Talk:Theory of relativity/Archive 1

Archive 1

Archive 2

What is relative and why?

I think the reason for the word "relativity" should be explained on this page. What is relative, and why?

appears to be done.

---

Regarding a recent change to this article--I'm no physicist, but I always thought that relativity states that mass increases as velocity approaches the speed of light. Am I wrong on this?

---

Rest mass is a constant, but mass itself indeed increases in such a way that one can never accelerate an object beyond c.

Twin paradox

I'd like very much to hear about the twins paradox. Never been much comfortable with that one.

The basic non-symmetry is that one twin must accelerate to return to the other to compare ages face-to-face. Whilst they are in inertial frames, it holds. Dave McKee

Indeed, so it is not really a paradox (as is also the case for many so-called paradoxes). The twin that goes into the spaceship will be younger when arriving back, which is possible (and easy!) to describe with special relativity in the frame of the twin at Earth, but you'll need general relativity to describe correctly in the frame of the traveling twin, only to get the same result in a harder way, of course. -- JBC

---

It's a convention, not an absolute. In the way that mass is used currently in physics, it's an invariant between reference frames, i.e. it doesn't change with velocity. Mass = "rest mass", and "relativistic mass" is not used. There is an alternate formulation of relativity that uses the concept of "relativistic mass" because using it lets you keep using some familiar Newtonian mechanics (e.g. F=m_r a). But the invariant mass approach turns out to be somewhat easier to generalise into GR, so that's what basically everyone uses now. You'll still find "relativistic mass" in some textbooks (e.g., Feynman's Lectures on Physics) and in a lot of popularisations (I think it's in "A Brief History of Time"), but not in, say, graduate level textbooks and research papers.

For more on this, see [ http://www2.corepower.com:8080/~relfaq/mass.html]. Come to think of it, this should probably be written up in mass. -- DrBob

Time dilation

I remember reading once upon a time in some primary school-level book on relativity that if you approached a black hole you might never experience enterring it due to time dilation -- as you approach it your velocity approaches c, but time dilation reduces subjective time to the point you never enter it. Is this true, or is this just some mangled garbage? -- SJK

---

That happens according to a frame of reference far from the black hole. in your frame, you are swallowed in a finite time. (from what i remember)--AN

Galilean relativity?

Galileo was actually the fella who first proposed a relativity principle. I would like to (1) redo the article to review the various relativity principles or postulates. (2) Remove material that duplicates material in the Special Relativity and General Relativity entries and replace the removed stuff with links to them. (3) In short, do a more general treatment that links to more specific entries.

If there is no objection, I will replace the entry with my revision on the 16th of August, this month.

 - change of mind August 20 - I think I will do a separate article on The Principle of Relativity ( new article ).

---

Hilbert, not Einstein ?

Some things are missing here:

The formulas of special relativity ("Lorentz transformations") where first published by Woldemar Voigt in 1887 in his paper "Über das Doppler'sche Princip". FitzGerald, Lorentz and Larmor later published the same formulas. The name "Lorentz transformation" was chosen by Poincaré, but Lorentz prefered the to call them "Relativistic transformations" because he was aware that Voigt and FitzGerald found them before him.

The theory of special relativity is not by Albert Einstein but by Jules Henri Poincaré. In 1898, Poincaré stated that simultaneity is relative. In 1902, he discusses relative space and time in "Science and hypothesis". In 1904 during his speech in Saint Louis, Poincaré stated the principle of relativity for electromagnetism (The Galileo relativity is about mechanics). On July 5th, Poincaré published his paper ""Sur la dynamique de l'électron"". This paper contains the proof that the Lorentz transformations are a group. We know for sure (from the Einstein-Solovine letters) that Einstein has read "Science & Hypothesis" in 1902. There are also good reasons to believe that Einstein has read the 1905 Poincaré paper (Einstein made summaries & translations of several physics journals for the Annalen der Physik, including the journal "Comptes rendus" in which Poincaré published.)

The theory of general relativity is not by Albert Einstein, but by David Hilbert. Hilbert sent a pre-publication of his paper to Einstein. On November 18th, 1915, Einstein writes to Hilbert to confirm he has received the article. On november 20th, Hilbert submits his paper "Die Grundlagen der Physik. (Erste Mitteilung)" - it was published in January 1916. On November 25th, Einstein submits his paper "Die Feldgleichungen der Gravitation." - it was publised before the Hilbert paper on December 2nd 1915.

In 1763, Robert Joseph Boscovich sj. anticipated the "principle of Mach", "length contraction", "time dilatation" and "invariance" in the appendix of his book "A Theory of Natural Philosophy".

In 1782, George-Louis Lesage already knew that gravity propagates at light speed.

In the 1870s, Robert Stevenson (a.k.a. "Kinertia") anticipated the principle of equivalence.

In 1872, Camille Flamarion, published the "thought experiment of Einstein" in his book "Lumen".

in 1801, Johan Georg von Soldner anticipates the effect of gravitation on light.

in 1875, S. Tolver Preston predicts atomic energy, the A-bomb and superconductivity - based on the formula E=mc²

Here are the sources (and, very convincing, I'd say) that claim Hilbert's primacy in formulation of GR:

http://www.nobel.se/physics/educational/relativity/history-1.html

http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Einstein.html

A neutral view: http://physics.rug.ac.be/Fysica/Geschiedenis/HistTopics/General_relativity.html

This one bets on Einstein, but half-heartedly: http://www.bun.kyoto-u.ac.jp/~suchii/gen.GR8.html

And this one is emotionally charged against Einstein: http://home.comcast.net/~xtxinc/einstein.htm Mir Harven 07:55, 1 Sep 2004 (UTC)

---

move here

Unfortunately the result was a theory that was based on circular postulates (eg. time dilation is attributable to velocity, but velocity is distance divided by time) and one which, though it is widely claimed otherwise, ultimately conflicts with empirical evidence (eg. data from GPS satellites; Miller's, and Michelson-and-Gale's interferometer experiments of the early 20th Century that strongly suggest an ether; the objectively measurable, as opposed to observer-based status of so-called time dilation). It was without any reasoning that Einstein had assumed atomic oscillation to be the true measure of the flow of time, and the famous 'twin paradox' that followed from the fact that ageing is not a subjective process that depends upon reference frame, is in direct conflict with Einstein's basic postulates and reasoning, to the effect that Einsein's later general relativity must collapse also, and relativity, which is rejected by NASA and many prominent physicists, is of interest only in a historical sense. Famous anti-relatitivity papers include Guy Burniston Brown's What is Wrong With Relativity; Herbert Dingle's equally critical 'Science at the Crossroads' was published in 1972.

---

"In 1782, George-Louis Lesage already knew that gravity propagates at light speed." What is your basis for this wild claim? Considering that gravity waves are incredibly weak and were only detected in the 20th century (Nobel prize in 1993 to Taylor and Hulse, according to Wikipedia), how did Lesage determine this? Crystal ball? Tarot cards?

As for 3 of your other statements, I notice that you qualify them with the word "anticipates". I can anticipate the first contact with an intelligent alien race - does that mean you should start putting up monuments to me?

The only claim that may have any merit seems to be Hilbert's contribution to the general theory of relativity. There's a lively discussion about this in the article on Einstein. Clarityfiend 07:08, 26 February 2006 (UTC)

Synopsis

I agree this page should be a synopsis, in which the charcater of general principle of SR and its application inside ordinary matter should be apparent. Thus I reverted to the previous mention of these issues; please let me hear opinions.

---

This isn't generally accepted science.

Special relativity thus makes a general principle with applications in physics, chemistry, and even life sciences. It not only depicts relationships between the perspectives taken from loose moving bodies. Often together with quantum mechanics, special relativity is also employed to describe microphysical motions inside lumps of condensed matter, like pebbles and biological organs such as kidneys or brain. It, e. g., was of help to electroneurobiology researchers trying to explain physiological mechanisms that enact variations of attention, and disconnection states such as sleep and coma, as electric field-mediated relativistic effects in brain biophysics.

• • Hi, Roadrunner! You had avowed, "The only thing I care to reveal about myself is that I am a subscriber to Time Warner. Roadrunner." But here you seem also revealing to hate relativity physicists, one of whose more recent sources of revenues is biophysics. You're also contributing to keep students thinking that relativity is just concerned with heavenly matters. I don't believe that a Time Warner subscriber may harbor such bad sentiments, so please remake the paragraph, if you like, but kindly put the concept back on the entry - which becomes too much impoverished otherwise. David--200.42.95.188 17:38, 15 Oct 2004 (UTC)

• • • While Roadrunner comes back on changing the above paragraph, I'm reverting to its previous version.

---

I concur for reversion of this paragraph. Even if it is scientifically founded (I take no position on this question here), it is too particular an issue for a general article about relativity. --French Tourist 14:09, 16 Oct 2004 (UTC)

• • • Too drastic. Since Roadrunner did not yet edit the paragraph of her/his interest, I'm pruning it into a proposed version that keeps the concept (special relativity is being growingly used in basic biomedical research) and wait for her/his opinion. Cheers.

