# Talk:Theoretical physics

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## Einstein

The Michelson-Morley experiment disproved the existence of an ether before SR. The first paragraph's ending might be implying otherwise, as it is being stretched to make a point. (better example?)

-About the sentence "Sometimes it is the vision of mathematicians which provides the clue; e.g., the notion, due to Riemann and others, that space itself might be curved," doesn't this imply that Einstein got the "clue" of the "curvedness" of spacetime from Riemann and others? I don't think this is correct. -Ur

Also, I think the sentence "For example, while developing special relativity, Albert Einstein was concerned with the Lorentz transformation which left Maxwell's equations invariant, but was apparently uninterested in the Michelson-Morley experiment on Earth's drift through a luminiferous ether." is not a good example to "mathematical rigor." Einstein was following his physical intuition as to how the theory ought to behave, which certainly did not stem from any mathematical rigor. I think this sentence should be changed or reworded. I suggest a different example, perhaps from the work of Dirac, be given. 71.103.0.107 (talk) 08:31, 12 June 2008 (UTC)Ur

There are two theories on the physics page that are not on the theoretical physics page: Time Cube and Variable Speed of Light. I have not read much on physics so I dunno how accurate the lists are in general. But they seem to be inconsistent enough to warrant changing.

Brianjd 06:01, 2004 Jun 16 (UTC)

Time Cube is semantic gobbledegook, not a physical theory. Variable c, or c-decay warrants addition though. lysdexia 01:21, 17 Oct 2004 (UTC)

Additionally, String theory is both in Mainstream theories and Proposed theories list - one of the copied should probably be removed? As the Problems section on String threory page says "In this sense, string theory is still in a "larval stage": it is properly a mathematical theory but is not yet a physical theory" - so Proposed theories is probably the best section for it?

This page seems way too oriented to the debate involving crack pot theories. I really can't see a good reason for the Theoretical Physics page to be dominated by the sections "Mainstream theories", "Proposed Theories", and "Fringe Theories". 140.180.149.219 01:38, 18 May 2007 (UTC)

I say string theory should be removed from the mainstream theories list. Although it is "mainstream" in that it is widely accepted by string theorists (some of whom are very respectable physicists), it's not mainstream as defined by the article. --Armaetin (talk) 08:26, 5 April 2009 (UTC)
I think dark matter and dark energy are not mainstream, but proposed theories, which have not been directly detected. This should change in the article. Ema--or (talk) 22:28, 7 September 2013 (UTC)
They are consistent with the experiment, at least currently, and are shared by the majority of researchers, so I that do not quite see your point.--Ymblanter (talk) 22:46, 7 September 2013 (UTC)

## Poincaré

Hi, I think it would be also important to name Henri Poincaré among the most famous theoretical physicists. Essentially known as a great mathematician, the fact still remains that Poincaré contributions to physics are among the most important (Lorentz transformations and the premices of the special relativity theory as one of many examples). I'm just adding his name to the list. Ok? Doublestein 09:01, 20 October 2005 (UTC)

Would it be reasonable to add Faraday too? Or is he more of an experimental physicist? The line between theoretical and experimental was much more blurry in those days. --Armaetin (talk) 08:23, 5 April 2009 (UTC)

## Boltzmann

I think that Ludwig Boltzmann must be on the list either. The founder of Kinetic theory must not be forgotten.

Karolis

Maxwell...

## Edit explanation

I removed Creation science and Intelligent design from the fringe theory listing. They are not theories in the scientific sense; further, they are not relevant to theoretical physics, the topic of this article. — Knowledge Seeker 23:16, 2 December 2005 (UTC)

