of time - distinguished by the growth of entropy.
• Cosmological arrow of time - distinguished by the expansion of the universe.

Entropy is maximum in an isolated thermodynamic system, and increases. In contrast, Erwin Schrödinger (1887–1961) pointed out that life depends on a "negative entropy flow"^[2]. Ilya Prigogine (1917–2003) stated that other thermodynamic systems which, like life, are also far from equilibrium, can also exhibit stable spatio-temporal structures. Soon afterward, the Belousov-Zhabotinsky reactions ^[3] were reported, which demonstrate oscillating colors in a chemical solution^[4]. These nonequilibrium thermodynamic branches reach a bifurcation point, which is unstable, and another thermodynamic branch becomes stable in its stead^[5]. "Suppose that we have a chemical reaction {A} ↔ {X} ↔ {F} in which {A} is a set of initial products, {X} is a set of intermediate products, {F} is a set of final products. At equilibrium, we have a detailed balance where there are as many transitions from {A} → {X} as from {X} → {A}, with the same applying to {X} and {F}. the ratio {A}/{F} takes on a well-defined value if the system is isolated. Now consider an open system. There are many solutions for {X} for given {A} and {F}, but only one corresponds to maximum entropy. This solution, which we call the "thermodynamic branch" may be extended to the domain of nonequilibrium, but that this branch becomes unstable at some critical distance from equilibrium. The point at which this occurs is known as the bifurcation point. Beyond the bifurcation point, a set of new phenomena arises"^[6].

Instrumentalism takes the view that a scientific theory is only as good as its predictions. Furthermore, the explanatory power of that theory is immaterial. Deutsch deplores this view.^[7]. Rather, Deutsch hypothesizes a multiverse of spacetimes; that space be a series of snapshots at a moment in the universe and time be a sequence of moments which index those snapshots^[8]. But that sequence of moments is known in principle only beginning from the Planck epoch, 5*10^-43 seconds 'after' the Big Bang, which occurred an infinity of cosmological decades before it. This viewpoint is a consequence of general relativity: there are an infinity of worlds and an infinity of moments.

Einstein would not have accepted Deutsch' viewpoint. Rather, Einstein accepted only the single static universe, and modified the Einstein field equations to reflect this. But in 1927, Georges LeMaître argued, on the basis of general relativity, that the universe originated in a primordial explosion. At the fifth Solvay conference, that year, Einstein brushed him off with "Vos calculs sont corrects, mais votre physique est abominable"^[9]. In 1929, Hubble announced his discovery of the expanding universe.

Image:COBE cmb fluctuations.gif p252

"Near the beginning (or end) of the universe, everything would be squeezed into an exotic state that mixes up the dimensions of "space" and "time". [At] ... the Planck time there is then a firm barrier. On this tiny scale, some theories, going back to Wheeler's pioneering ideas in the 1950s, suggest that the time dimension was intermingled with the three spatial dimensions into a froth of "space-time foam"."^[10] "Penrose thinks times arrow is orientated by the difference between the dynamics of the big bang and the big crunch."^[11] But note this does not account for hyperinflation. Penrose's twistors - space and time are composed of interlaced light cones. p265

1. ^ pp. 182-195. Stephen Hawking 1996. The Illustrated Brief History of Time: updated and expanded edition ISBN 0-553-10374-1
2. ^ Erwin Schrödinger (1945) What is Life?
3. ^ G. Nicolis and I. Prigogine (1989), Exploring Complexity
4. ^ R. Kapral and K. Showalter, eds. (1995), Chemical Waves and Patterns
5. ^ Ilya Prigogine (1996) The End of Certainty pp. 63-71
6. ^ Ilya Prigogine (1996) The End of Certainty pp. 65-66
7. ^ David Deutsch (1997), The Fabric of Reality ISBN 0-7139-9061-9, p. 3
8. ^ Deutsch, p. 285
9. ^ John C. Mather and John Boslough (1996), The Very First Light ISBN 0-465-01575-1 p.41.
10. ^ Martin Rees (1997), Before the Beginning ISBN 0-201-15142-1 p.210
11. ^ Martin Rees p.216

Monkey Forest is a Hindu temple in Bali. The temple is an open-air forest, symbolizing birth (at the lowest level), middle life (at the entrance), and death (at the highest level on the top of the mountain)

JDoorjam, My nominations are also meant as test cases, made in good faith. In each case, I selected an article with well-known noncontroversial content. I have professional (or personal experience in one of the articles) in each of the articles I selected and personally believe they are all good articles, from the Space Program, from Electronics, from Physics, from History.

