Enormousdude

Matter (say, a meter stick, an atom, or Solar system) does not expand with expansion of space during Big Bang - simply because size of matter is determined by fundamental constants (say, the size of H and other atoms - by speed of light c and Plank's constant h, the size of planetary orbit - by the gravitational constant G). As long as these (fundamental) constants stay about the same during space expansion, the size of atom, molecule, planet, etc can not change.

At present there are no indications that the value of fundamental constants c,h,G change during Big Bang, at least during last 1000-fold increase of size of Universe.

If matter (say, a meter stick) would expand with the expansion of space then we would not notice expansion of space at all.

RE:"Energy" article

Could you let me know what exactly was incorrect in my corrections (say, about energy or kinetic energy)?

Right now article Energy again has wrong definition of energy (as "ability to do work"). What units does the "ability" have?

Sincerely, Enormousdude.

• The ability to do work has, of course, the same units as work itself.
• I appreciate (and share) your desire to make all definitions rigorous, but there are places where a more intuitive approach is necessary. Some things can't be satisfactorily defined rigorously, and an intuitive explanation is required to provide a shared understanding.
• The current definition of energy is also the one I'm familiar with. It is not essentially different than the one you give here; A more precise formulation fits best later in the article, and not in the introduction. Remember, this is an encyclopedia, not a textbook. This isn't a dictionary either - It's primary purpose is to provide knowledge and understanding, not definitions.
• As also suggested by Linas, you should make sure that your grammar is correct when making edits. Especially note the usage of "the" and "a" (I know these don't exist in Russian, making it perhaps a bit confusing. But please make an effort).

Regards, -- Meni Rosenfeld (talk) 17:06, 15 March 2006 (UTC)

"Ability" is not a quantity - it has no units. If you want to assign units to it, then what units does the "ability" have? Say, "ability" to rotate? If you want to assign units to "ability to do work" quantity (which by the way, also does not exist in physics), then as you said they must be the the units of work (Joule = Newton x meter). Then what is the point to have TWO identical quantities: "work" and "ability to do work" - especially in light of having one ("work") already well defined long ago, and the other ("ability to do work" is not defined at all)?

Sincerely, Enormousdude.

Absolute energy

A recent revision of yours reads: "There is no absolute measure of energy because energy is defined as awork one system does (or can do) on another. Thus, only of the transition of a system from one state into another can be defined and thus measured." Can you source this? I'm curious, because I often hear discussions about cosmologists trying to ascertain better estimates of the total amount of energy in the universe. Robert K S 19:39, 15 June 2007 (UTC)

These are two different issues. Energy is indeed defined as a work one system can do on another system - see, for instance, "McGraw Encyclopedia of physics", 1991 edition, the very begining of article "Energy", page 384. Or see any good physics textbook - they all define work first, and then energy via work done when a system undergoes changes (say, a rock is elevated, or a bullet is accelerating in a gun barrel, or electric charges rearranged from one configuration (say, at infinity) to another (say, given one)). Thus, energy of any static system by itself (say, book on a table) is undefined - because nothing is doing any work on anything. Only when you have changes in a system (so you may identify at least two different states of your system), or when you have at least two interacting with each other systems (like hot and cold bodies in contact or in possible contact) - only then energy can be defined (simply because it takes work to define energy).

Total energy of universe is hard to define because if the universe is defined as a closed system, then it's energy can not change (due to energy conservation) during its evolution. No change (in energy) = no work done. So, we can assign any arbitrary number to an energy of universe - say, 1 Joule. There is nothing this will affect or change. On the other hand, if universe is defined as an open system, then we don't know what and how it interacts with - thus how much work it is doing on its environment - thus how much its energy have changed (say, since the beginingm of big bang, or since January of last year).

On the other hand if we try to add up all known energies in our universe then by a strange twist of nature we end up with zero (indeed, major positive constituent is rest mass of all kind of matter-energy E1=mc^2 and it is exactly counterbalanced by major negative constituent to be energy of gravity of that matter-energy: E2=-Gm^2/R=-E1). In doing so we extrapolate energy density of, say, one cubic light year to all visible universe (which is limited by speed of expansion being equal to speed of light). There is, howeves, some problem with this. Energy being work is frame-dependant. (Say, kinetic energy of a bullet is zero in the refernce frame moving with the same velocity as the bullet). So, extrapolating energy in nearby cubic light year to distant cubic light year (especially to one beyond visible Hubble horizon - thus one moving at speed larger than speed of light) is not clear-cut procedure. Indeed, how can we measure any work in the parts of universe which are beyound our Hubble horizon?

So, I would say that definabe (or countable) energy of universe is zero, undefinable - any number.

Sincerely, Enormousdude 20:36, 15 June 2007 (UTC)

Welcome!

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---

Please be careful about your english grammer. Some of the changes that you made, while technically correct, had bad english grammer, and I think that this might upset some people. Anyway, I invite you to join the conversations on the talk pages of Wikipedia:WikiProject Physics. linas 02:45, 14 March 2006 (UTC)

Thank you, I will pay more attention to my English grammar (does not it spell as grammAr and not as you incorrectly spell it (grammEr), by the way? And should not you capitalize E in English instead of incorrectly writing as english ?) Enormousdude 18:55, 15 March 2006 (UTC)

it should be "doesn't it..." or "does it not..." (not "does not it...") haha :P - BriEnBest (talk) 03:53, 22 January 2008 (UTC)

actually, it should be "isn't it spelled ( = is it not spelled, but not "is not it...") but oh well, I don't care so much - it's cool - it is evidence that you are from Russia, which is cool ;p - BriEnBest (talk) 03:53, 22 January 2008 (UTC)

Non-NPOV contributions to Special Relativity

I have removed your contribution to the SR article regarding the 2nd postulate for the reason that is non-NPOV. Please review the Wikipedia guidelines for contributions. Alfred Centauri 00:33, 19 March 2006 (UTC)

A related note from another editor c is not the coupling constant of electromagnetism anyway. Instead that is something called "epsilon-naught" (a Greek epsilon with a suffix of 0). --EMS | Talk 02:32, 19 March 2006 (UTC)

Who said c (actually c^2) is not the coupling constant of e/m interactions? Only non-educated in physics person can tell that.

Neither permittivity of free space (epsilon naught) nor permeability of free space (mu naught) are the coupling constants of e/m interactions - ask any physics major if in doubt. The permeability of free space is defined as 4 pi 10^-7 (exact), and the permittivity of free space is defined via the speed of light in vacuum - as 1/(mu naugh c^2) - also EXACT.

Should I cite here numerous textbooks - like "University physics" by Young & Freedmann, "Physics for scientists and engineers" by Serway & Jewett, "Modern physics" by John R. Taylor, as well as CODATA recommended list of physical constants (like the list in Physical Review D, volume 66, N 1-I, page 77, July 2002)?

So the Coulomb constant 1/(4 pi epsilon) is therefore equal (10^-7)c^2, and the Coulomb force between charges is proportional to the c^2.

So, please undelete my comments back.

Enormousdude 20:32, 20 March 2006 (UTC)

I just saw this conversation on your talk page. Actually, the coupling constant of electromagnetism is widely known to be the dimensionless fine-structure constant α. –Joke 14:41, 24 March 2006 (UTC)

I am not talking about coupling constant (which actually is the ratio of strength of e/m interactions to nuclear) but about Coulomb constant with is proportional to speed of light squared. This is the constant which reflects not relative but absoute strength of e/m force.

[I have indented the comments of Enormousdude so that they are in accord with Wikipedia talk guidelines.] The reason I removed your contribution regarding the 2nd postulate is because it is non-NPOV. There are many references which explicitly state that the 2nd postulate is not redundant. Thus, your claim that it is redundant is controversial and so cannot be stated as a fact in a Wikipedia article.

For the record, it is my opinion that the 2nd postulate is equivalent to the assertion 'Maxwell's equations, which predict the speed of light is c, correctly describe electromagnetism'. This assertion is not contained within the 1st postulate and so, IMHO, the 2nd postulate is not redundant. Therefore, I will not undelete your contribution as it is non-NPOV. Alfred Centauri 23:09, 20 March 2006 (UTC)

Maxwell equations can not PREDICT speed of light because they are not fundamental - they are just a mathematical CONSEQUENCE of gauge invariance (=existence and conservation of electric charge) within Minkowsky space-time (=symmetry between space and time with given conversion factor between time and space coordinates being fundamental constant c). So, constancy of speed of light is a mathematical consequence of higher than simple Euclidean symmetry our space-time posesses (Minkowskianity of it if you wish), but not vice versa as you trying to insist.- Enormousdude.

I think that you have misread Alfred's statement. The first postulate cannot and does not in any way, shape or form establish that spacetime "possesses Minkowskianity" (or "is Lorentzian" as amny other physicists would say instead). It is the second postulate which does that. As stated, the Loretzian nature of spacetime is inferred from the constancy of c as given in the second postulate when combined with the first postulate. Historically, the constancy of c was inferred from Maxwell's equations. However, I will concede that as a practical matter the foundation principle for relatvistic physics is the Lorentzian nature of spacetime, and agree that Maxwell's equations and the constancy of c arise from that. --EMS | Talk 02:58, 16 June 2007 (UTC)

Theory article

Thank you for that edit. I didn't quite have the courage to just wipe the nonsense right out...Kenosis 15:36, 8 April 2006 (UTC)

Yes, somehow Wikipedia is choke full of garbage. I don't understand why editors don't care. Enormousdude 20:14, 11 April 2006 (UTC)

Edit summaries

Hello. Please remember to always provide an edit summary. Thanks and happy editing. NickelShoe (Talk) 19:12, 11 April 2006 (UTC)

Interesting

Hey. I like our recent additions to physics and philosophy of physics, but they were not constructive in any way, so I reverted them. Karol 22:16, 14 April 2006 (UTC)

Reverts

Dude, most of your edits are not helpful nor particular lucid. In fact, you seem to be getting routinely reverted. How about fewer, but more carefully considered contributions? Nonsuch 17:22, 18 April 2006 (UTC)

As you can see, most of my edits were NOT reverted - after people read textbooks and real encyclopedia, they find that my edits are correct.

And if some are reverted, they are reverted by someone who does not understand the subject much (or in depth) - like passerby laymen. I give them some time to learn. You may look up to compare my (mostly accurate) edits with reverted (less accurate) statements.

This happens because wikipedia is NOT an encyclopedia (as it says in it mission statement), but a wikipedia - collection of opinions. Opinion does not have to be accurate or factual, right? Any opinion is ok (as you can see from numerous inaccurate statements in Wikipedia). Enormousdude 19:35, 18 April 2006 (UTC)

At least 10 of the articles you edited yesterday (17th April 2006) were immediately reverted or substantially corrected. Nonsuch 20:51, 18 April 2006 (UTC)

Again (as I said) - not all editors are educated in the subject they edit. Enormousdude 21:05, 18 April 2006 (UTC)

Clear definitions

Please be careful with your editing. Your page states:

Likes: clear definitions (...)

Dislikes: lack of thereof. Often people lack clear definition of the subject they discuss...

You recently contributed photon density and quantum statistics, which were not very clear or well constructed. Please take a bit more care, and put a bit more effort, into your articles. linas 02:42, 20 April 2006 (UTC)

Energy definition

While it is good to like clear definitions, logic, analythical thinking, it is not so good to be very narrow minded.