They're not theories in the "scientific sense", huh? What would be more "scientific": Darwinism [we come from monkeys] or the "big bang" [something came from nothing]? —Preceding unsigned comment added by 69.60.111.5 (talkcontribs)
No, they aren't. Yes, both evolution and the big bang theory are more scientific than creation science or intelligent design. Note that this does not necessarily make them more correct, but by invoking the supernatural both theories remain outside the scope of science. Also, to clarify: the big bang theory does not propose that the Universe arose out of nothingness; rather, it proposes that that all the matter and energy of the Universe was concentrated into an extremely hot and dense state which suddenly and rapidly expanded. What occurred before this (or if before has any meaning), how the Universe came to be in such a state, and why it began expansion are not known. — Knowledge Seeker 00:00, 3 December 2005 (UTC)
Still, like all existence theories, the big bang does no account for the creation of the Universe- as you just said "how the Univese came to be...[is] not known".
Actually, the story goes that God created something from nothing, and so based on your arguments, the big bang theory makes more sense than Creationism. The problem is people don't realize they are not opposing arguments; God could have created the universe by the big bang. Once Descartes removed reason from religion, people since have had this misconception of science is the oposite of religion. — dmyers4 March 28, 2006
Sure, they aren't opposing arguments, but they take very different stances on the same issue...one says God existed and we cannot comprehend his existence. We can try to understand where God came from, but we won't be given an answer in this life. Scientists don't like not knowing, so they've taken the humanistic approach that we CAN understand where existence came from. They're wrong. Don't get me wrong, I want know where existence came from too, but we'll never know.
Darwinism isn't a physical theory anyway. Evolution is in the biological sciences. --Armaetin (talk) 08:21, 5 April 2009 (UTC)

1.Why did they consider that $\oint{Pdx}$?
P seems like a periodic function...
2.By1.,I think that was just correct with some limit of
Uncertainty Principle if P represents(ed) "Poition". I said
right? Or it obeyed U.P.?
3.Why does $\oint{Pdx}=nh$? Then we by this to solve A
(amplitude)? And however,by what theory? See please[1]

--HydrogenSu 15:49, 24 January 2006 (UTC)

## Ideas for improvement

The article clearly needs more content; I was thinking of things such as:

• Explain how theoretical physics is done.
• It's interaction with experimental physics and how a lack of experimental results can lead to many theories (some fringe) being invented to describe some aspect of physics (e.g. Superstring theory).
• How theories evolve over time to take account of experimental discoveries (link to the last point).

Just a few suggestions. Cheers. MP (talk) 17:48, 9 May 2006 (UTC)

## Freeman?

I'm as big a fan of the Half-Life games as the next guy, but does Gordon Freeman really deserve a spot on the list of prominent theoretical physicists?

--210.228.17.103 03:51, 12 June 2006 (UTC)

I don't believe he does, being in that list is almost insulting. Fieldworld 19:36, 24 March 2007 (UTC)

I've had enough of this. How many times is this user going to add him? It's just stupid.

I've removed Freeman, it's an insult to have a fictional character in a list of prominent theoretical physicists. Furthermore, in the game, the roles he plays are more of an experimental physicist. - JTS

Sorry I didn't know where to comment this but why isn't Michio Kaku in the famous theoratical physicists list? He is the co-founder of the string field theory and is one of the most widely known today. Can someone add his name please because i'm kinda new to this, Thanks. — Preceding unsigned comment added by Wullieboy919 (talkcontribs) 18:59, 1 March 2011 (UTC)

## Catergorization of theories

The categorization of theories leads something to be desired. As a professional theoretical physicist, let me weigh in briefly. The three categories that are here are fine, but there really isn't much to distinguish between "proposed" and "fringe". A decision must be made regarding what is wanted with the fringe category. There are several somewhat overlapping ways to go:

1.) Theories that are essentially discredited or baseless. This would include crackpot theories that deny quantum mechanics or relativity, i.e. contract known facts. Also, could include pseudoscience such as astrology.

2.) Things that are not manifestly illogical or contradictory of fact, but are not very well favored in a sociological sense. By this, I mean, what theoretical physicists don't work on very much but will not come down and say is just wrong. An example might be time travel; there are mathematical indications from general relativity that this is possible but not many theoretical physicists would say this is a wothwhile direction of research. A less extreme example could be Loop Quantum Gravity; most physicists who study quantum gravity favor string theory.