Several of the articles are authoritative. One of them is unmatched on the entire internet (because it was written by multiple minds, all cooperating, which is peculiar to the Wiki). They are not all universally labelled Good Articles due to conflict-of-interest if I were to so label them. (For example, I am an alumnus of pioneering companies in several of those fields, and have left out some good stuff because that would amount to publication. My co-workers worked personally on one of the subjects; that content got in some of the articles, due to what I learned and understood from those co-workers.)

What is revealing is that the nominations received a passionate response even though a protocol was clearly indicated in the process, and that personality was not supposed to be a variable. To the other editors with stakes in the articles, I apologize if this puts the articles in the spotlight, but they are strong enough to stand on their own in any venue. For example, some of the material in the articles I learned from a founder of the subject (pardon my French) and it would have taken decades for another editor to match that.

My personal motivation for supporting Gmaxwell's idea is that several of my articles were actually Featured Articles, but lost that status because of the unbridled edits, which at least could have been contained if such a mechanism had previously existed. So I am interested in seeing work not go down the drain; I have been forced to cut down on my watchlist because of the volume of changes.

You appear to have at least one Featured Article and I believe you would empathize with the effect of attrition on these articles. If the articles had a chance of being stable I could then watch more of them. --Ancheta Wis 00:39, 13 July 2006 (UTC)

2,406,885 articles as of 09:36 (UTC) Tuesday, June 10, 2008 New pages showing that at 07:19, August 4, 2005 (UTC), the 666 666th article was either James Robson (from the Oz (television series)) or Jason Goes To Hell: The Final Friday

[edit] T

1. Definition -- See list of topics to the right, or see the categories

1.1 Originally, physics (from the Greek, φύσις (phúsis), "nature" and φυσική (phusiké), "knowledge of nature") was the science of nature^{[1] [2]}.

1.2 Over the course of twenty-five hundred years, physics has become known for a series of fundamental laws^[3]. Called natural philosophy^{[4] [5]}, physics was the science for identifying the constituents of the natural world^[6].

1.2.1 The role of energy was identified by the eighteenth century, and precisely defined by the nineteenth century.

1.2.2 The atom^[7] of matter was successfully subsumed into the infrastructure of the sciences, which are indebted to physics. During this time, science became professionalized and specialized; physical explanations for various complex systems were formulated, for chemistry^[8], for biology^[9],^[10], and more recently for neuroscience^[11].

1.2.2.1 Now that E=mc² has publicized the equivalence of matter and energy, any definition of the mass noun "matter" must also state the energy levels involved in that physical system, for matter can be created or destroyed, at the cost of that energy.

1.2.3 The role of information, or negative entropy in a open system was first recognized in physics in the late nineteenth century and explicated in the twentieth century, with expression in engineering hardware, software agents, and in biological systems, in our time.

1.3 It is difficult to state a prospective or even current definition for physics, for each researchers' focus defines their subject of study. Thus we can talk retrospectively of Galileo's physics or Einstein's physics, but we cannot talk of a current researcher's physics, or a future researcher's physics without determining their philosophy^{[12] [13]} . For example, Murray Gell-Mann's contribution to complex systems should be noted^[14].

1.3.0.1 In an aggregate definition of physics, such as in a list of items (in the TOC at right), the items serve to name something which is incompressible, which cannot be further reduced, such as the Greek concept of the atom of matter. This was Newton's conception of matter. But physics has discovered energy regimes where atoms have parts, and the definition of fundamental can then be questioned, for the energy regime must also be stated for such a definition to hold, whether it be room temperature or 10³² kelvin at the instant of the big bang.

1.3.0.2 But an aggregate need not have tensile strength; then the slightest pull would separate the components. Thus a proper definition of physics should also include a unifying agent, to bind it into a subject.