---

Hi. The users trying to add here the text about the influence of the special relativity in "brain biophysics" are doing the same at es:. They provide little or no evidence apart from their own works, and answered with insults and threats when questionned. We have blocked the article and currently we are trying to decide what to do. If anyone can read Spanish, please take a look at es:Discusión:Teoría_de_la_Relatividad. Thanks. --es:Usuario:Dodo

---

I don't know whether I'm wrong on this, but I thought that the theory of relativity also states that energy and mass are interchangeable depending on the speed? Can anyone enlighten me on this subject?

That's just a minor consequence of special relativity. The article on that has more on the subject. --Carnildo 06:43, 18 Jun 2005 (UTC)

Removed links

I've removed links to www.anti-relativity.com for the following reasons:

• The first sentence on the first page is an attack on the reader
• The first sentence in the "paradoxes" section is an attack on the reader's intelligence. Further, the author demonstrates that he doesn't understand either the twin paradox or the doppler effect with respect to light.
• The author confuses zero-point energy with aether.
• The forum only has three threads and four posts.

--Carnildo 17:52, 5 Apr 2005 (UTC)

Relativity Joke

I don't think this (well-known?) joke deserves a place on the main article page (others may disagree), but I thought I would add it here just in case:
Einstein's Theory of Relativity: Time appears to pass slower... when visited by relatives!

Law or theory?

The List of laws in science lists relativity as a law. Either this theory of relativity page should be changed to reflect this or that page be should be changed (if relativity isn't a law). DarthVader 23:57, 6 October 2005 (UTC)

Under physical law, laws of science are, among other things, "always true", "universal", and "eternal". Einsteinian relativity has problems with these, in particular in the quantum realm (see Quantum gravity) and over long timescales (see Cosmological constant). --Carnildo 00:19, 7 October 2005 (UTC)

Yes I agree. DarthVader 01:03, 7 October 2005 (UTC)

I have found the problem: Whoever created that list did not distinguish between categories and individual laws. In the case of relativity, the editors of that list seem to have had no idea of what the laws of relativity are. I have editted that list to clarify things a ways. --EMS | Talk 03:07, 7 October 2005 (UTC)

DAB page

I've reviewed this page and believe it should not be listed as a DAB page. Please comment. Thaagenson 22:09, 15 November 2005 (UTC)

I agree - it's not a dab it's an article explaining the term "Theory of relativity". I recommend removing the {{disambig}}.--Commander Keane 23:20, 15 November 2005 (UTC)

General relativity date

In the section about general relativity, it says that general relativity was first proposed by Einstein in 1916, then it says it was 1915. This doesn't make sense to me, so I would suggest that you clear that up.

relativity opposition

There are lots of people that don't believe in relativity, some widely known names too. Is there a list of figures and research programs on the wikipedia for anti-relativity research?

I know of no such thing in Wikipedia at this time, or at least not in an article focussed on relativity iteslf. At the least, it is not reference from category:relativity, nor is anything similar in category:special relativity or category:general relativity. I assume that you mean actual opposition to relativity theory itself instead of some variation on the theme such as may be found listed in classical theories of gravitation.

The place where you may find something related is List of alternative, speculative and disputed theories#Physics. Beyond that, if you know of such research programs then perhaps you can create an article on them. The subject, if done properly and with some respect both for the efforts to disprove relativity and for relativity theory itself (or in other words being more or less NPOV) would IMO be quite encyclopedic. --EMS | Talk 15:44, 17 January 2006 (UTC)

Please don't duplicate articles

I did a significant revert just now due to this page having come to contain a lot of text brought in from the special relativity and general relativity pages. Those details do not belong here. Instead this page is to direct people to the proper page based on their interest. Also, duplicating text means that it needs to be maintained in two places! I am not against some thoughtful expansion, but this must remain a high level, broad brush article to be appropriate and effective. --EMS | Talk 15:25, 17 January 2006 (UTC)

Merge proposal February 2006

It seems to me that the pages at Theory of relativity and Principle of relativity have evolved to the point where they could be merged: there are many duplications; and the reason for starting Principle of relativity -- the emphasis on Einstein's theories at Theory of relativity -- no longer holds, as each of those has been moved out into its own page. Ewlyahoocom 20:43, 11 February 2006 (UTC)

Strongly object - First of all, the de-emphasizing of Einstein's theories in this article was inappropriate, and I have undone it. Secondly, the principle of relativity far predates the theories of relativity, having been used in the formulation of classical mechanics. So the principle and the theory are really two seperate and encyclopedic subjects. --EMS | Talk 15:51, 14 February 2006 (UTC)

I there are no other comments forthcoming, I will soon remove the merge tags. I cannot see this proposal going anywhere. --EMS | Talk 01:09, 20 February 2006 (UTC)

I don't think we should merge. Freddie 02:32, 22 February 2006 (UTC)

Rewrite of intro & removal of talk of "classical theories"

I rewrote the intro since the current one had somehow come to describe "relativity" in a way that even includes Newtonian physics. Let's just say that this is most incorrect. Although Newtonian physics also uses the principle of relativity, as it does not include a locally constant and isotropic one-way lisght speed it is not in the venacular of physics a theory of relativity. I also got rid of the talk of previous theories on the behavior of light since that is best described in an article like the history of special relativity, but is only a distraction at the high level of this article. I also got rid of the {{expert}} tag: I think that this article is fine as is as a high-level review of the subject. It is much better to let the special relativity and general relativity article deal with the specifics of those theories, yet that tag also begs for people to expand this article. --EMS | Talk 15:46, 14 February 2006 (UTC)

Opposition to the "Opposition" section

User:GalaazV added to this article:

==Opposition to the relativity theories==

Main article: Aetherometry

There have been dozens of modern scientists that have pointed out internal inconsistencies and unwarranted assumptions of standard relativity theory ^{[1] [2]} and there was already advanced plausible alternative explanations ^[3] - which includes the model of a dynamic ether with density proportional to the density of any physical substance occupying the area of space concerned, increasing around large bodies such as stars and planets, acting as a refracting medium and affecting the speed of propagation of light and electromagnetic forces, etc. - for all the experimental data and astronomical observations currently cited in support of the special and general theories of relativity.

I find this text to be inappropriate to this article and not very well written. I am therefore going to revert it out. However, I will put a link to the anti-relativity article into the "See Also" section to replace this. --EMS | Talk 23:23, 14 February 2006 (UTC)

Thanks, that would be because my mothertongue is not English. Anyway, my intention is not to build a section or article about this subject, but just to point out that in different countries there are individuals with attention to current-day Physics (and other science fields as e.g. Geology) status and mainstream 20th century science established thought, although made possible so many advancements in technology (as in my Telecommunications field), is not not to prevail if found that is flawed (as mainstream thought during our western middle ages was proven to be). Regards, --GalaazV 23:44, 14 February 2006 (UTC)

Let me put it to you this way: You cannot place your ideas into Wikipedia at all until they have obtained some mainstream attention, and in any case you cannot showcase alternatives to relativity in an article on relativity. A discreet reference is one thing (which is why I added the anti-relativity link to the "See Also" section), but extensive discussion on alternative ideas inan article for a well established theory like relativity is off-topic and usually lacking in NPOV. Indeed, if Wikipedia had existed in 1908 (when special relativity became respectable), a relativity article back then would certainly have been expected to mention and cite the luminiferous aether but not to discuss it in detail. --EMS | Talk 17:20, 15 February 2006 (UTC)

I understand your point, but who knows if in the 1908's hipothetical Wikipedia, or earlier, a Theory of relativity article would have been much more welcome than the efforts made a few to explain in a decent article what Aetherometry brings and purposes (which was from the beginning subjected to constant and biased negative labeling, ad hoc deletions and final erasion; Talk:Aetherometry). Respect should be mutual: respect is not a subjective attitude, it is a required attituted when discussing so important issues and conceptions, it is not an attitude required only to have toward a "well established theory", but extensive to both approaches, and this was not the case. So, my editions here were highly discreet if compared to the brutality of other wikipedian 'mainstream science' users' editions at the earlier mentioned article. --GalaazV 19:23, 15 February 2006 (UTC)

"Wikipedia is not a soapbox. ... Wikipedia is not an indiscriminate collector of information". I hear you on the issue of respect, but you need to respect Wikipedia and its mission. The purpose of this project is to document current human knowledge. The standards for inclusion in Wikipedia is based on part of the NPOV standard, which states that "[i]f a viewpoint is held by an extremely small (or vastly limited) minority, it doesn't belong in Wikipedia (except perhaps in some ancillary article) regardless of whether it's true or not; and regardless of whether you can prove it or not. In other words, views held only by a tiny minority of people should not be represented as though they are significant minority views, and perhaps should not be represented at all." That is why your contributions are getting bounced. Also, do not expect any sympathy from myself on this issue. If you look at my user page, you will see that I am engaged in my own original research, and have very much chosen not to attempt to document it in the article space. Unlike others, I see no need to treat my own unproven viewpoints as some kind of God-given fact, nor to treat Wikipeidia as my personal billboard. --EMS | Talk 06:07, 16 February 2006 (UTC)

Relative realisation

When an astronemer in a ship with relative speed does not note any change in mass or time unless n untill he doesnt look out of his window....

then how come he has to increase the thrust to reach lights speed cuz according to his instruments his ship weighs the same amount when he was stationary?

mass becomes infinite according to the observer so why and how would the traveller get effected by increased mass and would be stopped from reaching lights speed?

vijay(vijay.rajonline@gmail.com)

—Preceding unsigned comment added by 61.17.44.135 (talk • contribs) (Dishnet DSL Limited; geolocated near Hyderabad, India)

I'd love to respond here, but Wikipedia is not USENET. I advise you to place this query onto the newsgroup sci.phyiscs.relativity. --EMS | Talk 04:06, 27 February 2006 (UTC)

Vijay, it's a bad idea to put your email in a Wikipedia talk page because you are likely to get spammed (the spambots troll through Wikipedia looking for email addresses). If you register as a user, you can set an option which allows other registered users to email you, without knowing your email address. ---CH 06:16, 16 May 2006 (UTC)

Expand the article?