Your edit in the definition of energy, was rather narrow minded, it would have been better if you had gone through the history of the page and tried to find out why some one entered the earlier definition. Charlie 09:20, 25 April 2006 (UTC)

What exactly do you mean? I don't understand. Enormousdude 19:13, 25 April 2006 (UTC)

Let me try to explain, you probably very well know that wikipedia is different from a text book of physics. Its readership is much more general, and goes beyond physics students. The word energy, as has, emerged from the contributions from various authors is not just a physics word. It has much wider usage. So I believe that is much more appropriate to include the definition of the word as it is used in the context of physics, a bit later; as has been done. This is just to remove the obvious bias which physicists harbor about the usage of the word. I hope you understand now. Charlie 08:14, 27 April 2006 (UTC)

Hold on, I am not talking about "spiritual energy" or "atrological energy" or "energy emanating from mind" (I sometimes read about those, but have no idea what these are - simply because there are no definitions of these quantities).

Therefore, I am talking about the definition of energy in PHYSICS (where such definition exists (via work) - and is very clear and simple). Because I do research in physics (and teach it too), I have tons of textbooks, encyclopedias and technical literature about various fields of physiscs. I however, do not have much of popular literature (mainly because it is extremely unreliable on terms, definitions and conclusions).

Now, words without definitions are useless, right? There is no way of using say, term "fag" without first clearly explaining what exactly this particular combination of symbols stands for. Obviousely that without a definition different persons may assume different subjects/objects/phenomena abbreviated by the term "fag". Even worse, they may waste precious time and paper (or hard drive space) over and over arguing about properties or actions or the very existence of fag(s) without even realising that each means DIFFERENT animal than someone else - just due to lack of definition.

Enormousdude 22:40, 1 May 2006 (UTC)

Book Of Mormon Article Edits

Enormousdude,

I feel like you're adding a lot of fluff into the Book of Mormon article by writing {according to the Book of Mormon} and other hedging words. It's clear, I believe from the article that everything stated there is the history as recorded in the Book of Mormon. I don't think it's really necessary to add to the article just to make 150% sure that everyone knows that it's only according to the Book of Mormon. I think it would be better to preface the whole article with some comment to that effect, because adding a note every single time is just taking up space that really doesn't need to be. Bo-Lingua 20:09, 25 April 2006 (UTC)

Well, I agree with that provided that Book of Mormon article abides by NPOV policy. Currently it does not - it reads as if Book of Mormon is mostly correct with minor deviations from actuality. But NPOV is compliance with truth and facts, right? Thus, it should be somehow shown that extraordinary claims of Book of Mormon (about large and very advanced ancient jewish civilizations in Americas) should be correctly balanced by facts. Otherwise casual/uneducated reader (who is not familiar with archeology and other facts about the Book) may find Book of Mormon historically more or less correct (which it is not even close to).

If this article can clearly state that the Book of Mormon is not a word of God nor it is authentic record of ancient people (it actually claims to be both), so a reader will not be mislead - then that would be balanced NPOV.

Can this be done?

Enormousdude 21:06, 25 April 2006 (UTC)

Um, hate to intrude, but that would not be NPOV. That would be taking the POV that Mormonism is incorrect. It would be NPOV to state that scientists and historians disagree with the book of Mormon, but stating that it's not the Word of God is extrememly POV. NickelShoe (Talk) 22:29, 25 April 2006 (UTC)

Enormousdude, can we discuss some of your recent edits over on Archaeology and the Book of Mormon. Please don't do a blanket revert without some discussion - you've reintroduced some bad spelling, grammer, superfluous information and general errors that had been corrected as well as remove additions by other knowledgable editors. My main issue is the misrepresentation of the Jaredite civilization. The final battle b/n Shiz and Coriantumr was around Cumorah/Ramah, but the final Jaredite war spanned years, was not fought entirely around Cumorah, and the two million deaths occurred during the entire, multi-year, multi-location war - not just the final battle (in fact the death count was noted before the final battle). Also, I don't recall the BoM ever saying the Jaredites were the first to inhabit the land, but maybe I missed the reference - care to share where you get this from? Those are my main concerns - I have a few others, but let's start with these more objective ones. --FyzixFighter 15:28, 1 May 2006 (UTC)

I see there is a history... Enormousdude: Your edits add much but say very little regarding BOM archeology. If grammar was the only issue, I would feel better, but you seem to have an ideological ax to grind as well. Please stay neutral, use prose that is fitting an encyclopedia, and avoid adding but not contributing. --Rojerts 15:06, 4 July 2007 (UTC)

Can you elaborate on what exactly you mean? I always try to use credible information. Also, could you, please, be specific? Point on something I wrote incorrectly, or if I used non-credible source, etc. Until then, please, refrain from removing the credible information I add by my edits. Sincerely, Enormousdude 20:10, 5 July 2007 (UTC)

Example: Storm Rider's Revision as of 18:40, 4 July 2007, states: "civilizations described in the Book of Mormon have been compared to...". You changed it to "civilizations described in the Book of Mormon are comporable to other ancient civilizations." First off, "comporable" is a misspelled word. I believe you want "comparable," which changes the meaning of that sentence considerably. What is being established in the edit just prior to yours is that scholars have compared Book of Mormon civilizations to X, Y, and Z. You interject J, K, and L in an effort to show that the Book of Mormon cannot be true, for J, K, and L are not the same as Book of Mormon civilizations, which they must necessarily be the same as for the book to be true. This non-neutral POV, presented with misspelled words and other grammatical issues, betrays not only this section but the very principles behind Wikipedia.--Rojerts 22:53, 5 July 2007 (UTC)

NPOV on Creationism

Hi, I agree with some of your edits on Creationism but they are highly WP:NPOV. Please try to keep edits within guidelines. Thanks, JoshuaZ 21:36, 26 April 2006 (UTC)

What exactly do you mean? That scientific POV is biased? I don't understand, please elaborate. Enormousdude 21:38, 26 April 2006 (UTC)

Well, essentially yes, please see in WP:NPOV the guidelines for dealing with pseudoscience. Second, one of your other edits- [1] is false and anyways very much POV. JoshuaZ 04:07, 27 April 2006 (UTC)

Hold on, am I understanding your statement (about NPOV) correctly - that scientific POV is considered BIASED POV? Can you elaborate here in depth - I do not understand this? I think, I may have some language /cultural barrier here, can you explain in details exactly how scientific POV is biased?

Sincerely, Enormousdude 21:45, 1 May 2006 (UTC)

It is a point of view in so far as there are people who disagree with it. That does not mean we need to give them undue weight. To quote from the NPOV page "The task before us is not to describe disputes as though, for example, pseudoscience were on a par with science; rather, the task is to represent the majority (scientific) view as the majority view and the minority (sometimes pseudoscientific) view as the minority view; and, moreover, to explain how scientists have received pseudoscientific theories. This is all in the purview of the task of describing a dispute fairly." JoshuaZ 21:53, 1 May 2006 (UTC)

Hold on, scientific view is actually a view of a tiny MINORITY (scientists represent far less than 1% of Earth population). And it always was the view of just very small minority group.

Enormousdude 22:51, 1 May 2006 (UTC)

Truth article

Hi. I had to revert that last one. This introduction was cautiously consensused by a number of long-participating editors. The current version states it accurately, that although definitions typically provide some reference to fact, it is not agreed what that reference is. The article then proceeds to give the major theories and what they have to say about the issues...Kenosis 23:10, 26 April 2006 (UTC) Incidentally, I appreciated your recent edits to the Theory aritcle...Kenosis 23:11, 26 April 2006 (UTC)

How are you going then to answer the questions in the introduction (stated to be important questions) without definition of the truth?

Enormousdude 23:29, 26 April 2006 (UTC)

As I see it, the problem is that your edit made Wikipedia take a side in the debate, saying what the answers are instead of presenting the debate as it is. NickelShoe (Talk) 04:35, 27 April 2006 (UTC)

No, you did not understand my question yet (or I misexpressed it). My question is as follows: How exactly are you going to answer questions abouth truth without knowing what you are talking about (truth)? About what exactly are you going to talk (asking questions, for example)? By other words, when you ask a question about something undefined (say, about truth) - then about WHAT are you asking the question?

Enormousdude 21:39, 1 May 2006 (UTC)

Joseph Smith, Jr.

I noted your two recent additions to this article and have reverted back to the previous version. The topics you are apparently interested in, such as plural marriage/polygamy and Smith's death, have been broken out into more distinct article to reduce the size of the central article on Smith. Also, some of the perspectives/POV you have added have been discussed and sometimes refined on the talk pages of this and associated articles. I would encourage you to read the archives and talk pages on those topics and perhaps look over the LDS project page - Wikipedia:WikiProject Latter Day Saint movement. These might tell you the best location for opinions and edits. Best wishes. WBardwin 01:04, 27 April 2006 (UTC)

This is not POV, these are just facts. Deleting facts lowers Wikipedia standards which are in dire need of improvements. Please don't delete facts any more.

Enormousdude 01:34, 27 April 2006 (UTC)

On a related note, please use more care in your revisions to Word of Wisdom. Linking to an anti-Mormon reference which is not taken seriously as a scholarly source does not meet the guidelines set at WP:RS, and many of your changes, such as mispelling "pentecostal" and incorrect interpretation that the Word of Wisdom bans grains (it encourages their use) are careless errors which would be easily corrected if you consulted a dictionary or read over the Word of Wisdom's original text carefully. You've stated on your user page that you "[dislike] ignorance. Some make bold statements about what they personally don't know - to only prove themselves wrong when they just open a textbook or learn facts." That's a good goal, it would help the article greatly if you would adhere to it as well. Tijuana Brass^¡Épa!-E@ 03:29, 27 April 2006 (UTC)

Please, take a minute to read the cited source - it is Joseph Smith OWN diary.

Enormousdude 03:34, 27 April 2006 (UTC)

Also, WofW actually encourages to drink wine (of own make). Why don't you read it?

Enormousdude 03:38, 27 April 2006 (UTC)

Sigh... you know, there's a reason that you've been reverted so much lately. Please stop to think over what other people are telling you. Tijuana Brass^¡Épa!-E@ 03:50, 27 April 2006 (UTC)

I took a quick look at the edit wars going on at Word of Wisdom. I can sympathise that you think people are being too quick to revert your edits, and that it is easy to take this personally because you probably spent a lot of time on the writing. However, you have to consider all of the time that went into the article before you came along. These are controvercial topics and the major edits you are doing should probably be discussed on the talk page and agreed upon before implementing. Your sources are also controvercial, so it would be good to discuss them also. This way is slower and can be sometimes frustrating, but it will save you the pain of getting into edit wars. So, pick out a few of the points that are most important to you, drop a message/presentation on the talk page and then solicit comments. If your changes are quality, others will probably agree. uriah923^(talk) 05:14, 27 April 2006 (UTC)

LoL, i think he's been reverted so much, in part, at least because most people in wikipedia are not so smart, and much more arrogant... no i'm just kidding, hehe, i'm sorry >< i'm just joking... :p but no, on the real, most people's lack of intelligence is "directly proportional" to their arrogance :p i'm just kidding. BriEnBest (talk) 07:24, 1 February 2008 (UTC)

Liahona

I've been reading this Russian's talk page and he says that in his religion, a moral compass is like a device called the Liahona. I saw that you edited this article, so I thought I would ask. Is the Russian right? Here's a link to his talk page: http://en.wikipedia.org/wiki/User_talk:Kaspersky_Trust

It's at the very bottom.