1.3.0.3 One candidate for that unifier is Nature itself. Nature, to man, seems welcoming, our home, the source of our life. But overall, the universe is hostile to life and to us. Indeed, life itself is a huge competition of life-forms for their individual advantage. And Nature, with its enormous powers, can be hostile to us as well. Thus we cooperate in symbiosis to survive it.

1.3.0.3.1 Earth is part of that Nature which holds us. But Earth is built largely from iron, an ash of stellar nucleosynthesis in the burning of the stars; thus our earth is composed of stellar ash, and we were made from the stars, because gravitation kept the elements from which we were made on this planet. The lighter elements which we breathe are kept here by virtue of gravitation. One of the problems in the exercise books of the Feynman Lectures on Physics asks "what is the probability that we have drunk from the water which our forebears drank?" and the answer depends on your philosophy.

1.3.1 Physics itself is further developing, both inward (beyond the atomic nucleus, which requires the use of ever-higher energy regimes) and outward (by consideration of the circumstances for big bangs and the development of our own universe from the multiplicity of multiverses which could have been ours). But the two realms are currently not unified under one theory.

Physics need not be considered an arcane or difficult subject. Classical mechanics can be amply illustrated on children's playground equipment or in a sports stadium. Read on for more --

Note to the reader: You may, without loss of generality, skip any point marked by a bullet below, e.g.

• This denotes a detail.
• "Truth is ever to be found in the simplicity, and not in the multiplicity and confusion of things." —Isaac Newton
• "To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, and leave the rest for others that come after you, than to explain all things." —Isaac Newton