I was dissapointed at the lack of size and depth of this article. I may try to expand it.

Benjaminstewart05 15:15, 29 April 2006 (UTC)

Be careful about this. The last time someone tried to expand it, all that they did was to import large pieces of the special relativity and general relativity articles wholesale. That does not work, since duplicate texts tend to become unsychronized fairly quickly in Wikipedia.

If there is something more that you feel needs to be said about relativity theory as a whole, then feel free to add it. Otherwise, I strongly counsel you to let the specific article on special relativity and general relativity do the in-depth describing of those theories. --EMS | Talk 16:38, 17 May 2006 (UTC)

Vandalism by optus.com.au anon

An anon using IP 61.88.131.189 (talk · contribs) registered to OPTUS COMMUNICATIONS in North Sydney, New South Wales, Australia tried to insert a silly hoax.---CH 04:21, 5 June 2006 (UTC)

"Sorcerer"'s call for a "concerted, concentrated and united front"

"Sorcerer"'s post

—Preceding unsigned comment added by 62.56.93.135 (talk • contribs)

Hi, 62.56.93.135, yes we know :-/

For others: the cited post (which was crossposted to a half dozen or so UseNet groups) is by someone using the handle "Sorcerer", who also uses the handles "Androcles" and "Hexenmeister", and who recently started to edit the Wikipedia as Der alte Hexenmeister (talk · contribs · block log). The kind of namecalling to which this individual has been prone in Usenet (the cited post is a typical example) would of course not be tolerated at WP, so I am cautiously optimistic that this isn't really anything to worry about too much.---CH 12:37, 17 June 2006 (UTC)

For others: I have requested the WP board of trustees to have Schaefer blocked from editing, I shall now make the same request for Hillman to be blocked.

Der alte Hexenmeister 00:57, 18 June 2006 (UTC)

Hexenmeister/Sorcerer/Androcles, please see WP:DR for a summary of dispute resolution procedures at WP. Note that this and other articles suggest ways to avoid escalation of disputes, which seems reasonable. In that spirit, please see Wikipedia:Requests for comment/Der alte Hexenmeister. If you add a polite comment at the bottom of Wikipedia talk:Requests for comment/Der alte Hexenmeister, I will move it to the proper place on Wikipedia:Requests for comment/Der alte Hexenmeister; I suggest this because I think you are having some trouble formatting your comments in a way which helps keep talk pages readable. Please see also WP:AGF. TIA ---CH 06:09, 19 June 2006 (UTC)

merger proposal

The current version of "relativistic mechanics" outright duplicates this article. I will convert it into a redirect to this page now. I cannot see it as being controversial under these circumstances. --EMS | Talk 14:49, 26 June 2006 (UTC)

2 assumptions for SR => 1?

How about rewriting the end of the section on SR to read:

The great strength of special relativity is that it can be derived from a single premise:

• The laws of physics are the same in any inertial frame of reference. This means that the laws of physics observed by a hypothetical observer traveling with a relativistic particle must be the same as those observed by an observer who is stationary in the laboratory. In particular both observers see Maxwell's equations (which predict the speed of light to be 299,792,458 meters per second) obeyed; so the speed of light is the same, relative to all inertial observers.

It would make SR seem a lot less mysterious and ad hoc. --Michael C. Price ^talk 20:18, 4 July 2006 (UTC)

Updated as indicated. Sorry if this clashes with any off-line re-writes in progress. Overwrite as you wish. --Michael C. Price ^talk 22:25, 8 July 2006 (UTC)

I have removed the business of SR being derivable from just one postulate. Technically, this may be true, but it is not common knowledge. Furthermore, you are asking the reader to consider the meaning of Lorentz invariance, which I find less than proper since that is an advanced concept. Ideally, this article should be a breif overview of what the theory of relativity is (or rather what the theories are). --EMS | Talk 01:24, 11 July 2006 (UTC)

See Talk:Principle_of_relativity#merge_with_theory_of_relativity; this article will probably become a disambiguation page. When the text is ported over to principle of relativity I believe the extra paragraph will make more sense. (BTW not being common knowledge is not a good reason for deletion -- indeed I would have thought that was a good reason for inclusion, since it logically follows from the previous paragraph.) The reader doesn't have to understand lorentz covariance to understand the superiority of a system derived from 1 postulate rather than from 2. I propose that we reinclude it for the moment and take this discussion to the talk:principle of relativity page after the merge above is complete. --Michael C. Price ^talk 05:26, 11 July 2006 (UTC)

I have moved all the material to principle of relativity, in addition making some minor changes: Indian relativity created, link between lorentz covariance in GR and SR clarified. Newtonian mechanics tie in with with Galilean transformation not yet made. This article is now a disambiguation page.--Michael C. Price ^talk 06:07, 11 July 2006 (UTC)

Vote for deletion

Frankly I don't understand why this article exists at all. There's no such thing as the "theory of relativity". There's a theory of spacetime symmetry called "the special theory of relativity" and a theory of gravity called "the general theory of relativity", but those are inappropriate and misleading names that we're stuck with for historical reasons. The only reason Wikipedia should even have an entry for "theory of relativity" is that it's a term that people use, sloppily, when they should use something more specific.

My proposal:

• Relativity should be a disambiguation page, i.e. it should redirect to Relativity (disambiguation), not to Theory of relativity.

Agreed. --Michael C. Price ^talk 13:02, 5 July 2006 (UTC)

Agreed. The theory is and will always remain ambiguous, always controversial, although I'd call it "inconsistent".

It is circular and contradictory for Einstein to use the term c+v

 (http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif)

to derive c = (c+v)/(1 + v/c) , "with the help of the equations of transformation developed in § 3"

  (http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img76.gif)

even if he changes "v" to "w" to hide his spoof. (forgot to add signature on previous edit.) Der alte Hexenmeister 23:10, 11 July 2006 (UTC)

• Theory of relativity should be a disambiguation page with fewer entries (only Special relativity and General relativity). This reflects common usage, if not common sense.

Also Galilean invariance = Galilean relativity. But I think there is enough material common to Galileo's and Einstein's x2 relativities to justify it being more than just another disambiguation page. It's possible to speak about the concept of relativity without specifying any theory in particular. (Relativity is a horrible, misleading term, invariance is much better, but that's history.)--Michael C. Price ^talk 13:02, 5 July 2006 (UTC)

• Put information about the theories (like MichaelCPrice's suggestion) in their respective articles.

-- BenRG 12:38, 5 July 2006 (UTC)

I'm not sure these proposals would help the average person find out more about "the theory of relativity". They might help those who already know a lot about it, but then, they wouldn't be searching to find out more information in the first place. --Dweller 13:06, 5 July 2006 (UTC)

Granted we have to think very carefully about what approach will help the average reader. My suggestion is that we do NOT say that SR rests on the assumption of the constancy of the speed of light to all observers, since it poses the natural question of "why the hell should we assume that". That SR is often presented this way is unfortunate and is probably why the field attracts so many cranks. I suggest that SR be presented as a natural outgrowth of Galilean relativity, extended from mechanics to include electromagnetism. BTW, did Galileo actually write down the Galilean transforms, or did he just enunciate the principle with his "below deck" example? --Michael C. Price ^talk 13:23, 5 July 2006 (UTC)

Comment Sorry, I understood your first sentence, but then you lost me, around the point you wrote "My suggestion is that we do NOT say that". Thereafter, you weren't addressing my point at all. And if you were, I didn't understand a word of it. All I'm saying is that people looking for info about this topic will type in "Theory of relativity" or "relativity" and expect an article about Einstein etc. And, guess what, that's what they get currently. --Dweller 14:10, 5 July 2006 (UTC)

Sorry for the confusion, yes I wandered from addressing your point to addressing the issue I raised in the previous section. As for your final comment, yes most people will expect to see an article solely about Einstein when they type in "relativity" -- well time for them to learn something new :-) --Michael C. Price ^talk 15:36, 5 July 2006 (UTC)

As far as I know he just stated the principle. In any case, you've convinced me that the principle of relativity deserves its own article. But it already has one (principle of relativity). So my new proposal is:

• Make Relativity and Theory of relativity into disambiguation pages, pointing to Principle of relativity, Special relativity, General relativity, and, in the former case, various other stuff like the Escher lithograph.

• Revamp Principle of relativity, folding in the current content of Theory of relativity (and Galilean invariance, I suppose). I volunteer to do this, as I have a fairly good idea of an outline for the article.