Yes, "moral compass" and more accurately "moral orientals" (common russian expression) are a set of personal rules of behavior one does not want to break. He was speaking of those. His american friends, however, refer to different subject (actually to object) - Liahona. Liahona according to Book of Mormon is a brass ball-like device with spindels. God gave this device to Nephi (in ~6 century BC) to show the direction to promised land (America). The device accompanied Nephite family all their jorney from Jerusalem to American continent and indeed not only showed right direction along their jorney but also from time to time displayed God's messages.

Enormousdude 18:20, 1 May 2006 (UTC)

Mathematically entangled

I have listed your newly created page, Mathematically entangled, as an Article for Deletion on the grounds that I think you made that definition up. Could you please add a citation, or visit the discussion page and justify your definition. Nonsuch 18:57, 1 May 2006 (UTC)

If you can find a citation for mathematical quantities mutually related via definition in such a way that they are inverse transforms of each other (like energy and time, position and momentum, frequency and time, angular momentum and angular position, etc) - I would appreciate reference in Wikipedia to that particular phenomenon. Feel free to redirect my references to that article then. This would help to clarify many other definitions - of uncertainty principle, of virtual particles, of spontaneous emission, and explanation of origin of fundamental forces, of Casimir effect, pair creation, etc

Enormousdude 19:38, 1 May 2006 (UTC)

Nuclear warfare

Привет! I reverted your recent addition to nuclear warfare. Я думаю, что я должен напишу вам почему.

First, it makes some suspicious claims and gives no source. For example, you wrote that the British "did not know" that the Soviets could hit European targets with their missiles. I find this unlikely, and it does not contradict the sentence that it follows anyway (which simply says that British bombers could reach the USSR before US bombers would, which seems obvious). You also say that the Soviets had the capacity for 50MT missile warheads. This is false. They built one 50MT bomb as a show device but it was far too big for a missile -- it was almost too big for a bomber. And in any case the sentence again does not contradict the one before it: just because Russia could inflict huge numbers of deaths upon Europe does not negate anything which had been written previously, and in fact is perfectly in line with the British reasoning regarding an independent deterrent (Europe would certain be the first to go in any nuclear confrontation with the USSR, and so did not want to rely on the Americans an ocean away to be their umbrella).

Anyway, I just thought you should know why I reverted it, I hope it is sensible to you. And thank you for putting up with my primitive Russia above. ;-) --Fastfission 19:06, 3 May 2006 (UTC)

This is icorrect. The soviets built big ICBMs namely to accomodate powerful bombs - look up the capacity of first ICBMs - 5 tons (!). Also, you are incorrect about 50 MT bomb. It was deliberately filled half with dummy explosive - to reduce yeild from planned 100 MT. Yet, it produced 57 MT yeild.

The bomb in question- the Tsar Bomba was much too large to be carried by an ICBM. JoshuaZ 23:04, 6 May 2006 (UTC)

Please cite sources

Hello, and welcome to Wikipedia! We welcome and appreciate your contributions, such as Exchange interaction, but we regretfully cannot accept original research. Please find and add a reliable citation to your recent edit so we can verify your work. Uncited information may be removed at any time. Thanks for your efforts, and happy editing! Can't sleep, clown will eat me 12:36, 25 May 2006 (UTC)

Archiving talk page.

You may want to read WP:ARCHIVE. JoshuaZ 18:09, 3 August 2006 (UTC)

Virtual photons

Dude, in some places you wrote that virtual photons are "lowest quantum mechanical energy state of photons". This is nonsense. The energy of a virtual photon can be anything from 0 to infinity. And they are not physical states at all.

In general, I like your contributions. However, please try not to remove whole blocks of text (unless you're sure that they are absolutely wrong): usually there are several different ways to present the subject, and we should keep them all, even if you really like your own approach.

Feel free to let me know if you need support in "physics vs. nonsense" controversies. Yevgeny Kats 20:50, 4 August 2006 (UTC)

Well, when you quantize the energy of e/m field in vacuum (representing arbitrary e/m field by its plane wave Fourier components) you get the eigenvalues of Hamiltonian of those waves to be the sum of terms E_n=(1/2 + n)hf (over all values of wave vectors and polarization), right? Then you label the difference in neighboring energy states (n, n+1) to be the "energy of a radiation quanta" (="a photon" ), to treat e/m field in a simplified "ideal gas of many photons" model. But you immediately find that the ground state of e/m field (n=0, gas with zero photons) still has nonzero value of energy, E_o=hf/2 ("zero-point energy"). To avoid infinities we usually sweep this energy under the rug by introducing photon creation and annnihilation operators. But because only difference in energy is measurable quantity, this creation/annihilation of a photon is physically equivalent to transitions from and to the ground state of e/m field. So, if by a "states of a photon" we mean ALL energy states of e/m field (not only the exited states), then the lowest state represents what we label as a "virtual" state. By "virtual" - we mean that it is physically (but not mathematically) different from other states - simply because there are no more energy levels below it to detect it as the the transition to lower state.

So, while indeed the energy of the ground state of e/m field can be anything (depending on the frequency f of its component plane wave), it still is lowest energy state - thus is undetectable - and thus is labeled (may be subjectively) as a "virtual" state.

May be this is to some degree semantics discussion - what object to call "a photon"? I usually favor mathematical consistency first, and then only interpretation of it in terms of "observable" phenomena. What is your point of view?

What is "physics vs. nonsense controversies" ? I don't know much about it yet.

Sincerely, Enormousdude 21:49, 7 August 2006 (UTC)

Hi! The term "virtual photon" usually refers to a photon appearing as a virtual particle that is described by an internal line in a Feynman diagram. The energy of such a particle can be anything from 0 to infinity. Virtual photons mediate the electromagentic interaction. What you call a "virtual state" or "virtual photons" is usually called "the vacuum" or the "ground state". Yevgeny Kats 22:52, 7 August 2006 (UTC)

Your edits on Big Bang

Please do not add content without citing reliable sources, as you did to Big Bang. If you would like to experiment, please use the sandbox. Thank you. Xiner (talk, email) 21:08, 2 February 2007 (UTC)

Which exactly content do you mean - I have made tons of corrections all over wikipedia? Enormousdude 21:20, 2 February 2007 (UTC)

This edit in particular has no reference. It's great to have a physicist contribute to the article, but such changes must come with references, especially when you're stating so many things as fact. Xiner (talk, email) 21:25, 2 February 2007 (UTC)

Are cosmology/astronomy textbooks or physics encyclopedias ok to cite? I usually don't cite them - simply because what are in textbooks and encyclopedias are already a common knowledge. Anyway, this paragraph you deleted actually is based on Wikipedia article baryogenesis cited right here in the same Big Bang article (and on old Sakharov work about origin of matter in Universe published about 40 years ago - which also was cited in the same Big Bang article).

Sincerely, Enormousdude 21:57, 2 February 2007 (UTC)

Please note that Wikipedia is based on Wikipedia:Verifiability, not truthfulness. What cannot be verified by other editors can be deleted. If you work in the scientific field, you should know that citations are mandatory. I just don't want to see your work go to waste, is all. Xiner (talk, email) 22:07, 2 February 2007 (UTC)

Also, I clamped down on unsourced materials from some religious editors just recently, so I have to be fair now. Xiner (talk, email) 22:09, 2 February 2007 (UTC)

So, you don't trust textbooks, encyclopedias and peer-rewiewed publications (which I usually use as sources for my many Wikipedia articles and edits and used for Big Bang article editing)? Also, you don't trust "baryogenesis" article of Wikipedia itself - which I also used information from in the deleted by you section of Big Bang article? I don't understand. Enormousdude 23:30, 8 February 2007 (UTC)

Big Bang

Hi. I've reverted your edits to the article because we've been through this before. It's got no references and written in a decidedly non-WP:NPOV way. Please review WP:OR before you edit the article again. Thanks. Xiner (talk, email) 20:29, 22 February 2007 (UTC)

Changes

Hi there - contentious changes, such as those you are making to Physics, Fact, Truth amongst others are best taken to the relevant discussion pages. I see from this talk page, and from your edits tonight, that you aren't really discussing the changes you are making - that is not really helpful (especially on important lead sections of articles). I would suggest you get involved in discussion the issues with other editors, before changes are made to the lead sections of some pretty fundamental articles. Thanks, SFC9394 00:05, 6 March 2007 (UTC)

I am always ready for explanations (which actually are already there - in various textbooks and serious encyclopedias from which I get most info) - just ask a concrete question.

Sincerely, Enormousdude 00:11, 6 March 2007 (UTC)

Special relativity

You keep placing into special relativity

It is obvious that second postulate is redundant because it follows from the first one (indeed, if laws of electromagnetism are the same in all inertial frames, then the speed of light must be the same in all inertial reference frames too).

That no second postulate is needed is hardly true. Instead, you are explicitly saying that the laws of electromagnetism are the same in all inretial frames of reference, and this is something that is not true in Newtonian physics. So your "second postulate" involves electromanetism as a whole, from which you would derive the constancy of c and from there be able to derive the Lorentz transformations. IMO, it is more efficient to use the constancy of c as the second postulate and demonstrate that EM is Lorentz invarient afterwards. --EMS | Talk 18:29, 1 April 2007 (UTC)

I don't quite follow what do you mean - if laws of e/m are the same in all inertial reference frames, then the speed of light must be the same too (because it follows from wave equation which follows from Maxwell equations). Also, don't forget that c^2 is the Coulomb constant (multiplied by 10^7).

How more obvious can be that including e/m laws in first postulate automaticly makes c the same in all inertial frames - and thus second postulate to be redundant?

Sincerely, Enormousdude 21:06, 4 April 2007 (UTC)

---

The fact the the current standards of time and distance assume the correctness of SR does not make SR "correct by definition", and your edits to that effect are most unwelcome because of that. Those definitions are evidence to the extent to which relativity is now an accepted theory, but the evidence of its outright correctness lies in its consistency with observation, and need not be sought elsewhere. --EMS | Talk 20:05, 4 April 2007 (UTC)

---

It does. The fact that someone does not like my edit does not mean that the edit is incorrect. Usually it is vice versa - it takes for people to learn textbooks to understand that my edits are almost always correct - so it is not my fault that some Wiki editors don't like my comments or edits (just because they are ignorant in the subject they edit).

Back to the subject (SR). Look up introductory chapter in any physics text - it starts with the definition of distance (meter)and time (second). Time interval (second) is defined dimensionless - as so many oscillations of hyperfine transition in Cs-133 atom (to be more accurate - exactly 9 192 631 770 periods). But not so for space interval (meter) - it is defined via the speed of light - the distance traveled by light in vacuum in exactly 1/299 792 458 second (or 30.66331899 periods of oscillations of Cs atom). Thus, speed of light becomes constant (299 792 458 m/s - exact) simply by definition of length - which we use each time we measure distances in space. So, as long as we use meter as defined, SR is absolutely correct simply by definition.

Of course, you may use your own proprietary meter stick (or time interval) to measure things - but that has nothing to do with accepted standards and accepted measurements anymore. And of course, your measurements will then disagree with the rest of the world's measurements.