I suggest that "fringe" is reserved for things that are viewed as essentially discredited or baseless by the entire academic and scientific communities. So one should remove Grand Unified Theories and Loop Quantum Gravity from "fringe" since there is a sizable amount of academic work done on these two. While we're at it, remove Theory of Everything as well. With this understanding of "fringe", it may now be acceptable to add astrology.

Also, although I am a string theorist, I think I have to object to the labeling of string theory as a "Mainstream Theory". While many theoretical physicists work on it, it has yet to be accepted by the broader physics community. This is rightly so; it has yet to be experimentally verified. I would simply delete it under that heading for it already appears under "Proposed Theories".

-Joshua

If there is going to be no further discussion on the matter, I'll urge Joshua to implement some of these things. To me as well the part about the classificaiton of theories read horribly. If we can't provide an allusion to the uniqueness of the current theoretical situation(an abundance of theory, not much experiment), I see no reason for the classification of theories in this article particularly

I agree with Joshua. String theory should not be considered a mainstream theory because of its lack of experimental verification. If experimental evidence should appear, and if string theory gains acceptance from many other physicists, then it would fall under then mainstream theory category. --Armaetin (talk) 08:34, 5 April 2009 (UTC)
For the same reason dark matter and dark energy should not regarded as mainstream theories; they have yet to be experimentally confirmed and have at best observational evidence. This article to should be edited to reflect this. 92.237.25.17 (talk) 01:12, 29 October 2013 (UTC)
If smth which has got a Nobel Prize is not mainstream, what is then mainstream?--Ymblanter (talk) 03:42, 29 October 2013 (UTC)

## A question on how the word physical thoery is defined.

In the article, the word physical thoery is defined as such: A physical theory is a model of physical events and cannot be proven from basic axioms. How are the words physical events being defined? I just assumed that it ment any event that takes place with anything that is composed of matter. If it wouldn't be too much do you think you could add a definition for physcial events so to avoid confusion.

71.126.110.83 22:58, 6 May 2007 (UTC) Tom Kutzmon

## Removed two theories from the mainstream list.

I removed "Particle Cosmology" and "Broken String theory GUT" from the "mainstream theories" list. We don't have articles for either of them (so far as I can tell, the former has to do with particle physics in the very early universe; if we have it under another name, it should be added back), and as for the latter, both 'String theory' and 'Grand unified theory' are already in the 'proposed' section. grendel|khan 04:46, 21 May 2007 (UTC)

## Cut out the Half-Life crap

There is at least one user, User:IMNTU, who insists on continually vandalizing this page by adding content on Gordon Freeman, the fictional hero of Half-Life. This now includes throwing in the word "Portal"(the name of a new game connected to Half-Life) at more or less random points in the text. There may be an argument to make that the character Gordon Freeman deserves some mention, perhaps in a "Popular Culture" section or something. But one can't list him as a famous physicist since this implies that he is a real person. Further any mention of the game "Portal", particularly in the random way in which it has been done recently, is irrelevent and likely vandalism. Please refrain from adding this kind of material and other editors please keep an eye out for these bad edits. If you think you have a good reason for adding this material, please make your case on the talk page first. Joshua Davis 17:46, 30 October 2007 (UTC)

## Not derivable from axioms?

The Overview sections say that theoretical physics cannot be derived from axioms. Aren't axioms the whole point? From Axiom: "Outside logic and mathematics, the term "axiom" is used loosely for any established principle of some field." Isn't the point of theoretical physics to take accepted principles and derive results from them? The only difference between mathematics and theoretical physics is that in physics, the axioms used are based on observed physical reality.--Loodog (talk) 15:05, 9 April 2008 (UTC)

Quite. In the opening of the article it states, "theoretical physics adheres to standards of mathematical rigor while giving little weight to experiments and observations", which is a misunderstanding of what experiment and observation is. Mathematical equations are demonstrations of experiments carried out and formulated into language; similar to informal logic where premises provide the variables/context that follow to their logical conclusions. So, the idea that physics cannot be derived from axioms is an axiom itself that guides the practice of physics and thus self-defeating; a false duality. TheObserverEffect (talk) 12:48, 27 April 2011 (UTC)

## Someone edited the article

Was looking this up on google and when I got here all the article is saying is "fart".