-- BenRG 13:57, 5 July 2006 (UTC)

Sounds OK. Be bold! --Michael C. Price ^talk 15:36, 5 July 2006 (UTC)

I'm not quite sure what is being achieved with all this. The current Theory of relativity page suits me fine, but I do not want it expanded any more. (I do admit that it is already a effectively a disambiguation page.) As for principle of relativity, we very much need to condense the relativity-related parts of that. I find them to be poorly written and the general relativity related part isn't even correct. My suggestion is to do the merge with Gallilean Invaraince and fix what's there. --EMS | Talk 16:24, 5 July 2006 (UTC)

OK, I've made a stab at clarifying the relationship between Galilean, Special and General relativities. See what you think. --Michael C. Price ^talk 23:11, 8 July 2006 (UTC)

Some more changes completed. Updated the GR intro and pointed Galilean invariance and Galilean relativity together. I think the principle of relativity can now be merged into theory of relativity. --Michael C. Price ^talk 10:43, 9 July 2006 (UTC)

Relativity is now a straight disambiguation page that refers to primarily special relativity, but also general relativity, galilean relativity and theory of relativity, before listing the non-physical meanings. --Michael C. Price ^talk 12:29, 9 July 2006 (UTC)

I have undone the redirect. The result is just plain ugly. Someone looking for information on the "theory of relativity" does not care about all of the other uses of the term "relativity". As a short, quick sketch of relativity theory, this is an excellent page. It answer's its question: "What is the theory of relativity"? If you want details, you go to the pages on the individual relativity threories. It may sound silly to you, but as a "semi-disambuguation" page, this works very, very well. --EMS | Talk 14:24, 11 July 2006 (UTC)

At the cost of maintaining the two pages' subsections in line with each other. They've already diverged. Urghh... We obviously have different ideas of ugliness. --Michael C. Price ^talk 15:01, 11 July 2006 (UTC)

Theory of relativity is now factually incorrect, since Galilean relativity is a theory of relativity. Granted, most non-physicists are not aware of this, but shouldn't we educate them? --Michael C. Price ^talk 15:05, 11 July 2006 (UTC)

Counter POV

1. The laws of physics are the same for all observers in uniform motion relative to one another (Galileo's principle of relativity)

the fact that insanity is possible immediately debunks that :) —Preceding unsigned comment added by 67.189.29.138 (talk) 14:07, 4 December 2008 (UTC)

It is a LIE to claim SR is based on only two premises. At the heart of SR is Einstein's definition of time, "we establish by definition that the "time" required by light to travel from A to B equals the "time" it requires to travel from B to A, which is vastly different from common sense or Newton's definition and should be included as a clearly stated third premise.

It is a LIE to claim the speed of light in SR has a value, it clearly given by Einstein as the distance traveled from A to A in time t'A-tA in the form 2AB/(t'A-tA) = c which Einstein ASSUMES, claiming it to be in agreement with experience. Reference "On the Electrodynamics of Moving Bodies" by A. Einstein. The point of view given is not neutral.

Der alte Hexenmeister 23:56, 8 July 2006 (UTC)

You obviously didn't read the article. First, SR derives from one assumption, not two. Second, Einstein didn't assume C from nowhere, it came from Maxwell's equations (as stated in article). Third, your definition of time is compatible with Newton's. Fourth, calling some one a liar is in conflict with Wikipedia:Assume good faith. I shall revert your change. --Michael C. Price ^talk 00:09, 9 July 2006 (UTC)

You obviously didn't read Einstein's "Zur Elektrodynamik bewegter Körper" where he clearly states 2AB/(t'A-tA) = c. Therefore I dispute c as the speed of 299,792,458 meters per second, Einstein clearly states "die Lichtgeschwindigkeit in unserer Theorie physiaklisch die Rolle der unendlich großen Geschwindigkeit spielt." (the velocity of light in our theory plays the part, physically, of an infinitely great velocity) I don't know what your problem with the truth is, this is an encyclopedia, not a vehicle for you to prat around with voicing your own non-neutral opinions, Price. Nor have I called you a liar, I said the article was a LIE. Der alte Hexenmeister 15:18, 9 July 2006 (UTC)

I cannot accept a translation from someone who screams hysterically that the article is a LIE. Find the quote you dispute at this translation of Einstein's exposition:[4] and we can have a debate. --Michael C. Price ^talk 16:28, 9 July 2006 (UTC)

Better still, try this translation.[5] which shows that Einstein is talking about the addition of velocities and how c cannot be reached. I fail to see how quoting Einstein is going to disprove Einstein  :-) Also you should note that Einstein regarded his theories as extending Newton's, not overturning them.--Michael C. Price ^talk 16:53, 9 July 2006 (UTC)

I am not interested in debating relativity with you on these pages, Price, my concern here is factual reporting Einstein's relativity, not yours or Schaefer's. Nor am I interested in what you fail to see, that is your problem. Visit an optician if you are having trouble seeing, and when you have new spectacles or contct lenses try this translation: [[6] since you cannot accept mine. It says: "we establish by definition that the "time" required by light to travel from A to B equals the "time" it requires to travel from B to A", which remarkably similar to the one I gave. It should be, I copied it. If you want a debate, Usenet is available, and quit screaming hysterically that you cannot accept the translation I gave, I used the translation you suggested. BTW, Einstein devotes a chapter (chapter 7) to the recognised incompatability between his two "postulates" in Relativity: The Special and General Theory. Obviously you didn't read it, you are having trouble seeing, or you may have noticed the incompatability went from "apparently irreconcilable" to "Apparent Incompatability" in 15 years after he was severely criticised but maintained his pet theory. It is a neat trick to claim only one. And a LIE.

Der alte Hexenmeister 21:29, 9 July 2006 (UTC)

---

From WP:NPOV#Undue_weight:

If a viewpoint is held by an extremely small (or vastly limited) minority, it doesn't belong in Wikipedia (except perhaps in some ancillary article) regardless of whether it's true or not; and regardless of whether you can prove it or not.

My view is that the view of Der alte Hexenmeister (talk · contribs) does belong to such a limited minority, and that the {{NPOV}} tag is therefore inappropriate for this page. However, IMO there are two proper ways of removing such a tag: Either the poster removes it or a consensus of the other editors has it removed. I therefore call for a poll on removing the NPOV tag and for keeping it off in order to establish that said consensus exists. --EMS | Talk 17:36, 9 July 2006 (UTC)

• Support --EMS | Talk 17:36, 9 July 2006 (UTC)
• Support --Michael C. Price ^talk 17:44, 9 July 2006 (UTC)
• Support --Tailpig ^talk The statement made by Der alte Hexenmeister (talk · contribs) that light doesn't have an actual speed I understand to be technically correct. However, for reasons of clarity, the distinction shouldn't belong in this introductory article. The current definition of the speed of light in meters per second is good enough and not worthy of an NPOV tag. 18:13, 9 July 2006 (UTC)

Please note: If you don't want your writing to be edited mercilessly or redistributed by others, do not submit it.

Your political shenanigans and pratting around (as User:Connolley calls it) are not science, you are harming wikipedia with vandalism. I have pointed out three LIES above, and lies are considered as vandalism by wikipedia. As Tailpig has correctly stated, and for reasons of clarity, it should be known to the general public that in the Theory of Relativity the speed of light is undefined. The current 4th LIE is a denial of Einstein's own words:

"These two postulates suffice for the attainment of a simple and consistent theory of the electrodynamics of moving bodies based on Maxwell's theory for stationary bodies." The so-called "Lorentz" transformations were derived by Einstein based on his third premise.

http://www.androcles01.pwp.blueyonder.co.uk/Rocket/Rocket.htm

If necessary the matter will go to arbitration if it cannot be resolved here. I will not casually stand by and see the history of physics rewritten by popular vote. Either this is to be Einstein's relativity or it is to be relativity by popular opinion, and if that is what wikipedia wants then let it go to arbitration and wikipedia can decide. My opinions are not germaine to the facts and neither are yours, gentlemen. Der alte Hexenmeister 21:19, 9 July 2006 (UTC)

When you learn the difference between a lie and a mistake and stop violating Wikipedia:Assume good faith we can have a debate. Not until though -- although from the look of your arguments at talk:special relativity it doesn't seem as if there will be much point. --Michael C. Price ^talk 22:48, 9 July 2006 (UTC)

Do you agree to a mediator, or do you admit your mistake and will you voluntarily correct it without mediation? From your tone that seems unlikely, you have yet to show good faith, removing not my edit of the content (for there was none), but my announcement of a dispute as to yours and Schaefer's non-neutral PoV. I am not interested in discussing the rights or wrongs of relativity with you here, Price, that can be done through Usenet if you are interested in learning. I can teach you the subject there. There should be no debate as to facts. Here, the issue is FACTS and you have not checked yours. That is the issue to address. If it was a mistake to claim one postulate/premise/guess/lie-by-Einstein was sufficient, correct it and the matter is resolved. If it was a mistake by you or Schaefer to claim the derivation of the cuckoo transformations Einstein blames on Lorentz doesn't depend on Einstein's personal definition of time, correct it. You don't have to use my words, which have a clear non-neutral point of view, use Einstein's words. If it was a mistake to claim the speed of light is circa 300,000 km/sec, correct it. Other men greater than the pygmy Einstein found that value, giants like Albert Michelson who discovered there was NO aether. This is definitely and unmistakably a lie: "You obviously didn't read the article. First, SR derives from one assumption, not two." -- Price. That is NOT a mistake. I very obviously DID read the article. It's time YOU understood the difference between a mistake, a lie and a personal point of view, and quit taking a combative stance by removing my dispute notice, which against wikipedia policy. We are not hear to discuss Einstein's mistakes/blunders/ignorance/incompetence, we are here to write FACTS as they ARE. Fail and this is the next step: http://en.wikipedia.org/wiki/Wikipedia:Mediation It that fails, then arbitration. Failing to abide by arbitration will get you blocked. Your call.