Sincerely, Enormousdude 21:06, 4 April 2007 (UTC)

The point is more philosophical than practical. The definition is accepting the correctness of special relativity, not defining it. The correctness of SR itself has nothing to do with the definition. The laws of nature are as they are, and no action on our part can change them. SR did not become correct when the meter was redefined, but instead had always been correct. --EMS | Talk 21:38, 4 April 2007 (UTC)

The claim that special relativity is true by definition (and, thus, not a scientific theory) is a very strong claim, which needs to be attributed to reliable sources (like standard text books) in order to be acceptable in Wikipedia. I saw that your claim has been reverted by several editors on special relativity. Please do not add it against the consensus without an explanation on the talk page, preferably mentioning some references. -- Jitse Niesen (talk) 14:54, 15 April 2007 (UTC)

It is not a claim whatsoever. You misunderstood. It is just a definition (of a meter) which fixes speed of light. That is how we (scientists) define and measure distance. Read an introductory chapter in any physics textbook. I am very surprised that "editors" of this page do not know basic definitions of basic physics quantities. How can someone edit what he does not know? Sincerely, Enormousdude 16:51, 15 April 2007 (UTC)

This definition of distance is a consequence of special relativity. You are using it to alter the definition of special relativity. The reason why this is a circular argument has been explained to you by multiple editors. Please do not make edits to special relativity against consensus. Instead, present your arguments on the talk page and attempt to establish consensus for your changes before making them. --Christopher Thomas 17:58, 15 April 2007 (UTC)

Not true. You don't understand how physics works. We, physicists, use clear definitions (same as mathematicians do). Definitions are very important, and shall be clearly understood before one try to judge their logical consequences. Let's open introductory chapter into any physics textbook and read definitions of time and space intervals (I hope you can fetch one in library or somewhere around). Meter is defined as the distance light travels in 1/299792458 second. Plain and clear. Speed of light is therefore fixed BY this very DEFINITION (of length being rigidly coupled with the definition of time interval) - NOT by some EXPERIMENT(S). Any attempt to measure speed of light using this conventional definition of length will return exactly 1 m/(1/299792458 sec)= 299792458 m/sec. There is nothing circular here. Sincerely, Enormousdude 18:25, 15 April 2007 (UTC)

What you are saying is "Since the definition of the meter assumes that SR is correct, SR is now correct be definition". That conclusion does not automatically follow from the fact presented, and even if it did your making that connection on your own amounts to a novel synthesis and therefore is original research. As such, it is inadmissible in the special relativity article. --EMS | Talk 17:04, 17 April 2007 (UTC)

ED, from looking briefly at this discussion, I think there may be some confusion between the theoretical aspects and the operational definitions. From the theoretical standpoint, one must establish that space has the structure of the Lorentz metric---Einstein got there by postulating the constancy of the speed of light along with invariance of inertial frames. Operationally, one defines the time interval because it's easy to do so precisely, then because the speed of light is also easy to measure precisely, one defines the meter (hard to measure precisely) in terms of the second and the speed of light. That operational definition of the meter is well-motivated by knowledge of special relativity, but it's logically unrelated---dimensions are the only relevant issue. Hope this helps. Gnixon 18:12, 15 April 2007 (UTC)

SR edits

Hi, Enormousdude. I've replied to your comment on my talk page. Sorry for any misunderstandings. Gnixon 17:14, 15 April 2007 (UTC)

But for the record: Gnixon also "edits" the Evolution article without any real background in the field, either. At least two of us over there are frustrated about this too. He wastes a tremendous amount of everyone's time leading lengthy discussions on nothing at all, or else trying to discuss content in ways that show he barely understands the subjects better than a college undergraduate might. He has also expressed the opinion that "experts shouldn't expect to have their holy authority worshipped at every turn", so please watch out for that, if it comes your way. Kind regards, TxMCJ 01:38, 16 April 2007 (UTC)

Thank you, I did not know that. Gnixon did not tell me what his occupation is - it means that he is not a physicist nor has substantial expertise in physics. How can someone without expertise in specific subject judge/edit/advice on this subject? It is nonsense. Should not then such uneducated "editor" be punished fot his/her ignorant "corrections" - because this is a vandalism to remove or correct expert's opinion (which usually takes hard work and verification with many reputable sources) by ignorant/incorrect layman opinion - and thus to make Wikipedia inaccurate. Or should this kind of behavior be ignored (acceptable)? - And thus should I also go to any article (even well outside of my expertise), remove experts' opinion from it and replace it with some uneducated garbage?! Enormousdude 22:30, 16 April 2007 (UTC)

For the record, TxMCJ (talk • contribs) appears to be a single-purpose account dedicated to editing Evolution (edit | talk | history | links | watch | logs), active since 27 March 2007 only (barring the first 7 edits out of 417). --Christopher Thomas 02:40, 16 April 2007 (UTC)

Thanks, Chris. TxMCJ and I have bumped heads for reasons that are totally unrelated to anything here. Gnixon 03:09, 16 April 2007 (UTC)

Regarding your comment on Gnixon's talk page

To Enormousdude: "Ignorance is not excuse for vandalism." right back at you. Definitions do not make things true or false, at least not in Physics. The metre was defined in terms of the second and the speed of light in a vacuum only long after it was well established that the speed of light in a vacuum is constant (in a local inertial frame of reference). But I guess that you, not being a physicist, would not understand that. JRSpriggs 07:40, 16 April 2007 (UTC)

Incorrect. Definitions more than make things true or false - they actually make things. There are no things without definition. For example, there is no such thing as "a force" id you don't (or can't) define it. But when you write that dp/dt is what we call "a force", then force is born. And obviousely, then F=dp/dt becomes absolutely correct (simply by definition), and F≠dp/dt becomes absolutely incorrect (also by definition).

So, you can not say that speed of light is constant (or not constant) BEFORE you define distance and time (simply because SPEED does not exist before distance and time are defined). Only AFTER space and time intervals are defined it makes sense to state that speed of light (or of anything else) is constant or not. Currently accepted definitions of space and time are rigidly linked via speed of light - making speed of light itself a constant simply by definition.

Where did you incorrectly concluded from that I am not a physicist? Actually I am - did not you read it on my wikipage? I do research in physics and engineering, I teach physics, publish papers, report in physics (and engineering) conferences/meetings, judge in NSF and other panels (distribution of grants), receive various grants for research (from NSF, DOD, DOE, etc) and do all other activities regular physicists do. I have PhD-equivalent degree (which is called "candidat of physical-mathematical sciences" in Russia) in atomic/plasma physics and master-eqivalent degree in electronic engineering. (I even received US green card and US sitizenship as an outstanding scolar in less than 2 weeks). What else should I do to be called a physicist? Tell me. Are you a physicist? How much experience in research do you have? What kind of degrees do you hold? How many publications do you have? How many panels were you a member of? How long and on what level do you teach physics?

Sincerely, Enormousdude 22:09, 16 April 2007 (UTC)

You said "There are no things without definition.". This is a very serious philosophical error. No wonder you are confused. I suggest you read Ayn Rand's Introduction to Objectivist Epistemology. JRSpriggs 02:39, 17 April 2007 (UTC)

You did not answer my question. Are you a physicist? How much research and teaching experience do you have? How many publications do you have? And on what ground did you call me non-physicist? I presume you are not a physicist yourself, otherwise you would know basic definitions.

Regarding your deeply incorrect philosophical remark - please name a few existing things which are not defined. And substantiate your examples by logic, please. By the way, do you know that philosophy is not a science but a humanitarian discipline (thus is highly subjective), and that philosophers' opinions are never used in science to substantiate anything - namely due to lack of clear definitions, and too broad generalizations (without reference to facts or definitions), and again often due to subjectivity. In physics we do not use opinions of philosophers either. Instead we use clear definitions, mathematics (which is a form of logic), and constantly check our conclusions on agreement with observations (facts).

Sincerely, Enormousdude 14:23, 17 April 2007 (UTC)

I can't speak for JRSpriggs, but I will tell you that I was very surprised to see the claim on your user page of having a Ph.D. is physics given your edits. I won't claim that you are ignorant of the physics, but you do seem to be ignorant of the philisophy behind the physics. I have majored in physics myself and in my spare time do research into a modification of general relativity theory. So I too have knowledge here.

You are not the first well-qualified editor to have trouble here. To be able to function here, you have to respect the other editors. If you do, you will earn their trust and respect in turn. Imposing your own view here, even if it is correct, creates nothing but trouble. If you are right, then you should be able to bring the community around to your viewpoint. If you are not, then the community should be able to bring you around to theirs. So far, you have shown no ability to either bring us around or to be brought around. That is the mark of a bad editor, even if that editor is a certified genius. --EMS | Talk 17:28, 17 April 2007 (UTC)

Again: we (professional physicists) do NOT use philosophy in definitions. Philosophy is not a science, it is a humanitarian discipline defined as "love of wisdom". Love/hate is NOT appropriate emotion when object or phenomenon needs to be accurately defined. As to the wisdom (=knowledge) itself - in order to find it, you have to go NOT to philosophy, but to the particular science branch which holds this knowledge: physics, mathematics, chemistry, biology, genetics, geology, astronomy, cosmology, etc. So, philosophical arguments are weak arguments, and practically never used in physics. Usually it is vice versa - physics or mathematics discovers or accurately defines something first (say: time, space, causality, speed, force, energy, symmetries, conservation laws, relativity, uncertainty, waves, wavefunction, holography, Big Bang, inflation, etc) and investigates its properties. And then philosophy borrows these definitions, aberrates them and uses them incorrectly generalizing well beyond established by their definition applicability range (stating, say, that "universe is a hologram" or that "thoughts are superliminous" - without actually understanding definitions of what is a hologram or what is a thought).

It is not my fault that "editors" do not know definition of velocity, definition of distance (space interval) and definition of time interval. They should then open textbooks and learn, not me. It is not my problem that they never accurately read "relativity" chapter in a good physics textbook.

I went into library to take a look at some textbooks. Here is what I found:

Let's take even introductory text - say Young and Geller 8th edition "College Physics" textbook (ISBN 0-8053-9070-7, 2006):

"Thus, a direct consequence of Einstein's principle of relativity, sometimes called the second postulate of relativity, is this statement: "The speed of light is the same in all inertial frames of reference and is independent of the motion of the source".", page 901.

Or let's open some university-level textbooks - say, Knight's "Physics for scientists and engineers" (ISBN 0-8053-8960-1, 2004), also "Relativity" chapter:

"Principle of relativity: All the laws of physics are the same in all inertial reference frames. All of the results of Einstein's theory of relativityflow from this one simple statement" (p 1158). In this particular textbook authors don't even bother mentioning second postulate at all - they just state a few paragraphs below that because Maxwell equations must be true in all inertial reference frames (as principle of relativity requires), then the speed of light must be equal to c = 3x10⁸ m/s in ALL inertial reference frames.

Another (older) textbook ("College physics" by Serway & Faugh, 5th edition, ISBN # 0-0302-3798-0, 1999) opened at p. 861:

"Einstein based his special relativity on the following general hypothesis, which is called the principle of relativity: All the laws of physics are the same in all inertial frames. An immediate consequence of the principle of relativity is that The speed of light in a vacuum has the same value. c = 2.997 924 58 x 10⁸ m/s, in all inertial frames."