Like what the hell?

Edit: I edited the article to the normal content of Theoretical physics —Preceding unsigned comment added by Briambo (talkcontribs) 16:25, 28 May 2008 (UTC)

## Fringe vs. Proposed: an artificial distinction?

I don't see what the difference between fringe theories and proposed theories is supposed to be, especially considering the overlap between the two on the page.--Loodog (talk) 19:20, 5 June 2008 (UTC)

## Change proposal

Hi to everyone!
I would like to propose to change in the first sentence of the wikipedia article... "natural world" in "experience".
Anyone against it?
Old:

Theoretical physics employs mathematical models and abstractions of physics in an attempt to explain experimental data taken of the natural world..

New proposal

Theoretical physics employs mathematical models and abstractions of physics in an attempt to explain experimental data taken of experience

Maurice Carbonaro (talk) 12:43, 1 December 2008 (UTC)

## Proposed modification

Hi, folks. I just stumbled upon this while trying to improve my own education (I am a retired physicist) and thought I could improve upon it. I agree with the comments about ditching categorization as the main organizational principle. I also don't think that a list of prominent theoretical physicists need be a center piece. Whoever was asking what we think ought to be in this page -- I'm with you. It would be nice to see an outline agreed to on this discussion page and then some work to fill it in and tweak it.

Before I came here to see what was up, I did a partial edit on the overview section. I will put it in below for your comments before getting "bold" (as your new editor's page suggests) and, with more work, eventually putting it live. You will no doubt see that I am a bit focused on the roles of theory and experiment (some history there...).

On my soapbox here: It seems to me that the goal of an encyclopedia is to educate, but that of course makes you have to judge a uniform level of knowledge for the reader. To be honest, the technical articles I have looked at in the Wiki sound to me like an expert talking to other experts. They are way over my head, and I am not the smartest or most knowledgeable person in the world, but I'm no slouch, either. I would think something aimed at the "intelligent non-expert" or "knowledgeable non-expert" would be most useful to everyone -- at least until you get down to details in the lower paragraphs. I don't use Wikipedia for the (small, few) areas in which I consider myself an expert!!

Back on the ground, comments would be appreciated. Thanks. Tsember (talk) 21:23, 1 September 2009 (UTC)

Theoretical physics is the scientific discipline that seeks to understand and advance fundamental physical theories. A physical theory consists of a combined conceptual and mathematical model of a physical process to produce a consistent, quantitative understanding of that phenomenon. A physical theory is fundamental when it deals with quantities that are not understood at any finer level of detail. For example, the theory of operation of an internal combustion engine is not fundamental because all of the phenomena it deals with are understood at a finer level of detail that is used to understand the engine as a whole: the mechanical strength and thermal properties of an engine piston and the process of combustion are known to derive from metallurgy and combustion chemistry, respectively. In contrast, quantum mechanics is a fundamental theory because we don't (currently) know of anything from which it can emerge. Our inability to identify and understand their underlying constituents is one reason why, unlike a valid mathematical theorem, a fundamental physical theory can never be proven to be true. If such constituents are found and a valid theory for their interactions is developed, that new theory replaces its predecessor in the ranks of fundamental theories.

The goal of a physical theory is to provide a means of understanding the operation of the real world that is both quantitatively accurately and conceptually meaningful. The validity of a physical theory depends on whether or not it agrees with all reliable experimental results, so the usefulness of a new or modified theory is initially judged by how accurately its predictions agree with experimental observations, by the amount and variety of data with which it agrees, and by its ability to match observations that have not been matched before. Its validity is also judged by its simplicity and reasonableness in the context of other accepted physical theories and by how much it adds to our overall understanding of how the universe functions. However, no matter how well a theory performs by these criteria, it is usually considered reliable only after it has been thoroughly tested, that is, after it has been used to produce new predictions which are subsequently verified by new observations. Verification requires that the difference between the theory's prediction and the observation is less then their combined uncertainties. The observation is then said to support the theory, although the strength of that support depends on the size of the combined uncertainties, as well as the likelihood that additional, unaccounted-for phenomena could affect the observation. These limitations are the other reason why no physical theory can ever be proven to be true. A physical theory cannot even be "proven" to be false, but theories that consistently fail experimental tests are, in practice, rapidly discarded.