2. Introduction

Physics can explain the system of the world An example of the system of the world: -- looking to the west, clouds are moving toward us, in an illustration of the rotation of the Earth. The clouds are part of an atmosphere with a uniform temperature across the sky at a single altitude, but with temperature which varies with altitude. The clouds have condensed from vapor to water droplet at a precise temperature, uniformly, thus causing a flat-bottomed cloud. The air is not mixing at these altitudes, which we see as a straight line, parallel to the horizon. Thus gravitation is influencing the shape of the flat-bottomed clouds. At other locations in the sky, the clouds are subject to turbulence and mixing. The density of the atmosphere also is varying with altitude, causing a continuum of hue, with deeper blue at the zenith and lighter blue at the horizon (obscured by the trees). The blue color of the sky is due to Rayleigh scattering, which also explains the red color of the sunsets (not shown). Characterization: the Nature of things The basic program for physics was instituted most noticeably by the time of the scientific revolution. In this program, a 'system of the world' was demonstrated by Newton[15], by which ever simpler constructs could be examined. This was the basis for several revolutions over the succeeding centuries during which physics became more and more exact and also more and more abstract. The program for mechanics, instituted by Newton, basically answered 'where' and 'when'[16]. This was the triumph of the geometrization of mechanics begun by Galileo. Characterization of successive elements of nature then proceeded as physics developed. This parabola-shaped lava flow illustrates Galileo's law of falling bodies as well as blackbody radiation -- you can tell the temperature from the color of the blackbody. Cassiopeia A - a spherically symmetric remnant of the 1680 supernova The Astronaut and Earth are both in free-fall. Diffraction of light by a prism. Lightning is electric current. Experiment. Historically, physics has developed hand-in-hand with technology; the experimental devices of the scientists of each era had features which were consistent with the physics of that time. For example, Walter Bothe built the AND gate for a coincidence detector for use in Compton scattering. For this work he got the Nobel prize, 30 years later, in 1954. Today, Boolean logic is routinely used in engineering and information technology. Galileo built his own telescope (but not the lenses) - philosopher Baruch Spinoza was a lens grinder. Isaac Newton, accounted the greatest physicist in history, built his own telescopes by grinding his own mirrors with pitch (from which we routinely use Newton's rings to judge the quality of a telescope's mirror), and performed his own optical and alchemical experiments. The following list of technology which has been used in experiments can serve as a chronicle for the history of experimentation, as applied in an experiment (sorted by date of invention) 4500 BCE - the astronomical observatory is ancient enough for observations in India to document the precession of the constellations, 2700 BCE - a simple machine - the inclined plane - used by Galileo to determine the acceleration of gravity in the early 1600s, 2000 BCE - mirrors were exploited by Isaac Newton to minimize the abberation in the telescope in the 1670s, 600 BCE - Archimedes' screw, imaginative use of the simple machines 300 BCE - the pump was used by Otto von Guericke to produce a vacuum in 1654, 200 BCE - the astrolabe was used in navigation, 80 BCE - the gear was used in the engine, 975 - the pendulum was used by Galileo to measure time, 1280 - the lens was used to build telescopes, 1600 - the telescope was used by Ole Rømer to measure the speed of light by observing the motion of Io across Jupiter, 1680 - a prism was used by Newton to determine a theory of light, 1700 - the bell jar was used to study vacuum and the atmosphere, 1745 - the Leyden jar was used to store electrical charge, 1761 - the chronometer was used to measure time at sea, 1824 - the engine was used to provide energy and do work, 1821 - a railroad car was crucial for the development of relativity, 1860 - the spectroscope was to be used in quantum theory, 1903 - the airplane has been used to measure the cosmic microwave background, 1906 - the vacuum tube was used as an electrical circuit element, 1924 - Walter Bothe builds the AND gate, an electrical circuit element, as a coincidence detector for use in Compton scattering in 1924, 1929 - the cyclotron was used to accelerate charged particles, 1935 - the magnetron was built as a source of microwave radiation (suitable for radio frequency direction finding and a crucial element of the technology disclosed by the British to the Americans on the eve of WWII), 1945 - the digital computer was used to solve equations, 1947 - the transistor was used as a circuit element, 1957 - Isaac Newton proposed a thought experiment for a artificial satellite as part of his demonstration of the free-fall of the planets (1687), 1959 - the integrated circuit could miniaturize and commoditize circuits, 1960 - the laser was built as a source of photons, 1969 - the internet could commoditize knowledge, giving rise to the world wide web and to systems based on trust, 1978 - the global positioning system of artificial satellites could commoditize the determination of position and time, 1986 - the atomic force microscope could manipulate atoms, 1999 - NIST-F1 could serve as a time standard 2006 - People discover they can walk upon a swimming pool filled with a non-newtonian fluid. (This could also be dangerous - don't do this at home.) 2006 - John Cramer is preparing an experiment to determine whether quantum entanglement is also nonlocal in time as it is in space. This can also be stated as 'sending a signal back in time'. The experiment is still in preparation as of 10:57, 16 November 2006 (UTC). more... Image:Archimedes' screw.jpg Archimedes' screw uses the simple machines to lift water. The hands-on experience with the devices of technology is an essential part of physics. Richard Feynman, blunt-spoken and not known for diplomacy, once remarked that the 1930's era cyclotron at MIT was hand-built and well-used, while the cyclotron at Princeton, was more professionally built, and therefore little-used during his term of study there. Forty years later, building cyclotrons was a high-school level activity, which can cause signficant drain on the electrical grid of the neighborhood. Physicists have used the technology of each era to further their own scientific predictions, as well as to further the development of mathematics, in each era, in a cooperative effort. Mathematical notation is the writing system of mathematics, a technology to which physicists have contributed and in which the theories of physics are often expressed. In physics, however, the constructs of physics are paramount in the use of any notation, liberally interspersed with visual diagrams of the physical situation. It has been the custom to retain a standard set of symbols when writing in a mathematical notation, which allows a 'feel' for the subject and permits common representations of the same things. And physicists learn mnemonics (see right-hand rule) and other informal representations (such as those which show how to multiply matrices, or how a dimension might be rolled-up) as well. "3 candlesticks times 5 cab-drivers is 15 candlestick cab-drivers" -- George Gamow Physics series: Physicists Archimedes Eratosthenes Gilbert Galileo Newton Lagrange Hamilton Faraday Maxwell Boltzmann Gibbs Planck Einstein Bohr Dirac more... Physics Portal Theory. The current constructs of physics include space, time, mass, charge, energy, fields, entropy, information, the parameters of the standard model. Step by step, the constructs took basic mathematical models of physicists -- Galileo, Newton, Lagrange, Hamilton, Faraday, Maxwell, Boltzmann, Gibbs, Planck, Einstein, Bohr, Dirac, and others and applied them with ever greater precision. The interplay between theory and the real world (as experimentalists like to say) has been fruitful for physics: new physical phenomena can serve as challenges to theoreticians to be explained in their theories because that theory is incomplete, or to show that a hypothesis has been disproved and the theoretician must select another realm of possibility, or a theory has been corroborated -- and the theory is not yet disproven. The thought experiment need not be expensive, but the people who are able to create them are required, for their publication. (See TOC, right) One technique used in physics research involves Carnap-Ramsey sentences. The free and bold construction of mental models has existed from the inception of the science of physics; this technique shows specifically how to side-step questions of ontology by focusing on the gist rather on potentially irrelevant detail: "every time a theoretical term appears in a theory one should substitute a variable x for it and the theory should be preceded by the expression 'there exists a certain thing x, such that ... '"[17]. For example, a brane can be fruitfully applied in this way, without worry whether branes 'exist' -- thus Henry Tye can theorize that the Big Bang was produced by the collision of a brane and its anti-brane, which is a statement that would apply before the emergence of spacetime. This free mode of thought can be used, for example to solve any differential equation (as Feynman liked to put it[18]), but it requires imagination. Today, even the most basic concepts such as space and time are known to their theoretical limits; in physics we can even conceive of a smallest space and a smallest time which are known to be nonzero. Today, experimentation has progressed to the point that single atoms can be imaged in their positions in materials, and single atoms can be positioned at will, where earlier physicists from two thousand years before could only speculate on the existence of atoms on the grounds of ontology. Although it takes enormous amounts of energy (i.e., money), particles can even be artificially created or destroyed. But the mass points of Newton are now the target for even closer scrutiny and require the consideration of stupefyingly high-energy realms which we cannot investigate experimentally on Earth, leaving us only the cosmos as our laboratory for particle physics. What are under investigation are basic properties of the Standard Model and the symmetry exposed by the model. The process of development in physics continues to this day, with no limits in sight. Categories of physics [–] Physics [+] Applied and interdisciplinary physics [+] Atomic, molecular, and optical physics [+] Physics awards [+] Computational physics [+] Condensed matter physics [+] Physics education [+] Electromagnetism [+] Physics events [+] Experimental physics [+] Fringe physics [+] Fundamental physics concepts [+] Gravitation [+] History of physics [+] Introductory physics [+] Levitation [+] Physics lists [+] Physics literature [+] Mechanics [+] Physics organizations [+] Particle physics [+] Philosophy of physics [+] Physical property [+] Physical quantity [+] Physical systems [+] Physicists [+] Plasma physics [+] Pseudophysics [+] Physics societies [+] Statistical mechanics [+] Theoretical physics [+] Thermodynamics [+] Turbulence [+] Unsolved problems in physics [+] Vortices [+] Wikipedia requested photographs of physics subjects [+] Physics stubs