Should I worry about those ignorant "editors" who don't even read textbooks (or don't understand definitions of fundamental physical quantities also found in same textbooks)? No, THEIR ignorance is obviousely not my problem - it is THEIR problem. May be some of them just love to embarass themself on wiki pages (by reverting my corrections or making absurd statements, or refering to philosophy as a source of information/opinion while discussing physics or mathematics). That is completely fine with me - I like fun (and even share it with my students). If someone who is not a physicist edits physics articles incorrect, or if someone does not want to learn, why should it be my duty to educate him/her? There are good schools, textbooks and encyclopedias around for that. It is his/her personal ignorance problem (=lack of education) and as a consequence - his embarassment, not mine.

Sincerely, Enormousdude 21:01, 17 April 2007 (UTC)

What you still don't get ED, is what is left unsaid in the quotes you have provided. For example, you quote "Maxwell equations must be true in all inertial reference frames (as principle of relativity requires)...". What is left unsaid here? Try adding this to the front of your quote: If Maxwells equations are physical laws, then. Thus, the 2nd postulate is, in effect, changing that If to As. Why is it so hard for you to see this? The POR is a simply a requirement for the form of physical laws but it certainly doesn't sanction a particular law! Alfred Centauri 00:40, 18 April 2007 (UTC)

Of course, Maxwell equations ARE laws of physics! Only uneducated in physics does not know that. They are even CALLED laws: Gauss's law, Amper's law, Faraday's law. What Maxwell did is simply to describe these experimentally established before him laws in consize mathematical form. Enormousdude 20:42, 15 May 2007 (UTC)

I just looked up a reference that supports my point above. This is a quote from "Einstein's Legacy" by Julian Schwinger:

1. The Principle of Relativity: The description of all phenonmena provided by any two inertial observers in uniform relative motion are equally valid; the laws of physics are the same in both of them.

2. Among those laws is the absoluteness of the speed of light in a vacuum; that speed is the same for any two inertial observers in uniform relative motion.

I've bolded the crucial phrase among those laws. Do you see? Alfred Centauri 01:19, 18 April 2007 (UTC)

Now you contradict to yourself and proved my point. Indeed, if as you said "laws of physics are the same in both of them" , then all constants of physics (including the speed of light) must be the same too. If to separate speed of light from other constants into special postulate, then two postulates are NOT enough - you must add 3rd about constancy of Plank's constant, then 4th - about constancy of gravitational constant G, then 5th about constancy of charge of electron e, and so on - as many more as needed to list ALL known physical constants. Then, according to your logic (of separating constants from laws) special relativity must be based on 8-5 postulates, NOT on the 2 you proposed above. But as you now see - your all but one postulates are logical consequences of the first one. That exactly is my poin (and not only my but of professional physics community who writes and edits current textbooks). That is actually beyond somebody's opinion - because it simply follows from the formulation of the first postulate which is so general that it includes ALL phenomena - ALL laws of physics (not only mechanics as you incorrectly understand - first postulate does not actually say anything about mechanics). Enormousdude 22:28, 15 May 2007 (UTC)

I have added additional refuting references at talk:special relativity. --EMS | Talk 02:24, 18 April 2007 (UTC)

They do not refute but actually strengthen my (and textbook author's) point of view that second postulate is redundant. Obviousely if first postulate says that ALL laws of physics should be the same in any inertial reference frame, the laws of electromagnetism must be the SAME as well - which immediately imply that the speed of light must be the same. Of course, not only c but other fundamental constants (like h,e,G) must mbe the same in any inertial frame (and they are indeed independent as experiment shows). So you are obviousely incorrect about non-redundancy of second postulate (and I am correct about its redundancy). Sorry for that. Sincerely, Enormousdude 19:43, 21 August 2007 (UTC)

Why can't you guys work *with* him instead of against him? He's not going to learn all the complexities of english grammar overnight - it might take a long time, but if you guys are actually friendly, then i think he will learn that much faster - it takes friendly interaction and communication to learn a new language.

Personally, I like his edits much better than anyone else's regarding the physics articles. They are easy to understand and the logic is clear. BriEnBest (talk) 07:38, 1 February 2008 (UTC)

Your attitude

Enormousdude -

You wrote above that:

The fact that someone does not like my edit does not mean that the edit is incorrect. ... [M]y edits are almost always correct - so it is not my fault that some Wiki editors don't like my comments or edits

Oh yes it is your fault! This is a WIKI, and as such it is a collabotative effort. To get a controversial edit into place, you have to make a case for it, and not runroughshod over the other editors! You have failed to make your case, and constantly reverting special relativity to your preferred form is not appropriate! --EMS | Talk 15:43, 17 April 2007 (UTC)

There is no controversy here - those editors who revert my correct edits simply are not physicists or don't read physics textbooks. What can I say - they only embarass themselves by deleting my correct information or replacing it with their incorrect one. See above citations from a few physics textbooks.

Sincerely, Enormousdude 21:10, 17 April 2007 (UTC)

There is a controversy here, based on your edits being reverted. Wikipedia does not care about "truth". Instead Wikipedia cares about verifiability. If you want your edits to stick, the first post your citations for the above thread at talk:special relativity, and engage us in a discussion of their worth and relevance. I will not guarentee any acceptance of your edits, but that is material that we will need to refute with other material if your edits are not to be admitted.

There is no tolerance here for editors who take a stand of "let me do as I please whether you agree with me or not". If you do not care to be part of a collaborative effort, then you should not be here. --EMS | Talk 22:22, 17 April 2007 (UTC)

Removal of second postulate might not be so bad at all. But then there must be some postulate that invariant speed is finite, positive and real, or in other words, using reference Enormousdude gave, there must be postulate that saying K > 0. If there would be K = 0, then we would have Galilean transformations, and for K < 0, only possible speeds (for sake of consistency) would be speeds higher or equal to invariant speed, so all particles would behave like tachyons which is obviously not the case. --83.131.87.100 12:28, 18 June 2007 (UTC)

Let's see: You are saying that "removal of the second postulate might not be so bad after all", but are then calling for $K=1/c^{2}$ (with respect to the above references article) to be a postulate instead. IMO, $K=1/c^{2}$ is equivalent to the seond postulate. --EMS | Talk 14:45, 18 June 2007 (UTC)

Not exactly. Second postulate says that speed of light in a vacuum is a universal constant, which is independent of the motion of the light source. It would be more simple and more general to simply say that invariant speed is finite. Constancy of invariant speed follows from the first postulate, and fact that speed of light is invariant speed is not necessary to derive Special Relativity, and it can be later shown that speed of propagation of EM radiation in vacuum is equal to invariant speed. Introducing something called speed of light instead of something called invariant speed in postulates can generate common misconception that Special Relativity is consequence of laws of electromagnetism. --83.131.19.15 22:01, 22 June 2007 (UTC)

In defense of him, I think a few things: 1) the subject called "your attitude" and then criticizing his actions is borderline / past border-line personal attack (that is just my opinion though). 2) I tend to believe someone who has multiple degrees in physics over someone who doesn't have a degree in physics, *IN THE SAME WAY I BELIEVE SOURCES LIKE school textbooks over BILL'S WEBSITE,* so it relates to your argument about him citing sources. 3) although I agree with the points you are making (he should cite sources, etc.) I would like to point out to you (with all due respect) that your tone is dis-respecting, and threatening, and I for one do not appreciate seeing that (i'm sure in the same way you do not appreciate seeing him "break other rules" as some might say).

A solution: all you have to do is make the same statements with a more respectful tone. Feel the love. - BriEnBest (talk) 03:29, 22 January 2008 (UTC)

Relativity

Hi, ED. Thanks for providing those references. I'm sorry these conversations have gotten so combative---probably both sides could be more cooperative. You clearly know a lot about physics, and there's no reason to doubt you're an experienced researcher, so I think these disagreements must somehow be caused by miscommunication. Since there are some subtle issues being discussed, maybe all of this is just a big misunderstanding.

Thanks again for the references---they help immensely. I don't have any of those texts on hand, but I can look them up tomorrow, and I do have a few others. After reviewing Resnick/Halliday/Krane, French, Goldstein, and Marion Thornton, one in particular (Marion-Thornton) seems to describe the relevant issues clearly.

First of all, in the section on Newtonian mechanics, it mentions "Galilean invariance" and the "principle of Newtonian relativity." Then, in the chapter on special relativity, we find

The basis of relativity theory is contained in two postulates.

but shortly thereafter,

Postulate I, which Einstein called the "principle of relativity," is the fundamental basis for the theory of relativity. Postulate II, the law of propagation of light, follows from Postulate I if we accept, as Einstein did, that Maxwell's equations are fundamental laws of physics.

So I think these disagreements have been based on an issue of perspective. If one knows nothing except the principle of relativity, then the second postulate is necessary---indeed, since Newtonian mechanics satisfies the principle of relativity, that principle alone can't lead to SR. That's why Einstein included the 2nd postulate. However, if we accept E&M, or the fact that massive particles don't accelarate linearly forever with a constant force (mentioned by French), or indeed any of the abounding evidence that there's a "speed limit" in the universe, then the full structure of SR can be derived from only the principle of relativity.

I would also mention that French assumes the principle of relativity has always been accepted (considering the Newtonian version), and so considers the second postulate to be Einstein's true innovation. Clearly things depend on one's point of view.

My personal point of view is that the true innovation came from realizing there could be some sort of inter-relation between space and time---that was a revolutionary idea, and it's what allowed Einstein to reconcile the truths of his two postulates.

Do you think that's a reasonable understanding of things? If so, maybe we can all work together to find a way to explain things in the article. I'd be happy to discuss things further. Regards, Gnixon 01:13, 18 April 2007 (UTC)

Jokes

By the way, I'm sending your jokes to some of my friends. I especially like the second one, which should be good for ribbing some of the philosophers I know. Cheers, Gnixon 01:48, 18 April 2007 (UTC)

Freedom of enterprise

You wrote on your user page:

Surprised: about very low quality of education in the US (compared to Russia and Europe in general). Hey, does not this country deserve a little better? Is it just me, or it is all about sacred "freedom of enterprise"? (=the more of ignorants walk around, the more money smarts can make on them - therefore the more benefits will return to the society via high bracket taxes and charitation of one)? Or am I missing something else here?

I agree that the education in the USA is, in some areas and in some ways, very low quality. Whether this (the USA) deserves better is not a good question. The question should be why is this so and the answer is, IMHO, precisely that education here in the USA is, in general, not free enterprise. And yes, free enterprise is, IMHO, sacred. It is the only moral system. Alfred Centauri 01:42, 28 April 2007 (UTC)

Magnetic field

You made some excellent edits on magnetic field. However, somebody reverted some of your edits, so you might want to take a look on what was done. --83.131.87.100 12:02, 18 June 2007 (UTC)

Energy definition from work

I notice you keep readding the work definition--but it's an edit that doesn't have consensus. Please do not readd it to the intro. If you want to discuss it further, go ahead and bring it up on the talk page, continuing from the discussion here. Robert K S 18:02, 23 June 2007 (UTC)

It is accepted by us, physicists, definition of energy. See the referenced source I cite - "McGraw Encyclopedia of Physics", 1993, the very beginning of the article "Energy". Or see any good physics textbook - they all define work first, and then define various forms of energy via work. This is most common scientific definition, and the one from which both units of energy and most (if not all) known forms of energy (kinetic, potential, thermal, chemical, etc.) are defined.

You may notice that most editors of this article are not physicists, so they are not competent in this subject. I tried to discuss physical definitions with some of them but turns out that they were too ignorant in physics and were denying even basic textbook definitions (say, definitions of space, time, mass, momentum, force, energy, magnetic field, temperature, entropy, etc.)