Der alte Hexenmeister 23:45, 9 July 2006 (UTC)

---

Androcles/Hexenmeister - If you wish to do the initial legwork for the Request for Arbitration, I will be most appreciative of it. Doing all the setup for those things is such a bother, after all, and that is part of the reason why one has yet to be started against you. Just be aware that it is very easy to turn the initial request from you into a request against you. --EMS | Talk 23:11, 9 July 2006 (UTC)

RfC

BTW - There is an ongoing RfC on Der alte Hexenmeister at Wikipedia:Requests_for_comment/Der_alte_Hexenmeister. People are invited to add their own observations and comments to this document. (It may become the basis of a request for arbitration). --EMS | Talk 17:46, 10 July 2006 (UTC)

"Special Relativity for little kids"

User:Tosayit added to this article a section called "Special Relativity for little kids" which read as follows:

The easiest thing to understand about special relativity is that nothing remains constant...except for the the speed of light. Mass increases with speed, with a mass of infinity for an object other than photons (which weigh nothing when not moving) at the speed of light. Length and time approach nothing when at this speed too.

I have removed this section since it is a distraction. It also over-simplifies the theory to the point of near uselessness. IMO this write-up only proves that special relativity is not for little kids. --EMS | Talk 23:21, 9 July 2006 (UTC)

Your OPINION and tyranny noted. Schaefer's opinion isn't Einstein's relativity. The arbitors will be informed of that fact if it comes to it. Take enough rope, Schaefer. Der alte Hexenmeister 23:53, 9 July 2006 (UTC)

Indian relativity

I have copied the section over from principle of relativity, prior to possibly redirecting principle of relativity to here. I've left a message on their talk page asking what they thought of such a move. If no one objects I suggest we do it in a day or too. --Michael C. Price ^talk 00:02, 10 July 2006 (UTC) I have created a seperate article Indian relativity. --Michael C. Price ^talk 06:03, 11 July 2006 (UTC)

Inertial

There is no record of the word "inertial" in Einstein's paper, "On the Electrodynamics of Moving Bodies." He specifically states:

"If we assume that the result proved for a polygonal line is also valid for a continuously curved line, we arrive at this result:".

Use of "inertial" constitutes original research, which is against wikipedia policy and a non - neutral POV. Der alte Hexenmeister 17:02, 11 July 2006 (UTC)

"Inertial" refers to what Einstein called "uniform rectilinear motion" in that article. It is not WP:OR since many other sources support the interpretation of "uniform rectilinear motion" as "inertial motion". Do note that these other sources are secondary sources, whose use is permitted under WP:OR. There is no need to stick to the original source exclusively. --EMS | Talk 17:13, 11 July 2006 (UTC)

So are you claiming that Einstein was self-contradictory? I'd have to agree that he was.

No matter, the word "inertial" does not appear in the paper and I have given an example of an instance where It is at once apparent that it is clear, in agreement with experience that we further assume Einstein did not mean "uniform rectilinear motion" in the literal text of his own words I quoted, regardless of second source opinions, don't WE?

The word "inertial" is yours or some other second source's research and violates WP:OR and WP:NPOV, since that is not relativity and wikipedia states that relativity refers to Einstein's relativity -- I would add the word "only" to Einstein's relativity. Relativity according to Schaefer is a violation of WP: OR. Please remove "inertial" from the article, and please do not vandalize wickipedia or I shall be compelled to raise an RfC and request that you be blocked from editting wikipedia. You are more familiar with the procedure than I, but I can learn and I thank you for teaching me.

Let me remind you the issue here is neutrality, not your free education. You only have to ask, I'm available on USEnet to provide you with corrections to your misunderstandings concerning the subject. Der alte Hexenmeister 22:47, 11 July 2006 (UTC)

---

"Symmetrical Relativity"

There's a new article called Symmetrical Relativity, which I assert is original research and hence unsuitable for Wikipedia. If you have a background in the subject your review and opinions would be welcome on the talk page. Thanks! --Craig Stuntz 17:16, 3 August 2006 (UTC)

E=(DELTA)MC?

Can someone who know the character map fix Einstein's numbers please its not E=mcQ I don't know who to do the 2 as a squarred to fix it.--Xiahou 00:39, 14 December 2006 (UTC)

Decision time

I would like some sense of whether people prefer the current version or this one. For myself, I am left to scratch my head a bit. I prefer to keep this article very short and "sweet": After all we have articles on special relativity and general relativity already. On the other hand, Dan Pelleg's enhancements are of the type and scale that are acceptable if an expansion is to occur. (I have regularly reverted explansions in the past that were nothing more that a cut-and-paste of the introductions [and sometimes more] of the main articles, but Dan's work is not of that ilk.)

I would like to empasaize that I am looking for feedback on the issues of scope, look & feel, and organization. I am much less concerned about the content. I know that Dan's text contains some misconceptions, but those are fixable. (In fact I have already tweaked the special relativity part, and will soon revise the general relativity part if a consensus to revert does not appear.) So the real issue is one of format and direction as opposed to being a content dispute. --EMS | Talk 04:39, 5 February 2007 (UTC)

Given the lack of comments, I am now building on Dan's work. --EMS | Talk 16:26, 6 February 2007 (UTC).

Illustrative rather than misleading

First - thank you for embracing my suggested change of structure for this article, my intention was to make it more accessible and palatable for non physicists (since all the more technical, specialized information can in any case be found in the main articles) and to tempt non physicists to learn more about this body of knowledge rather than deter them using terms that for many people are unclear.

As to the illustration "when inside a closed room that is free-falling, you can't distinguish between this state and the state of the room and you floating motionless (or without accelerating) in zero gravity":

Einstein himself wrote: "...it is impossible to discover by experiment whether a given system of coordinates is accelerated, or whether its motion is straight and uniform and the observed effects are due to a gravitational field." (The Fundaments of Theoretical Physics, 1940.) An equivalent statement is: it is impossible to discover by experiment whether a given system of coordinates is in straight and uniform motion not within a gravitational field, or whether its motion is accelerated as the result of a gravitational field (i.e. it is in free fall). Which, in so many words, is what my illustration says. Dan Pelleg 20:40, 25 February 2007 (UTC)

Free fall as inertia

Dan -

After [t]he upshot of this is that free fall is inertial motion, You want the article to include:

the meaning of this can be made tangible using this example: when inside a closed room that is free-falling, you can't distinguish between this state and the state of the room and you floating motionless (or without accelerating) in zero gravity.

The intent of the sentence is reasonable, but as written it really does not work. First of all, it creates the sense that free-fall and weightlessness are different things, but they are not (as you are aware). Secondly, it is not true that free-fall near the Earth is indistinguishable from being in far away in outer space due to tidal effects. (I will admit that this is a trivial point in some respects, but it is true.) Perhaps a sentence noting that objects in free fall are wieghtless may work, but I don't see what you wrote as clarifying the concept of free fall as inertial at all. Instead I see that as a long winded explanation that brings in additional concepts and does not lead the reader to the right place.

The main point of free fall as inertial motion is that objects in free fall are moving that way because they are not being acted on by any force. --EMS | Talk 21:28, 25 February 2007 (UTC)

Length contraction

I feel that the description of length contraction as it is now

Objects are shortened along the direction in which they are moving.

is a bit misleading. I made an edit to it

Objects appear shorter along the direction in which they are moving to an outside observer

which was reverted, no problem with that as I fear my edited version might be equally misleading :) I'm definitly not an expert in the field, but isn't it true that an observer travelling with the moving coordinate system would perceive objects standing "still" as length contracted, in which case we can't talk about length contraction without including the concept of an observer. Izbitzer 21:33, 23 April 2007 (UTC)

I did the revert and I have a number of objections to your wording. First of all, there is the "outside observer" business. This is improper because

1. This implies that the "observer" exists outside of spacetime, something that is physically impossible, and
2. This also implies that there is a prefered reference frame in which the rod has its full length. This goes against the principle of relativity and the fact the rod is at its full length for any local observer at rest with respect to the rod no matter how the rod is moving with respect to any other rod.

Perhaps "Objects are observed to be shortened in the direction that they are moving with respect to the observer" may be a better wording. What do you think? --EMS | Talk 21:49, 23 April 2007 (UTC)

That sounds good, thanks for the quick reply! Unfortunately, I wasn't as quick to reply again :) Izbitzer 23:18, 24 April 2007 (UTC)

I disagree, "are observed to be shortened" is a perfect grammatical equivalent of "appear shorter to an outside observer", and what it implies (except for a preferred reference frame) is that the shortening is merely an impression perceived by a consciousness, instead of a physical fact independent of the act of conscious observation (which is what it is - a physical fact independent of the act of conscious observation). In other words, it soothes our anxious intuition, reassuring us that the objects aren't really shortened, how absurd, they are only "observed" to be. Izbitzer, please explain why you found the previous description of length contraction, Objects are shortened along the direction in which they are moving, misleading. Thanks, Dan Pelleg 20:45, 10 July 2007 (UTC)

I only felt that it needed to be pointed out that the shortening isn't something that is exclusive to the "moving" reference frame. The reference frame in "rest" is also observed as shortened from the "moving" frame. I think this is a common misconception if you haven't studied relativity. I realise that the current wording might be a little hard to understand. I don't konw how it should be for everyone to be happy :) Izbitzer 10:15, 25 July 2007 (UTC)

Any phrasing that implies the shortening is an effect on the rod is misleading, since it suggests that the rod "feels" the contraction. Any phrasing that implies that it's shortened in the view of some observer is also misleading, since it suggests that length contraction can be seen.