Prerequisites
scientific notation
natural units
algebra
geometry
vector notation
optics
operators
differential equations
partial differential equations
mechanical engineering
electrical engineering
probability
statistics
Venn diagram for Physics Diagram by User:David R. Ingham.

3. History & Foundations

4. Principles/Concepts

5. Current Topics/Current Research

6. Applications and Influence

7. References and Notes

1. ^ "Greek Physics", in "Physical Sciences, History of" Encyclopædia Britannica, 15th ed.
2. ^ Nature also has the meaning of characterization, which was Homer's first recorded use.
3. ^ "Physical Theories, Mathematical Aspects of", Encyclopædia Britannica, 15th ed.
4. ^ The definitive work is Newton's The Mathematical Principles of Natural Philosophy, in Latin Philosophiae Naturalis Principia Mathematica
5. ^ Doctorates in the sciences are often Doctor of Philosophy, abbreviated Ph.D.
6. ^ "Physics", Encyclopædia Britannica, 15th ed.
7. ^ Atom is Greek ἄτομος or átomos meaning "uncuttable"
8. ^ For chemistry, the periodic table of the elements can be explained directly by quantum mechanics
9. ^ For biology, the discovery of the structure of DNA was made by concrete modelling, based on x-ray diffraction experiments. Based on this result, Francis Crick immediately noted its significance for the explanation of life.
10. ^ Before the 1800s, physic also referred to physiology, as evidenced by the term physician for medical clinicians.
11. ^ For neuroscience, the time-sequenced operation of the visual system is predicated on the action of mirror neurons, which anticipate actions of the subjects in view. Jeff Hawkins predicted "enhanced neural activity in anticipation of a sensory event" one year (2004) before experimental confirmation (2005) by Giacomo Rizzolatti, Leonardo Fogassi, Vittorio Galles. "Mirrors in the Mind", Scientific American November 2006, pp.54-61.
12. ^ G. Toraldo di Francia (1976), The Investigation of the Physical World ISBN 0-521-29925-X p.6
13. ^ Stanislaw Ulam noted that the physicists he encountered during the Manhattan Project were not exactly anti-intellectual, but rather, anti-philosophical. See: Stanisław Ulam, Adventures of a Mathematician, New York, Charles Scribner's Sons, 1983 (autobiography)
14. ^ This was motivated in part by Gell-Mann's commitment to preserving the natural world
15. ^ Newton (1687) Philosophiae Naturalis Principia Mathematica
16. ^ Richard Feynman (1963) The Feynman Lectures on Physics 1 p.5-1.
17. ^ G. Toraldo di Francia (1976), The Investigation of the Physical World ISBN 0-521-29925-X p.74
18. ^ Laurie M. Brown (ed.) (2005), Feynman's [Ph.D.] Thesis: A new approach to Quantum Theory ISBN 981-256-366-0 p.13