I think, it is just lack of education and experience in physics among most editors who edit articles in Wikipedia. I don't understand why some of them write nonsense without even opening a textbook or encyclopedia.

It takes not only good education but also long years working actively in the field of physics to become professional and to clearly understand definitions and properties of physical quantities. Without such understanding editors are just lost in nonsense (or in lack of logic), and their poor "edits" become major embarrassment for Wikipedia.

If you are a physicist, then just tell me what do you have against common textbook definition of energy.

Sincerely, Enormousdude 20:33, 23 June 2007 (UTC)

Oh, shush. You're not even reading the discussion that's taking place. Robert K S 20:45, 23 June 2007 (UTC)

I do. Usually I do not interfere because most statements there are plain incorrect due to the fact that they are made by non-specialists. It is just plain waste of time to discuss with someone what he/she does not understand. For example, I try to explain to someone that there is no such thing as magnetic poles - but he does not understand, making the same stupid claim that magnetic force is directed along magnetic field lines. Another current example - now someone who is not a PHYSICIST but a PHYSICIAN edits "Energy" article - embarrassingly deleting common definition of energy just because he does not understand the difference between heat and thermal energy. Should I edit medical articles too?

Enormousdude 21:28, 23 June 2007 (UTC)

The concern you're elborating is not germane to the discussion that I linked to above and the new one at the bottom the Energy talk page. Robert K S 22:09, 23 June 2007 (UTC)

I 100% agree with enormousdude - you guys ruined the article. I finally found the *definition* of energy HERE, on his talk page - since it was oddly missing from the article, thanks to you and harris, as quoted by sbharris "me and roberts and others decided to delete the definition of energy since heat 'is not' thermal energy" etc....... BriEnBest (talk) 07:07, 1 February 2008 (UTC)

Invite

Gregbard 07:12, 14 July 2007 (UTC)

Force

I have noted your edits in Force. They were reverted. I just want to tell you that I try to write something similar to the article may be already two years and it always dissappears soon or later. Please, see Talk:Force#Correct definition of force. It seems, it would be necessary to cite the statements precisely. I have very limited access to literature (I do have Feynman's lectures but not in English). Could you help? Thanks. Miraceti 09:06, 25 July 2007 (UTC)

And again you make the same comments. Is this a belief you have derived yourself, or is it the way mechanics is taught in your home country? I am genuinely curious. English-language textbooks (including the Feynmann lectures) which discuss the notion of force firmly oppose the use of Newton's second law as a definition (other textbooks are cited in the article). This is consistent with the way the subject is taught in the UK, including by me. Newton himself clearly is presenting his laws as empirical facts, not definitions (not that Newton's presentation should always be taken at face value). See also the discussion by Walter Noll of Carnagie-Mellon, linked at the bottom of Talk:Force. PaddyLeahy 18:44, 21 August 2007 (UTC)

Yes, this is the way I was taught: F=dp/dt is the definition of a force. Of course, your textbooks (and you pesonally) can teach whatever you want and define force as whatever you wish (how do you define it to students, by the way?), but dp/dt is THE ONLY accurate mathematical (=logically consistent) definition of force available in classical mechanics. Sorry about reminding that. Sincerely, Enormousdude 19:34, 21 August 2007 (UTC)

So which of these statements do you disagree with?

• What makes physics more than just a branch of mathematics is that some of the terms in the equations of physics are not defined by the equations, but instead are defined empirically, via operational procedures in the laboratory.
• Canonical examples of such terms in classical physics include position and time. From these, velocity and acceleration are defined mathematically.
• The difference between a physical law and a definition is that in the former case, all the terms in the equation can be defined directly or indirectly via laboratory procedures, and those procedures are not based, directly or indirectly, on the law in question.
• Forces are routinely measured using conditions of static equilibrium (balances). (And have been since ancient times, at least in the case of weights).
• Boyle's law and Hooke's law were discovered through quantitative measurements (using static equilibrium with weights) years before the equation F=dp/dt was known.

If you accept all the above, I cannot see how you could disagree that the assertion that Net force is proportional to acceleration for a given body is an empirical relation which can be tested in the laboratory without circular reasoning, i.e., a law and not a definition.

Incidentally, if you insist that Newton's law is a definition of force, how do you define inertial mass? Many textbooks claim that the latter can only be defined as the proportionality constant in Newton's law. Surely the same equation cannot be a definition for two of the terms in it? PaddyLeahy 09:23, 22 August 2007 (UTC)

Let's start with mathematics. What is mathematics? Mathematics is simply formalized logic and nothing else. If... then... - that is ALL and ONLY which mathematics is about, nothing more, and nothing less. What is a logic, on the other hand? Logic is just a system of non self-contradicting rules. Obviousely, universe(s) and all objects in it can not contradict itself - that is why universe obeys logic, hense obeys mathematics. Of course, mathematics is more rich than universe (this is not important for now but as we see later becomes vital for distinguishing between the physics of our universe and mathematics in general.) Application of mathematics to the universe we live in (actually to measurable by us corner of it) is called physics. For example: if shifts in time do not matter then the quantity which is the canonical congugate to time must conserve (we call this quantity an energy/work). If space is defined via time and via the speed of light then the special relativity theory becomes absolutely correct (simply by definition of space/time as being related by c). And so on. Now, in mathematics we define every quantity and every object via previousely defined quantities and objects. Exactly same in physics. Going along definition chains this way we quickly run to fundamental quantities and fundamental objects (==the beginning of all definitions). In mathematics (=logic) fundamental objects are binary (=mutually exclusive) operators like true/false, yes/no, +/-, and also related to them fundamental numbers 1/0. In physics fundamental quantities are also in the beginning of a definition chain: time, space, mass. Those CAN NOT be defined via anything else simply because everything else (like momentum, energy, temperature, electric charge, etc) is already defined via them. That is what we teach students in the very beginning of studying physics - definitions of basic physical quantities (usually in 1st chapter of any physics textbook). These definitions MUST BE empirical - by definition physics is an APPLIED mathematics - because we want it (physics) to relate OBSERVABLE quantities, not just abstract mathematical objects. So, we correspond certain observables (time, space and mass) to mathematical objects (t,r,m) in certain particular way which is defined by units and measurement procedure: the tandard time interval - a second - is defined as being exactly 9,192,631,770 oscillations of hyperfine transition in 133Cs atom; the standard space interval is the distance light travels in exactly 1/299,792,458 second, the standard mass interval is exactly the certain piece of PtIr alloy held in Sevres). Then we define compound quantities (velocity, momentum, acceleration, force, work/energy, temperature, etc) via these fundamental quantities or via previousely defined via them compound quantities. Most laws of physics then follow from these definitions of compound quantities (like F=dp/dt=ma) automatically. But some don't. Say, energy conservation mathematically requires that dt intervals must be the same at all times t; momentum conservation requires that dr must be the same everywhere (for any r), and so on. Then we say the following: we know from experiments that energy/work conserves, hence dt must be the same for any t. Here is the difference between mathematics and physics (which is simply mathematics applied to our particular universe). Because we don't know if dt is the same for any t in our particular universe (for mathematics it does not matter whatsoever) then when we discover that energy conserves (in the spherical corner of Universe as far as we can see - for about 13 billion light years or so), we have to acknowledge that dt intervals are the same (for our particular corner of universe). By other words, in our visible universe nothing depends on time per se (as well as on location, on direction and on speed of uniform motion). We now call these statements as "laws of physics" which are actually simple statement that nothing depends on some certain quantities (time, space, velocity) defined by us in a certain way. In lower level classes we keep calling these laws as laws of conservation (I guess simply paying tribute to history of their discovery), in higher classes we use various mathematical symmetries either directly or derive all possible laws from them mathematically. Same with exchange symmetry (which is simply a statements of identity of all particles of the same kind, so is just a definition) - the properties of bosons and fermions and their statistics mathematically follows from this definition (plus the definition of spin operator).

True that there are objects and rules in our universe which mathematical origin we have not figured out yet (so we know only then... but not if...). Say we don't know origin of most elementary particles, origin of gravitation, why some symmetries are more persistent (more universal) than others. But it was the same with many laws and objects just a couple centuries ago - we had electricity and magnetism (and optics) as separate phenomena with unknown origin, we had conservation laws but no explanation of why they are there and so on. So we make steady progress not just mathematically describing universe as it was in the past but mathematically explaining it as a mathematical (=logical) consequence of certain definitions and symmetries.

So, basicly physics is mathematics (applied one). And the tremendous success of physics (and success of application of it to subordinate disciplines - chemistry, geology, biology, meteorology, astronomy, cosmology, transportation, navigation, communication, entertainment, etc) is just due to its inherently mathematical (=logical) nature. That is why keeping track of definitions and keeping track of mathematical logic (what follows from what) is vitally important for understanding physics and universe.

Returning to your question about force and mass connection - mass is defined via mass standard, and then force is defined as the time derivative of momentum F=dp/dt.

Static equilibrium is NOT used to define forces, but rather to compare them with some "standard" force. Usually this "standard" force is the force of gravity which is defined not statically but in fact dynamically: W=mg=ma=dp/dt. Static equilibrium is then used to compare other forces with weight just because it is more convenient to compare forces when two accelerations are equal and oppositely directed (because then an object is moving with constant velocity which is easier to deal with than changing velocity; especially easy is to deal with objects when they not moving). Then we can calibrate newtonmeters and measure any other force as F=-W.

Hooke's law as you know comes simply from the fact that a solid is a bunch of atoms or molecules in equilibrium - first non vanishing Taylor term in restoring force upon displacement atoms from their equilibrium position is linear term. Not only linear but also all non linear mechanical properties of solids follow from mathematical consideration of atoms in equilibrium. Because of simplicity of linearity springs of varius kinds (especially shear type helical springs) are commonly used to compare various forces with the force of gravity (weight and mass standards), even despite that linearity range of elasticity (=validity of Hooke's law) is extremely small (less than 1%).

Boyle's law is even more obvious that Hooke's - it follows from momentum exchange during elastic collision of conserved number of particles with walls of container of variable volume (say, a cylinder with a piston). Here again a force (of the pressure on walls) is just the derivative of momentum of bouncing off wall particles (atoms, etc). By the way, if you change the volume of container rapidly enough (compared to average speed of bouncing atoms) then you won't get Boyle's, but you still will get ideal gas law.

Sincerely, Enormousdude 19:44, 22 August 2007 (UTC)

So, ED, I am a professional physicist: I know all about stuff like Noether's theorem and the kinetic theory (just to save you pointless typing). You write as if you have learned physics entirely by sitting in lecture theatres and libraries, without ever having set foot in a laboratory. At any rate, in my view you seriously underestimate the empirical component of physics. Experimental physics is certainly not an exercise in applied mathematics! (An opposing and equally blinkered position claims that "physics is measurement").