121.209.66.49 (talk) 06:30, 5 October 2009 (UTC)

Small addition, Shouldn't brian greene be on the "Prominent theoretical physicists" list too? The work he's done with string theory and all.

## Edit request from 95.44.160.38, 10 June 2010

I would like to request an edit of prominent theoretical physicists to add in Michio Kaku as he wrote the first string field theory and has published numerous papers on string theory from 1969 to 2000. And has written a best selling physics book physics of the impossible. 95.44.160.38 (talk) 10:37, 10 June 2010 (UTC)

He is certainly a well-known popularizer of theoretical physics, but I have doubt he ranks as a prominent physicist. As I recall, he had some 20 or so refereed journal articles with only two being reasonably well cited. Materialscientist (talk) 10:45, 10 June 2010 (UTC)

I would like to request an edit to prominent theoretical physics in which stephen hawking should be removed as he has not done as much work in the field as the other people in the list and is wildly over publised —Preceding unsigned comment added by 95.44.160.38 (talk) 22:12, 27 June 2010 (UTC)

## Edit Request: Grand Unification Theory and Scalar Field Theory

Grand Unification Theory is listed under proposed theories and fringe theories. It should only be under proposed theories. Scalar field theory should NOT be included under fringe theories, since it is theoretical backbone of spontaneous symmetry breaking which is important in high energy physics and condensed matter physics. I suggest moving Scalar field theory to the mainstream theories section, or removing it all together since it is covered by quantum field theory in the mainstream theories section. I am a doctoral candidate in high energy theory, so I feel justified in commenting on these issues.

Frankly, the Fringe theories section weakens the article and should be removed. There is no reason to point people to pseudoscience when they come looking for theoretical physics. —Preceding unsigned comment added by 70.64.12.112 (talk) 18:47, 21 November 2010 (UTC)

Thanks, changed. Materialscientist (talk) 00:34, 22 November 2010 (UTC)

## Mathematical Vs Theoretical Physics

This article, especially in the lead, makes the wrong distinction between mathematical and theoretical physics and in the process also contradicts the article on mathematical physics. i.e. that of mathematical physics emphasizing rigour in the maths of physics, and theoretical physics emphasizing the 'science' (which is, mathematically, non-rigorous) of physics. Rlinfinity (talk) 00:00, 23 December 2010 (UTC)

The distinction "theoretical physics" versus "experimental physics" is already questionable, if not outright wrong. However, painting mathematical physics as a separate branch of "theoretical physics" is even more questionable. This needs to be fixed.Biophys (talk) 18:51, 17 January 2011 (UTC)
I second (third?) this opinion. Math phys is quite different, but has some overlap with theo phys. Please see the articles on mathematical\theoretical chemistry, mathematical\theoretical biology and mathematical economics\economic theory for examples of this distinction.
Another way of saying this (from the branches of knowledge approach) is that mathematical "x"s tend to interest mathematicians and to be branches of applied mathematics; theoretical "x"s tends to be part of field "x" (all IMHO, of course. Much of this may be subject to academic debate). Thus I regard theoretical physics as focusing more on physical insight and interpretation, rather than mathematical rigour (which may nonetheless be present in spades-loads). In that sense I side with the mathematical physics article. 5.151.82.74 (talk) 02:09, 22 July 2013 (UTC) PS I missed the point about theoretical physics dealing with physical theories, as was mentioned before in the #proposed modification section.5.151.82.74 (talk) 02:35, 22 July 2013 (UTC)

## Gordon Freeman: An inspiration

Alot of the new age of teenagers have gaming consoles, so the programmers at MIT might not have heard of Theoretical Physics, but Gordon Freeman has shown us the power of Physics.

And unlike Star Wars, and the Holocaust, Half-Life can really happen. —Preceding unsigned comment added by 74.83.30.105 (talk) 20:07, 6 April 2011 (UTC)