Personally I think that length contraction is hugely overemphasized in introductory relativity courses. If I had my druthers, it'd be left out of the article (and the textbooks) entirely, or demoted to a footnote. Failing that, I'd prefer it be described as what it is, which is a coordinate effect. You need to set up a coordinate system (with at least two synchronized clocks) before you get length contraction, and that's important. Special relativity is not about coordinate systems—it's a symmetry constraint (Lorentz symmetry) on physical laws. -- BenRG 22:53, 25 July 2007 (UTC)

A strange experiment

Assume a given machine collapses to a certain state when it is subject to a magnetic field and we put a charge attached to it. Now if the machine is stationary no electromagnetic field is created by the charge and so the machine does not collapse but, if the machine with the charge is moved to higher and higher speeds, the stationary observer will eventually see the machine collapse because of the electromagnetic field created from his point of view, but an observer moving with the machine will keep on not experiment any magnetic field and so shall never see the machine collapse. Now we assume at a certain moment that the machine stops: will it have collapsed or not?
Fbartolom 14:28, 2 August 2007 (UTC)

Hi, this question does not belong on the talk page of a Wikipedia article - see WP:TALK.

A much more suitable place for this is (for instance) the Usenet newsgroup sci.physics.relativity.

DVdm 14:53, 2 August 2007 (UTC)

Please explain why a (mental) experiment that would contradict, if of course not explained, the present theory about reality and time would not belong to the discussions about relativity. Thanks for putting the paragraph at the end, I was not sure about were new articles should be put. Fbartolom 15:01, 2 August 2007 (UTC)

This talk page is for discussions about the article, not about the subject of the article. So this is definitely not a page for, like you say, "discussions about relativity". See WP:NOR and WP:TALK.

On this talk page you can propose a particular and preferably concrete change to the article itself, or you can of course use your personal talk page for this, or find someone else who is prepared to help you on his/her talk page, but an encyclopedia is really not the place for this. A much better place is sci.physics.relativity. Go ahead, try it.

Cheers, DVdm 16:08, 2 August 2007 (UTC)

Ok, I posted the message there too: as you correctly hint to, I thought the discussion page was about the theme of the article, not just the letter of it. Fbartolom 13:27, 3 August 2007 (UTC) (UTC)

Explaining Second Postulate of SR

For stationary observer and moving observer speed of blades of fan is same i.e 'c'. Both stationary and moving observer will measure one rotation of blade of fan in same time interval.

For stationary observer and moving observer, speed of particle travelling in coil of spring is same i.e. 'c'. Suppose that a straight spring is attached to bulb of torch and torch is stationary wrt observer. Suppose that photon is tracing path across coils of this spring. The observer will measure one spiral rotation of photon in time interval 't'.

Now suppose this source i.e torch is moving wrt observer and the straight spring attached to bulb of torch is also moving with torch. Even though the source(torch-spring) is moving wrt observer, still the observer will measure one spiral rotation in same time interval 't'.

To understand this in better way, begin from small speed. For example, a tenis ball rotating with speed 3.14 m/s in spiral hollow coil having diameter 1 meter.

The stationary and moving observer will measure same speed of tenis ball i.e 3.14 m/s in one spiral rotation.

It is to be noted that in two dimension, spring looks like transverse ~wave~.

This is explaination of second postulate of SR and not original research.

This is neo !!! 20:52, 23 September 2007 (UTC)

This is already explained in the main article, Special_relativity. Why would we need to put it here? If the user wanted more information about the postulates, they could look at the article I just referred to. --əˈnongahy ♫Look What I've Done!♫ 21:07, 23 September 2007 (UTC)

Viran: You ask me to explain what is unclear in your edit. Absolutely everything. Sorry, but I have no idea what you are talking about. Blades of what fan? Coil of what spring? You introduce a whole new concept, gravity spring, without defining it. In doing so, I believe, you are violating the Wiki policy against original research; please see WP:NOR. This is an encyclopedia and not a blog or discussion group. Relativity is an advanced topic, about which I think you should leave editing to the experts. One other thing: your threats mark you as someone not serious about the work of producing an encyclopedia cooperatively, and will only get you in trouble for disruptive behavior. No need to reply, as I am only passing through and will not be able to engage in further discussion here. Hertz1888 01:40, 24 September 2007 (UTC)

Like Hertz1888, I find your edit completely incomprehensible. If there's anything in it worth adding, it will need to be written by somebody else. As near as I can tell from your expansion above, you're talking about a fiber optic cable bent into the shape of a helix, in which light travels at c. You say that the time taken to complete one turn of the helix is the same with respect to any frame. That's incorrect. If the coordinate distance between turns is d and the coordinate time to complete a turn is t, then with respect to a boosted frame, the coordinate time per turn will be the time component of the Lorentz boost of (t,d,0,0). This can be larger or smaller than t. In the case of a rotating fan, d=0 in the rest frame, so with respect to any moving frame the rotation time is γt. -- BenRG 11:44, 24 September 2007 (UTC)

My advice to the editors of this page isto look at user talk:Viran. This editor at the start mistook Wikipedia for a discussion group, and still has not figured out what Wikipedia is not (for for that matter what Wikipedia is). For the moment, I am content to keep an eye on this character, but if he or she is persistent then some action will need to be taken to reign him or her in. --EMS | Talk 13:05, 24 September 2007 (UTC)

Put spring on table. Mark fixed points A and B on table. Velocity = frequency (number of coils between AB)*wavelength (distance between two coils of spring).

When the source of light is moving away, spring is stretched and wavelength increase. When source of light close in, spring is compressed and number of coils between AB i.e frequency increases and wavelength decreases. So whether source of light is stationary or moving velocity, of light remains same.

I can explain it further in details, but I will Not.

As I said to AGENT SMITH in MATRIX, I say the same thing to you all....

You can not scare me with this gestapo crap. I know my rights. I want my explainatory post in article.

This is neo !!! 14:58, 25 September 2007 (UTC)

Viran, please come back to your talk page. We really need to talk. Spryde 17:10, 25 September 2007 (UTC)

The term "relativity" coined by Max Plank or Henri Poincaré

The article states:

"The term "relativity" was coined by Max Planck in 1908 to emphasize how special relativity (and later, general relativity) uses the principle of relativity."

The actual term "relativity" was coined by Henri Poincaré in 1904 during a lecture at a mathematics conference in St. Louis. There is a footnote about this speech in the Wikipedia Poincaré article, under "references to work on relativity." Here's the footnote below:
"L'état actuel et l'avenir de la physique mathématique", Bulletin des sciences mathématiques 28(1904), 302-324 (Congress of Arts and Science, St. Louis, September 24, 1904)
I believe the article should read that Max Plank coined the term "Theory of Relativity" as opposed to just saying he coined the term "relativity," which I'm saying was actually coined by Poincaré four years earlier.
This is really more of a clarification of terms than an actual correction.
Jmiertschin 15:24, 26 October 2007 (UTC) jmiertschin - 10/26/07

Good point. I have made the correction. --EMS | Talk 16:11, 26 October 2007 (UTC)

I agree with Jmiertschin

The basic formalism to theory of relativity had been discovered by Poincaré and Lorentz in 1904, however Einstein was unaware of some of their previous work at the time of the publication of his first paper on relativity.

— Marion, J. B. & Thornton, Classical Dynamics of Particles & Systems, Chapter 14, p.507

I think it's better separate the theory of relativity from Einstein's special relativity theory and his general theory too. At least, some text explaining the origins of the theory.