We agree that some quantities must refer outside the maths, including length and time. But I think you underestimate how many such quantities there are, and, in particular, that force is one of them. Consider geometry. As mathematics, "point", "line", "circle" etc are undefined symbols manipulated according to fixed rules. There are conventional interpretations for physical realisations. What happens when astronomical observations using these conventions contradict theorems of Euclidean geometry? According to Henri Poincaré (conventionalist philosophy), we should conclude that our procedures for making physical realisations are false, e.g. we should say that light does not necessarily propagate along geodesics in a vacuum. In fact, in GR we maintain our experimental definitions as much as possible and reject the geometry. It seems to me that you are a conventionalist with respect to the whole of physics. In principle, this is a self-consistent position but it is not how the physics community has usually operated. With your position, all empirical input to physics boils down to argument about whether the equations are correctly applied, since you do not allow enough quantities to have fixed empirical meanings to permit the equations to be falsified. At most you can say that the old theory becomes inconvenient.

As for these external referents. Clearly, it is not enough to define mass just to point at the standard kilogram. You need an agreed procedure for comparing the mass of an object of interest with the standard, to give a numerical measure of its mass. Thus for mass, too, there is no fundamental distinction between "definition" and "comparison with a standard". Force is best understood in exactly the same way. If one uses units like kilogram-force, this is obvious, and I hope you will agree that such measurements can be done using statics. In the SI system (among others), it is true that we have chosen to define the unit of force using Newton's second law. I suppose this is the core of our debate. For you, the definition of the unit is tantamount to the definition of the quantity, so the SI definition fixes the "meaning" of force. For me, it is just a convention for labelling the scales of balances. And like many SI conventions, it obscures the underlying physics. Now, I specifically asked you about inertial mass. How do you compare the inertial masses of two objects, other than by comparing their accelerations under a known force? In practice, of course, we usually rely on the equivalence principle and compare gravitational masses instead.

Finally, you entirely miss my point about Boyle's and Hooke's law. Let me be explicit: if the one true definition of force is F=dp/dt as you claim, how did Boyle and Hooke (not to mention Archimedes) come up with quantitatively correct force laws without knowing the definition of the quantity they were measuring? The microphysical explanations are quite irrelevant to this question. PaddyLeahy 11:42, 23 August 2007 (UTC)

Sorry for the delay - plenty of work in the beginning of new semester (to make sillabi, design tests/quizzes, assign h/w, etc). Indeed, I learned a lot in lecture halls and doing h/w problems, but I am experimental physicist by occupation so I know all about observations and measurements.

"Empirical component" of physics is of course nesessary component and a very important one. The reason being is that math itself is much more rich than physics. By other words, one can create a variety of non self-contradicting rules, but some of them may never correspond to any observable phenomenon or object (despite being correct). For example, we can built mathematically self-consistent rule of vector multiplication (say, we define a scalar product of two vectors A and B as the inner product of their corresponding components) for a space with any number of dimensions. Say, in for 5 dimensions it is A1B1+A2B2+A3B3+A4B4+A5B5. But 5-dimensional scalar product is not applicable to our universe because we have only 3 (spatial) dimensions. Should we then discard this product as non-existent and declare it non-legitimate mathematical object? Of course, not. Some other universe(s) may have 5 or more spatial dimensions and there 5-d scalar product is applicable. So to see which mathematical rules are applicable to objects in our universe we have to take measurements. This is where the distinction between mathematics and physics is: physics is only small part of mathematics, namely the part which is applicable to our universe. That is why I refer to physics as being "applied mathematics".

Measurements are also important when we don't know accurately enough relative strength of several competing contributions from different phenomena, or don't know accurately boundary conditions or initial conditions, or when experimenting is much less expensive than accounding for many complex factors involved.

About inertial mass. From observations we know that there is such property of matter as inertia. To quantify this property we introduce inertial mass as a measure of inertia. True, we then experiment with springs applying "spring stretched to the same distance" to unknown mass and measure mass's acceleration to compare it to the acceleration of "test mass" (=1 kg mass standard). Then we notice that twice amount of matter has exactly twice less acceleration (being acted upon by the spring stretched to exactly same length), so we then state second Newton's law as a constant product of mass and acceleration. But because we have not defined force yet, we do it right then - calling this product (=ma) by a new symbol F and writing F=ma as the definition of what we were incoherently calling by a word "force" (but without accurately defining it) before. If you are in classic mechanics class then we call the derivative dp/dt by the name "force". So, from observations we know that there is such property of matter as inertial mass and that this property is directly proportional to the amount of matter (twice much number of atoms of one kind has twice much mass). But we can say nothing about force (and it's property) from any number of observations BEFORE we define it. Do you say you consider marks on a spring scale to be the definition of force? I don't. It is very common misconception to rigidly relate force and spring. Force is not a fundamental quantity (and never was) - meaning it was never considered to be undefinable via other quantities. And indeed, it is easily definable: F=dp/dt. There are only 3 fundamental quantities in mechanics: time, space, mass. So, no, force is NOT a quantity we shall point a finger to (as mass, for instance). If you say that a force is a fundamental quantity too, then where is the force standard? There is none. If you feel that dp/dt is NOT the definition of a force, then tell what is (the definition)? And if you think that definition of force is "something which pulls" or "something which pushes" (I have seen such sloppy "definitions" in some textbooks) then obviousely my hand is a force - it can push and pull. If a force is defined as "influence which accelerates body" (there is such lousy "definition" also in some introductory textbooks) then obviousely work becomes a force, as well as gravitational mass too (mass pulls and accelerates nearby bodies). Also defining force as a "push" or an "influence" gives no unit to the proposed quantity F. Indeed, what units does "push" or "influence" has?

So, definitions of all compound quantities (force, work, energy, temperature etc) should be mathematically accurate and must be done via fundamental quantities which in turn should be defined via standards (pointing onto a "mass interval" and time/space intervals, and descriving a procedure of comparison/calibration of all secondary standards via the prime ones). And this is exactly what we have in physics. Look up 1st chapter of any good textbook. And force is NOT listed among fundamental quantities.

The very first force students in physics learn is a gravitational force (weight). It is defined exactly as I said above - via acceleration (=acceleration of free fall): w=mg. In fact, the very definition of the unit of force - Newton is done via acceleration too: "One Newton is the amount of force that gives an acceleration of 1 m/sec^2 to a body with a mass of 1 kilogram". Then we compare unknown force (say, compressed spring reaction force) to known weight (say, to 1 Newton) and mark the blank scale of spring balance as "1 N", then "2 N", and so on. Then we use this calibrated spring scale to define other forces (say, friction force, surface tension force, Coulomb force, magnetic force, etc). So, the definition F=dp/dt=ma is the only definition of force in physics.

Sorry, have to run - have a class to teach. Will add a few words later.

Sincerely, Enormousdude 23:59, 4 September 2007 (UTC)

About Hooke's and Boyle's measurements. I am not a historian to accurately find from original publications what exact definition of force (and pressure in Boyle's case) did they use. Most likely both used weights (attached to a spring in Hooke's experiments and placed on a piston in Boyle's measurements) - for which they assumed that doubling attached mass resulted in double weight pulling this mass down (thus double force on a spring and double pressure on a gas in a cylinder under piston). If this is the case then they use the same definition of force F=w=ma=mg=dp/dt which Newton proposed shortly after their experiments, and which is the only definition of force available today in physics.

Sincerely, Enormousdude 16:22, 6 September 2007 (UTC)

Cosmological scale

A {{prod}} template has been added to the article Cosmological scale, suggesting that it be deleted according to the proposed deletion process. All contributions are appreciated, but this article may not satisfy Wikipedia's criteria for inclusion, and the deletion notice explains why (see also "What Wikipedia is not" and Wikipedia's deletion policy). You may contest the proposed deletion by removing the {{dated prod}} notice, but please explain why you disagree with the proposed deletion in your edit summary or on its talk page. Also, please consider improving the article to address the issues raised. Even though removing the deletion notice will prevent deletion through the proposed deletion process, the article may still be deleted if it matches any of the speedy deletion criteria or it can be sent to Articles for Deletion, where it may be deleted if consensus to delete is reached. If you endorse deletion of the article, and you are the only person who has made substantial edits to the page, please tag it with {{db-author}}. Cosmo0

I thing you are dealing with the wrong person. I did not edit the article "Cosmological scale". Sincerely, Enormousdude (talk) 20:10, 29 January 2008 (UTC)

dp/dt

what is this? btw, i appreciate your edits and your contributions to wikipedia and you will not know how helpful they have been to my understanding of physics. thanks. BriEnBest (talk) 07:40, 1 February 2008 (UTC)

This is a time derivative of momentum. Enormousdude (talk) 18:33, 21 January 2009 (UTC)

Do you believe that the electric force is a more fundamental force of nature than the magnetic force?

If not, you should stop making edits that strongly imply it is.

If so, could you please explain why you believe this, and what reliable sources support this claim? I've read Purcell's textbook and many others. I would enthusiastically agree with the claim "electric force without the magnetic force violates SR", and also with the claim "the magnetic force can be mathematically derived from Coulomb's law and SR." But neither of those implies that the electric force is more fundamental than the magnetic force. For example, starting with the magnetic force and SR, one can mathematically derive that there has to also be an electric force! Does that mean that the magnetic force is more fundamental? Obviously not. It's always interesting to know that you can mathematically derive some aspect of physics from some other aspect of physics, but that doesn't immediately answer the question of what is more fundamental than what...

In fact, every physicist knows that neither the electric force nor the magnetic force is fundamental. They're both emergent phenomena, from the more fundamental theory of Quantum electrodynamics. Both the electric and magnetic forces are classical-limit consequences of QED. When you take the classical limit, you get the electric and magnetic force simultaneously, you don't get the electric force first and then later derive the magnetic force. So on a deeper level, one sees that the electric force and magnetic force are equally-(non)fundamental laws of physics.

A lot of the time it makes sense, as a pedagogical matter, to talk about the electric force first, since the math is simpler and the physics is more intuitive, and then show that if you're willing to believe that both the electric force and SR are true, then you have to also believe that the magnetic force is true and has the F=vXB form. Purcell does that, lots of teachers do that. But after learning it that way you shouldn't get carried away and think that, as a matter of true physics (not physics pedagogy), the electric force is a more basic and fundamental force in the universe than the magnetic force. --Steve (talk) 21:27, 21 January 2009 (UTC)

Electric and magnetic field are not symmetric. The source of electric field is an electric charge: div E = 4πρ , but what is the source of magnetic field - magnetic charge? No: div B = 0. Enormousdude (talk) 18:32, 26 January 2009 (UTC)

I agree, they're not symmetric. The "sources" of an electric field in classical electromagnetism are electric charges and changing magnetic fields, while the "sources" of a magnetic field in classical electromagnetism are moving electric charges and changing electric fields. I don't see how that implies that either of them is a more fundamental force of nature. In reality, we know that they're two different consequences of the existence of photons (and virtual photons) in quantum electrodynamics, and you can't discuss the fundamental nature of electricity or magnetism without discussing it in quantum electrodynamics. --Steve (talk) 19:57, 26 January 2009 (UTC)

Define electric field and magnetic field (obviousely that without clear definitions we do not understand what we are talking about, let alone discuss origin/fundamentality, etc). Enormousdude (talk) 20:33, 27 January 2009 (UTC)

The electric and magnetic fields are the fields E and B. In classical electromagnetism, they're vector fields, in reality they're quantum fields. You can measure [the expectation value of] both of them simultaneously by putting down a test charge and measuring the force on it as a function of its velocity, you can measure just E but putting down a stationary test charge and measuring the force on it, and you can measure just B with a compass. They're the things that are discussed in every electromagnetism course. That's what I'm talking about, nothing fancy. That's what you're talking about too, right? --Steve (talk) 21:09, 27 January 2009 (UTC)

Well, I meant accurate mathematical definitions E = ..., B = ... (as you must well know, in physics we define every quantity via fundamental physical quantities - see,for instance, first chapter of any introductory physics text). Without such definitions we have no idea of what we are going to talk, especially about magnetic field B. Enormousdude (talk) 20:39, 29 January 2009 (UTC)

OK, here's a definition, albeit restricted to classical physics: The electric field (at a given location and time) is E=F/q, where F is the electric force on a stationary point charge of magnitude q. The magnetic field (at a given location and time) is the unique vector B such that the torque τ on a stationary ideal magnetic dipole with moment m is τ=m×B. Is that clear enough for you? --Steve (talk) 21:12, 29 January 2009 (UTC)

Incorrect - you can't define magnetic field via "magnetic" dipole. This is called "circular definition" - you define an object (or subject) via itself! 161.28.196.47 (talk) 18:14, 13 March 2009 (UTC)

I've read the first chapters of many physics textbooks, and I've never seen "accurate mathematical definitions E = ..., B = ..." which do not (circularly) make reference to either electric charges, magnetic dipoles, or magnetic materials. If you have such a definition, please go ahead and tell me, I'm happy to use it so long as it's correct. --Steve (talk) 01:06, 14 March 2009 (UTC)

WP:PHYS

Hi, I noticed that you had some interest in physics. Might I interested you in joining WikiProject Physics? Headbomb {^ταλκ_{κοντριβς} – WP Physics} 06:09, 1 March 2009 (UTC)

I don't have time - I do research, present (at professional meetings), publish, teach, manage my students, buy real estate, etc. Enormousdude (talk) 18:20, 31 March 2011 (UTC)

What's with the destruction of mass thing, again??