8. External Links

Word counts:

1. Definition, not including the citations or italicized words -- 312 words

1.3.0.x -- 150 words

Further development from a tutorial point of view might place the physics of the playground (i.e., classical mechanics) under section 3 or section 4 depending on consensus.

Interrelationships of the topics of physics might go in section 3 or section 4 depending on consensus.

Some of the contributions to complex systems by Murray Gell-Mann and others might be placed in section 5.

It would be a shame not to highlight David R. Ingham's venn diagram for physics.

[edit] T

1. Bayesian inference
2. Cosmological decade
3. Covariant derivative
4. Diabetes management
5. Diabetes mellitus
6. Double negative
7. Eigenface
8. Electrical resistance
9. Franklin Mountains
10. Gravitation
11. Great Books of the Western World
12. Ground (electricity)
13. Heuristic
14. History of computing hardware
15. History of science
16. How to Solve It
17. Hughes Aircraft
18. Integrated circuit
19. Kilbourne Hole
20. King Ranch
21. Law of physics
22. Malay people
23. Mathematical notation
24. Maxwell's equations
25. Mist Trail
26. Model
27. Negrito
28. Noether's theorem
29. On Intelligence
30. Physical constant
31. Portal/Geography/Intro
32. Principia Mathematica
33. Probability amplitude
34. Process
35. Pueblo people
36. Quantum mechanics
37. Ralph Bunche
38. Recognition
39. Richard Feynman
40. Scales of measurement
41. Scientific method
42. Semiconductor fabrication
43. Task
44. Test
45. Thinking
46. Truth
47. Validity
48. Visual system
49. Wisdom

It appears that the theses of Petrarch and Gibbon, who witnessed shepherds grazing their flocks among the ruins of Rome is under attack. Thus a Roman-centered view of the development of western civilization is POV. Fine. The counter-argument appears to be that the medieval universities were the truth-bearers. They started the infrastructure which we need for scientific communities; these universities produced thinkers like Robert Grosseteste (1175 - 1253), Roger Bacon (1214 – 1294), Albertus Magnus (1193-1280), Duns Scotus (1266 – 1308), William of Ockham (1285–1349), and Jean Buridan (1300 - 1358) . Thus the disputed sentence might be replaced with

The regression in knowledge began to abate as early as the twelfth century. By this time, the universities of Europe aided materially in the propagation, translation and preservation of the texts of the ancients, including Archimedes, Eratosthenes, Hipparchus, Aristarchus, and Euclid. By the thirteenth century, these texts began to be extended by thinkers such as Robert Grosseteste, Roger Bacon, Albertus Magnus, Duns Scotus, William of Ockham and Jean Buridan. In particular, the empirical approach admired by Roger Bacon was exemplified by Petrus Peregrinus.