-- Paulochf 201.83.20.239 (talk) 07:37, 22 March 2008 (UTC)

A-Class

Why is this article rated as A-class? Does it have an A-Class review? ṜέđṃάяķvюĨїήīṣŢ ^{Drop me a line}_{Review Me!} 15:28, 7 May 2008 (UTC)

Second Postulate - moved from article

I think Eienstein's second postulate is assumed to be postulate because we take light as a continuous wave motion. It can be explained if we think over it from quantum point of view. A quanta of enrgy leaving the source of light is like a bullet leaving the pistol. Once it has left the source it will move with a constant velocity without regard to the motion of the source. So there is no issue of the relativity of the source and light. There is no point in saying that there is an observor at source i.e. source as a frame of reference. So for as the observor is concerned it looks the source not the quanta exactly at the location quanta has left off. So the source is always ,differentialy , at rest. If we take antenna kind of view for the observor then relativity is an apparent phenomena for the observors not the exact measurement. So even if observor is moving with respect to the source it hardly affects its relativity with quanta which is disconnected from the source. So effectively we can say that any energy radiation is free from the laws of inertial or non-intertial 3D Cartesian coordinate frame of reference. It may carry meaning only in 4D Minkowski space. (Incorrect SineBot signature deleted - comment was not by Martin Hogbin (talk) 09:36, 24 November 2008 (UTC))

Proposing move to Law of Relativity

I belive it would be more accurate to call this the law of relativity now that it has been proven, feel free to comment Rankun (talk) 00:37, 24 November 2008 (UTC)

Are you referring to the constant speed of light? Martin Hogbin (talk) 09:37, 24 November 2008 (UTC)

No, some scientists proved it over the weekend, something with quarks gluons and energy + supercomputers. —Preceding unsigned comment added by 149.150.236.118 (talk) 17:19, 24 November 2008 (UTC)

There was a lattice QCD calculation that made the news recently. It's an important test of QCD, but not an important test of relativity, which reached the status of scientific law a very long time ago. We don't call it the "law of relativity" simply because physicists don't call it the "law of relativity". -- BenRG (talk) 19:37, 4 December 2008 (UTC)

Informal RfC for 'Speed of light' article

There is a dispute concerning the wording of the 'Light as electromagnetic radiation' section of the 'Speed of light' article. Editors are requested to give their opinions on the 'Speed of light' talk page. We decided to ask on related article talk pages rather than go for a full RfC so that we would get editors with a knowledge of and interest in the subject. Martin Hogbin (talk) 18:28, 6 February 2009 (UTC)

Special Relativity

I added an example to illustrate this principle. DanielGlazer (talk) 05:10, 9 June 2009 (UTC)

Motorcycle example of time dilation in special relativity doesn't seem right

My understanding is that in special relativity, two observers moving with respect to each other believe that each other's time is dilated; that is, each of them believes the other is aging more slowly. You can only get them both to agree that one is aging more slowly than the other by adding an acceleration, and you can only do that with general relativity, not special, right? I don't think the motorcycle illustration given for time dilation is correct as an example of special relativity... Jpietrzak (talk) 14:22, 25 September 2009 (UTC)

We can get them both to agree that one is aging more slowly than the other, by having a non-symmetric situation, which is the case here, as one is in an inertial frame whereas the other is not. Special relativity is perfectly capable of handling this kind of accelerated motion. General relavity is not needed to explain that. - DVdm (talk) 14:45, 25 September 2009 (UTC)

Ah, ok. I've not seen how accelerations work in special relativity before, but just a quick web search gives piles of examples. Still lots more for me to learn here... Thanks. Jpietrzak (talk) 16:23, 25 September 2009 (UTC)

Difference between the theory of special relativity and the theory of general relativity

Special relativity is the one which is understandably developed by the einstein in 1905 saying that the time variance with respect to the shift in the position of the particle and it is given as space time relation and the time variance is explained by the term time dilation.so studying of the space time is the special relativity.

Comming to the general relativity study of the mechanics of the photon is called the general relativity and it is obtained by the newtoniam mechanics and the relative and the relavastic nature of the particle involving the law of conservation and their mechanics like force(with a inertial frame of reference) and resultant velocity.so this relation talks behind the general theory of relativity.

dheeru498@yahoo.com —Preceding unsigned comment added by 117.195.233.155 (talk) 06:27, 13 November 2009 (UTC)

Law?

Wast the theory of relativity recently proven? doesnt that make it a LAW? —Preceding unsigned comment added by 68.121.84.218 (talk) 02:33, 8 April 2009 (UTC)

This isn't how science works. Laws are statements of fact, theories are explanations of facts.Triune (talk) 17:14, 13 April 2009 (UTC)

But the theory of relativity or better law of relativity is proven! So it has to be a law.--PaBraun (talk) 13:44, 12 June 2009 (UTC)

Gravity was proven by newton, until einstein proved otherwise. we generally leave theories as theories.Seeasea (talk) 17:58, 31 August 2009 (UTC)

If relativity is made scientific law this would supersede Newton's laws ( making them Newton's rules? ) maybe physicists are not ready to throw uncle issac under the bus just yet. OR MAYBE relativity has not been DIRECTLY observed. —Preceding unsigned comment added by 68.57.255.130 (talk) 03:12, 25 January 2010 (UTC)

Or * M A Y B E * you could take a course in physics, actually learn something, and stop speculating. Dan ☺ 07:30, 25 January 2010 (UTC)

Some people do not always agree with the initial assumptions that the theories are based on. I, for example, disagree with assumption (2),"The speed of light in a vacuum is the same for all observers, regardless of their relative motion or of the motion of the source of the light." I have a fair argument of why we might observe such a phenomenon as human observers but mistake what we witness for a new altered perspective of the electromagnetic spectrum. But if the Special Theory of Relativity is considered a certain 'fact', then those who consider it would surely have to ignore me upfront without a hearing. This doesn't mean we should keep things as mere theories. If we can find a superior grounding in reasoning that guarantees we are logically correct (ex:absolute fact: If you can read this, you can read this.)or you can induce a conclusion from samples of human reality that rely on completely enumerated premises that are themselves within the domain of the conclusion (like inducing that Natural Selection through Evolution is a fact, not merely a theory), then we should consider the theory as fact.--Scott Mayers (talk) 18:39, 8 May 2010 (UTC)

Scott, this is not the place for expounding your personal opinion on subjects. WP is based on established knowledge as shown in reliable sources.Martin Hogbin (talk) 21:53, 8 May 2010 (UTC)

biography

Albert Einstein was born in Ulm, in Wurttemberg, Germany, on March 14, 1879.Einstein died onApril 18, 1955 at Princeton, New Jersey.Albert Einstein married his cousin the same year he divorced his wife, Mileva Maric. —Preceding unsigned comment added by 24.90.186.233 (talk) 01:59, 21 December 2009 (UTC)

History

The theory of relativity, which has revolutionized the mathematical and physical concepts of modern times, is known to have been put forward by Albert Einstein early in the 20th century. However, we find that 1100 years before him Al-Kindi, a Muslim scientist and philosopher, had laid down the foundation of this theory. —Preceding unsigned comment added by Islamuslim (talk • contribs) 10:43, 22 March 2010 (UTC)

As these are not available online can you please quote the exact wording that you believe supports your assertion. Martin Hogbin (talk) 11:14, 22 March 2010 (UTC)

time dilation

Shouldn't we talk about time dilationm? Δt/$(1-v^{2}/c^{2})$^.5—Preceding unsigned comment added by Trtt (talk • contribs)

Not here. This is just an overview. Time dilation is handled in many of the articles to which links are provided. You'll find plenty over there. DVdm (talk) 08:44, 1 May 2010 (UTC)

American invention

I cannot believe how obtuse people can be. Einstein emigrated to the USA in 1933. He invented the concept of this theory. How is it therefore wrong to call the theory an American invention? Inventions are not always tangible objects, they encompass theories, concepts and original thoughts of all kinds. If the argument is that he wasn't an American when he created it, then why not change the category to "German inventions" instead of blanking it entirely. Burpelson AFB (talk) 21:51, 23 June 2010 (UTC)

So call it a Swiss invention then, he didn't move to the USA until 20 years after his third big paper (GR).

Besides which, it's an accepted truism amongst physicists that if you claim Einstein belongs to _any_ country, he will come and haunt you.

Your series of "Elbionan invention" categorizations seem to be remarkably unsuccessful, poorly thought out and downright inaccurate, even by the standardss of this infamously divisive and unhelpful categorization. I really hope you (and everyone) stops doing it. Andy Dingley (talk) 22:07, 23 June 2010 (UTC)

Wish with one hand and shit in the other, Andy. Remarkable! - Burpelson AFB (talk) 22:24, 23 June 2010 (UTC)

(ec)

Einstein created the theory long before 1933, so it cannot possible be an American invention. Shutz says that "Einstein invented relativity", so adding the category "Swiss inventions" would be appropriate for special relativity, whereas "Austrian and/or German inventions" would be appropriate for general relativity. Tricky. DVdm (talk) 22:09, 23 June 2010 (UTC)

That sounds entirely reasonable to me. Shall we add both categories "Swiss inventions" and "German inventions" to this? Or something else? Burpelson AFB (talk) 22:24, 23 June 2010 (UTC)

No, we shouldn't. Neither of those are appropriate without a source indicating that some nationality is important in the invention of relativity. Even then it's bound to be controversial, so the category should be left out. Relevant cited text can be included in the article, of course, subject to consensus. Andy Dingley is quite correct above. Burpelson AFB is running around like a headless chicken, sticking loads of unsourced, incorrect, and useless crap in this category crusade. Seriously, the assetions that dome is a Greek invention or rocket is a German invention are completely contradicted by the text of the articles. Hopefully, someone will rollback all this idiocy. Tim Shuba (talk) 22:37, 23 June 2010 (UTC)

(ec)

Centainly not "German inventions", since the very act of inventing general relativity took the better part of a decade. So perhaps the GR-bit earns the category "Swiss/Austrian/German inventions". If you ask me what we should do here, I would say, just leave it, as I find categorizing these theories as inventions, to be frank, a bit silly. But that's personal of course. Anyway, I think that a consensus will not be easily reached about this. You could try a little poll, just to sense the atmosphere. DVdm (talk) 22:42, 23 June 2010 (UTC)

I'd be right against categorizing it at all, for several reasons:

• It's Einstein. Pan-nationalist of them all.
• It's unhelpful. Does it matter?
• I don't know what "relativity" is. Are we talking SR or GR? Given that they're accepted as one person's conception, and we can't tie that person down to a single country, how can we tie two distinct concepts to a country? Wouldn't it also be just a little ridiculous to label that one person's work as somehow "belonging to" different countries?