Mass is conserved in special relativity. See mass in special relativity. That means mass remains the same in closed systems, over time, and across reactions. "Matter" may not be conserved, but matter has a an uncertain definition. So please don't foul up the mass-energy equivalence article with statements which are only true in non-closed systems, or true for MATTER but not mass. SBHarris 18:30, 3 March 2011 (UTC)

Incorrect. You don't understand the difference between conservation and invariance. Mass is invariant vs. shifts in velocity but not conserved quantity. Annihilate electron with positron - and all their mass is gone.

Enormousdude.

No, not unless you let it out of your system! This is a very simple concept in physics and you'd do well to learn it. Read mass in special relativity where this is explained. Read Taylor and Wheeler's Spacetime Physics chap 7. or one of any number of texts. In SR, the mass of closed systems is conserved (constant) over time, and with respect to interactions (including annihilation). Which is not surprising, since the energy of systems is conserved over time, also. Energy of systems is not invariant with respect to Lorentz transformations (it changes as you pick different frames), but mass of systems IS invariant, which is why it's called invariant mass. Mass is the Minkowski norm of a Lorentz 4-vector, the E,p 4-vector. So observers in different frames don't agree on the energy of a system, but they do agree that this energy doesn't change when there is a system interaction. They do agree on the system mass, which is both conserved AND invariant. Energy is only conserved (over time), but NOT invariant with respect to different Lorentz frames.

Two photons do have a mass unless they're travelling in exactly the same direction. Which is one reason why single particles like the neutral pion cannot decay to one photon. If electron and positron annihilate, the mass of this system of 2 resulting photons is exactly what it was before the annihilation (it is 1.022 MeV/c^2). Mass cannot be destroyed in SR-- it can only be moved.

Of course, some have wanted to define mass as E(relativistic)/c^2 (Tolman's so-called "relativistic mass"), in which case it has all the properties of total energy (it is not invariant any more, but it is still conserved over time). Thus, the system of two photons before and after anihilation has an energy that depends on the frame you observe from, but it whatever that energy is, it STILL does not change over time, as the pair annihilates. It is conserved, and constant for any given observer. SBHarris 00:57, 6 March 2011 (UTC)

I am sorry, but you need to study physics better. What is your specialty, by the way? You mix up two different quantities - mass and energy. What you call mass physicists call energy.

Anyway, tell me then - how much is a mass of a photon (say, one of the two 511 KeV photons left after annihilation of an electron and a positron)? Enormousdude (talk) 05:46, 7 March 2011 (UTC)

There are two different definitions of mass in common use: see mass in special relativity. Relativistic mass (invented by C. Tolman) is simply total energy/c^2. It's not very interesting because it has all the properties of total energy, so you may as well just use total energy. It was invented to make E=mc^2 always true, and avoid the energy momentum equation. It's probably a bad idea. In this definition of mass, a single photon has a mass of E/c^2, but that mass varies according to the observer's reference frame, just as does its energy. That's the type of mass you seem to think I'm talking about (I'm not). It is conserved (it cannot be destroyed any more than energy can, since it is simply E = E/c^2), but it is not invariant.

The more standard definition of mass (the one I like best) is what we call "rest mass" for single particles, or the invariant mass for systems (of which single particles are a sub-set). This mass is also conveniently m = E = E/c^2, but that is true only in the center of momentum frame of a system. In other frames where you see the system with nonzero net momentum, you must use m^2 = E^2 - p^2 to get the value of the invariant mass. Nevertheless, this measure of mass is BOTH conserved and invariant. This definition of mass for single photons is always zero since E = p for photons (thus m = E-p = 0), but one never obtains just a single photon from annihiliation of a particle that has rest-mass, so it's no problem. The pair of photons (occasional more) that one does get, has p=0 in the COM frame of the event, so the mass of the system remains 2E (where E is the rest mass of one electron) throughout.

When you ask me what is the rest mass of ONE 511 keV photon is, it is of course zero, but so what? If you're looking at ONE of the photons from an annihilation event, you've opened your system, so that the OTHER photon is now ignored. NOTHING is conserved if you open your system to mass and energy. Energy is not conserved, either! Annihilate 1.022 MeV of matter, and look at just one photon flying away, and all you see is half of that energy. This does not mean energy is not conserved in physics; all it means is that you didn't do your problem correctly, and opened your system. Energy is conserved in CLOSED systems over time. That is what we mean by "conservation." We don't mean "conserved under the property of mathematical addition". By "conserved" we mean "is the same over time, in a closed system, for any one observer." Conservation is just as true of mass, no matter what definition of "mass" we pick (even invariant mass). No, you can't get the total "mass" of a system by going to the rest frame of every moving part, then adding the masses all up. But you can't even get the energy of most systems that way, since you miss all the kinetic energy if particles are moving with respect to each other. Kinetic energy is a system property that isn't located in any given "place". So you can't just add up masses of parts of a system, each in their separate rest-frames, to give a total mass. Nor can you add up energies that way, to get a total energy (try it with photons and the energy of each photon is anything you like, since there is no rest frame for any of them). The whole procedure is just wrong, because it misses system properties, so you can't do it, either for photons or moving massive particles.

To answer your last question, my speciality is physiology, which means it's embarassing for me to have to teach you physics. But if you will not learn from anybody except a physicist, then go to the nearest full professor in your physics department and ask about the conservation of invariant mass and relativistic mass. Matter is not conserved, but all types of mass are. Or, read the text I cited, which is written by the same John Archibald Wheeler in Misner, Thorne and Wheeler, and is (believe it or not) a guy who knew what he was talking about when it comes to special relativity. Edwin F. Taylor does too. Whatever your credentials are, his are better. SBHarris 20:05, 7 March 2011 (UTC)

Take 1 light year box with a mirror (of a mass M>>me) in its center, annihilate electron and positron near mirror. What is the mass of the system right after annihilation? Now watch one photon reflect from the mirror and move in the direction, say, parallel to the other photon. What is the mass of the system now? Also, I followed your advice and asked a few professors in my department about definition of a mass. Well, all said it is the rest mass, not the relativistic one. And most of them agreed that mass is not conserved quantity (by definition of a mass). So your attempt to teach me a physics lesson was indeed embarrassing - just as you predicted :-). Enormousdude (talk) 18:33, 31 March 2011 (UTC)

Answer

We’re not done. I still have more physics to teach you. Let us take your thought problem.

1) The mass of the system of photons in your example depends on where you wish to place your system boundaries. If you draw them around the photons but don’t include the mirror at first, then later draw them newly to include the mirror after the impact, you’ve cheated, since obviously the system mass increases by the mass of the mirror M, just as a result of how you frame the problem. You don’t have a closed system. If you don’t have a closed system, not only is mass not conserved, but energy is not conserved as well, since you gain the rest energy of your mirror to your system when you re-draw your boundaries.

2) So, as you say, enclose the thing in a huge box. Let us include the mirror from the beginning and keep the system closed. We do the problem in the COM frame where it is easy (and we stay in that frame, so that energies all add up to invariant mass). That is the frame at rest with respect to the mirror, and for this to be the COM frame we must assume the e+ and e- are at rest with respect to the mirror also, but a bit removed in distance (is that okay with you?). Mass of system (invariant mass) is now simply M + 2m_e = M + 2m. I will use the small m for the electron and photon mass (the mass the photon adds to the system, not its rest mass). The total mass does not change through the coming reaction, as it is a conserved quantity.

System mass is also M + 2m after the photons annihilate, but before one of them impacts the mirror. (I will leave proof for you) After reflection from the mirror, one of the photons imparts momentum p to the mirror. How much? Well, the momentum of the left-going photon is -p, and the momentum of the right-going photon is +p. Once the right photon hits the mirror (p = 0 initially) the total momtum of the system on the right must till add to +p for the total p = 0. In the limit of M>>m and no energy transferred, the photon must transfer all of its momentum (actually, twice its momentum) and no energy, so it reflects off as –p (same now as its parallel partner) and the mirror gets momentum +2p. In this limit the mirror gets insignificant kinetic energy, even with an ellastic collision, so the reflected photon p and frequency do not change. The left momentum is -2p, and consists of 2 identical left-moving photons, each with momentum –p. The right momentum is +2p (all of it mirror momentum), but the right energy is still just the mirror’s rest energy Mc^2 (as it doesn’t move significantly after impact, so its v and kinetic E are neglectable). The left energy is 2E, all from photons. Since we’re still in the COM frame we can sum energies to get mass, so total M = M + 2E = M + 2m. Total system mass (system invariant mass) is still M + 2m. Not a very interesting problem, but it shows that system mass is conserved.

Now, Exercise for Student Enormousdude: shrink mirror M so it now is only a single electron, m, and Compton-scatter one photon off it, back in the direction parallel to its gamma photon mate. Show that now the two photons do NOT have the same momentum and energy after the scattering, even though they move in the same direction. However, momentum and energy are conserved, so show that the starting total system invariant mass (now “M” + 2m = 3m) remains unchanged, and is still 3m after the scattering. (Hint: you will find the photon scattered has only 1/3rd of the energy and momentum it started with).

Finally, “rest mass” only makes sense with single particles. It is conserved trivially since simgle particles remain themselves. For systems of particles, the “rest mass of the system” is its invariant mass (its total energy/c^2 in the COM frame where p =0) and this is conserved. I have no idea what you professors were thinking if they think invariant mass is not conserved. SBHarris 22:36, 31 March 2011 (UTC)

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Is there any chance that you know where to find the research papers of mostafa musharafa and sameera moussa?????????????? Also could you help me and write an article about Holdom particles?????????????????????????????????? THANKS — Preceding unsigned comment added by 41.68.50.100 (talk) 01:23, 15 September 2011 (UTC)

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