One rule of thumb for the field: "Do you like to play computer games?" If you can say "yes" and you consistently beat everyone you play against, for example, you probably have the mental agility needed to be good in the CS field. No math required because you would pick up what you really need quickly. But don't be discouraged if it seems to take a while. Like any tech subject, it will take years to gain proficiency. Then your problem will be convincing someone you can do the work. But if you make your name in the Open Source field, where there are no barriers to entry except your own skill, then the field is wide open, and you will get a job because your programming skill will be apparent to everyone in Open Source. I would discourage you from the Gaming software field, however. Only fanatics succeed there; you have to work ridiculously long hours for low pay in that field. (But at least you get to work on the finest hardware.) Ancheta Wis 22:02, 21 October 2005 (UTC)

After years of chasing craigslist.org, our website has managed to cross places with the classified ads provider, as Alexa shows that today we are now at #31 in the world vs #34 for craigslist. Will the trend continue? Is this for today only? Their weekly average is 32 and ours is 34. But who's counting? Might this be a variant of editcountitis? And the blind test has shown that the category bar has no correlation with the rise; the only way to prove there is a correlation with the #31 is to remove the browsebar. Ancheta Wis 22:18, 20 October 2005 (UTC)

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[edit] Truth

Everyone, I appreciate your sincere contributions; we are not in a race. That means giving each other space, eh? No one is trying to get anyone else. We are trying to contribute in good faith. It's no good to be 'true and valid' if the article fails the tenets of the encyclopedia. One of the side-effects of a community is that we get to know how someone else will act in a situation; we get to know each other's character. Then, actions of praise and kindness from mutually respected people can resonate.

Here is an example - in face-to-face conversation, we might look at each other's faces to see how our statements are being received. We don't just keep talking.

In the same way, when declaiming a proposition, we attempt to reach our audience, we don't just write and write. We wait for feedback. So, if someone writes 'a', and then 'A' and then A, etc. continually escalating, then what is the point? There must be another agenda in operation. If it becomes clear that the article is not on that agenda, but rather a form of competition, then we ought to call a 'time out'.

Is it clear that our 'behavior' is what is under review? I hope so.

Perhaps we might just give the article a rest for a while. In the meantime, I have found some vandalism which seems to have escaped our notice while the disputes are echoing.

This is a simple enough beginning and a start. But generally, in an introduction, we set the stage. That is, we give context before we state content. Are we agreed that the context of this term is philosophical? If not, might there be a manifold context, namely the psychological, ethical, practical, theological, and spiritual views, as well as philosophical? If so, where is the discussion of the more fundamental context? What article contains this more fundamental view? Is this the very article which must contain that view? In other words, where is the ontology for this article? Simply dealing with true as a predicate with value 1, doesn't say half of it; there is more to the meaning. The connotation for truth is that someone has thought about it, and that others can reliably depend upon it. It appears there are manifold views of truth. If we were to view truth as a jewel, and the different angles from which we view that jewel as "views of truth", then the nature of truth can be called unitary.

I am not trying to stir up trouble. My personal use of this article is as a foundation article for my own interests. As a user, truth is something I depend upon. I happily defer to those who can speak about it. Ancheta Wis 15:10, 24 September 2005 (UTC)

One difficulty is that people see through eyes that are culturebound. Another is that myth does not depend on truth as a basis for action. What is obvious to one person is completely obscure to another. Even worse, a society may ban someone whose values and culture do not coincide with the cultural norms of that society. Thus we have social islands of value and culture, which may or may not be able to bridge the gaps between them and other islands of value and culture. If philosophy is attempting to define those values which aspire to be global, if not universal applicability, then truth is a place to start. Ancheta Wis 19:00, 25 September 2005 (UTC)

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1. a scientific community is part of the ecosystem of science. See history of science for detail.
2. Hewitt and Kornfeld used a model for this process, as part of their research on actor and planner. This work was done years before the World Wide Web.
3. Hewitt retired and had time to contribute to the encyclopedia.
4. The rules for editors who are both researchers and original contributors had not been completely written out, at the time of the contributions.
5. As the contributions and the rules have unfolded, a researcher is currently not allowed to place his original result in the encyclopedia, as this is defined as "self-promotion". One is not currently allowed to place references to one's one work in the encyclopedia, although this is allowed in academia.
6. The role of an expert in the encyclopedia is both desired and denied at the current time. 12:27, 24 September 2006 (UTC)
7. Result = No consensus. Hope this helps. --Ancheta Wis 12:27, 24 September 2006 (UTC)