The big significant concepts are rarely invented in one country. One instance of them appears in one place, then a better one appears elsewhere. Do we credit the concept, the first one that worked, or the one we all bought in the end? Look at television. Three different systems (Baird, Farnsworth, Blumlein) with almost nothing in common of their creative innovation except their overall name. This stuff never helps, it just starts arguments (Hungarian electrics anyone?) and it _MUST_ be cited perfectly if it's to be done at all. Andy Dingley (talk) 00:14, 24 June 2010 (UTC)

And why should they stop with national inventions? Why don't we also create "Male inventions", "Female inventions", "Morning inventions", "Afternoon inventions", "Atheist inventions", "Agnostic inventions"? Downright silly if you ask me.

Anyway, it seems moot now: See [7] and [8]. DVdm (talk) 07:57, 24 June 2010 (UTC)

So now discoveries are called inventions?! nonsense. —Preceding unsigned comment added by 201.165.158.77 (talk) 19:15, 15 January 2011 (UTC)

Metric expansion is not a consequence of relativity

All the vacuum solutions of general relativity without a cosmological constant contradict this claim. The most famous counterexample is probably the matter-filled Gödel universe, another exact solution to the Einstein field equations. While relativity is used to model metric expansion, the expansion does not follow from relativity, but requires various cosmological assumptions and observational data. Tim Shuba (talk) 16:57, 5 August 2010 (UTC)

Grolier source

I have opened a little thread at Wikipedia:Reliable sources/Noticeboard#gme.grolier.com to inquire about the Grolier source, which is used 13 times in the article.

Meanwhile, could someone who belongs to "institutions (schools, public libraries, colleges, etc.) and their authorized remote patrons" verify whether the most recent anon edit is indeed waranted by the cited source (http://gme.grolier.com/article?assetid=0244990-0)? Thanks - DVdm (talk) 10:50, 14 November 2010 (UTC)

Einstein's letter to the "Times"

This letter entitled “What is the theory of relativity?” [9] was written by Albert Einstein, and apparetnly printed in the London Times on November 28, 1919. It has content that appears to be useful to this article. I was going to add it to the external links - but we editors might be better served by using this as a source, and adding relevant material derived from it. -----Steve Quinn (talk) 20:09, 24 March 2011 (UTC)

That link is now broken. --79.8.76.162 (talk) 10:11, 24 September 2011 (UTC)

relativity

Can the mass of the body may be zero if the body is moved with the velocity of light according to the theory of relativity? —Preceding unsigned comment added by 113.199.142.1 (talk) 12:29, 29 September 2010 (UTC)

Particles such as photons acquire a mass equivalent , which allows them to be affected by gravitational fields. 1Z (talk) 12:15, 18 June 2012 (UTC)

Criticism

Please note, that there is already an article on Criticism of relativity theory (now referred to), so it's not appropriate to include specific non-mainstream papers here. --D.H (talk) 12:17, 12 February 2012 (UTC)

D.H, thanks for this edit. I didn't realize there was a whole article of Criticism of relativity theory to link to, or I would have done just what you did. --Uncle Ed (talk) 04:59, 13 February 2012 (UTC)

Would you be deaf and blind when you are faster than light

Deaf???

Well.....Its something indigestible to the so called commonsense...But one thing is surely there. commonsense is something which has been transformed throughout the history...Thats why the commonsense of post-Eisenstein era is something strange for the current commonsense definitions.

Ya.....so what I was just saying is you are a kind of deaf when you are travelling with your colleague In a super car (lets call it light that,for the time being)through air at a velocity greater than that of light. Imagine you said him"John,get me a hammer".But its sure that John would not hear you but he would here some completely different,Unpredictable set of voices.Because sound is of velocity 350 m/s while light is of 300000 m/s.So obviously by the time You Finish your sentence ,you would be somewhere lacks of kilometer apart from where you said it.And with its poor velocity sound cant trace the distance.But what you would here is the sounds existing at the point where you reach.But even then it doesn't makes any difference in the fact that you are virtually deaf...Because what you are going to undergo is a discontinuous set of sound pulse which would merge in your year in an uneven way that it would trouble your brain to distinguish them...Because even the voice existing in the place you reach cant exist in your ear for more than some nano seconds,since you are moving on with a velocity some thousand times greater than that of it.And it would make an overlapping of millions of sound waves in your ear and what you would be hearing would be a completely senseless conscious noise,which virtually makes you deaf.

Blind???

Yes..You would be virtually blind ,If you are trying to watch the planet which you have came from the back window of your spaceship of velocity much higher than that of light.Because after the event you leave the planet you stops watching the real existing planet.But you would see a pre image of the planet which existed sometime back.Because you see something when the light from thee illuminated object falls on your eyes.Here the interesting fact is that the current light ray from the planet is unable to trace you who is moving faster than you.So what falls on your eye is rays which have already reached at the point where you stay.But you wont feel any difference since light is continuously distributed throughout the way.And your vision of the planet ceases only after the point where the planet was illuminated for the first time.

So if the planet is destroyed at this instant ,you wont be able to witness it unless you stop your ship and wait for that ray to come to you.So what you actually see is tracking the history of the planet .The more you move away from it the more you goes into its history.and making you virtually blind of the ongoing present.

Rolling back!!!!!!!!!!!!!!

I am talking of all these ,since the time when we laughed at the ideas of something faster than light ,may be going to an end.The news of positive .Its definitely going to be the era of transformation in all physical laws of space time relations.May be it would be the time when we walk back to the history and see newton being true.Because it was because of Einsteins well accepted assumption that there cant be anything faster than light ,He could reject the Newtonian Physics.When we see something faster than light ,we would be forced to visualize the strong Newtonian invariant space where there may be much exciting things than even what we found!!!! — Preceding unsigned comment added by Rrejith (talk • contribs) 18:34, 8 April 2012 (UTC)

Details of experiments

Thanks to User:Braincricket for the valuable recent contributions, especially the experimental section. One comment: I think that the current description of the fundamental experiments is too detailed when we consider the fact, that we have separate articles for each experiment and an overview article on tests of special relativity. I think the technical details should be omitted in this article. --D.H (talk) 17:15, 1 September 2012 (UTC)

I was worried about that, too. Maybe one or two sentences describing each experimental setup would be appropriate? For this article, it's probably more important that we focus on the historical and theoretical significance of the experiments, rather than the nitty-gritty. Braincricket (talk) 19:23, 1 September 2012 (UTC)

I did some trimming just now. If you think the paragraphs on MM, KT, and IS can be condensed further, please go for it. Another way we could shorten the section would be to remove the paragraph about Maxwell and the aether. I think it's important that we mention the aether and the pre-Einstein paradigm somewhere, but the "Experimental Evidence" section might not be the best place. Braincricket (talk) 19:54, 1 September 2012 (UTC)

Fundamental question: Do you think it's appropriate to have a paragraph on each of those three experiments, or should we condense them all into one? Braincricket (talk) 20:03, 1 September 2012 (UTC)

I think the paragraphs are appropriate now, thanks. --D.H (talk) 21:35, 1 September 2012 (UTC)

Good luck, Braincricket! In the past, I've felt that this article needs a bold rewrite by either a single author or a couple of authors working closely together to give it a unity that it currently lacks. I've read your user page and see that you would like to bring this page up to GA status. I'll keep an eye on this page and may try to help out now and then. If you'd like some custom artwork, just ask and I'll see if I have time. D.H is an excellent person to be working with. Stigmatella aurantiaca (talk) 15:52, 2 September 2012 (UTC)

The thoery which ties in General Relativity With Special relativity

I believe Einstien had some secrets which we have just started to tap into. — Preceding unsigned comment added by Bobshull123 (talk • contribs) 00:11, 7 October 2012 (UTC)

The editor should make more substantial contributions to Wikipedia.
— Preceding unsigned comment added by 188.29.166.83 (talk) 12:55, 28 March 2014

   Every editor should sign their talk contributions.
   (By the way, i'll blow a little smoke into the wind by remarking that offering disparaging or anonymous advice to WP colleagues has some popularity among those who enjoy blowing smoke on a windy day.)
--Jerzy•t 00:31, 15 April 2014 (UTC)

   I am confident you are mistaken.
   Newton was big on keeping secrets, e.g. his alchemy, and keeping the calculus (and thus the terrestrial implications of his law of gravity) a secret, until there was danger of making it look like Newton had cribbed the whole of the calculus from Leibniz. (They each developed it pretty much from scratch, almost completely independently.)
   Einstein's professional character was completely different: he wouldn't say "oh, by the way, if you slam two decent sized chunks of heavy emitters of neutrons together hard enuf, you can blow up a whole city" to anyone but a few of his own professional peers (and to Roosevelt, eventually) -- but otherwise secret-keeping was against his nature.
--Jerzy•t 00:31, 15 April 2014 (UTC)

   Re the section title: You have to learn a little bit of math called tensor calculus -- and probably develop a lot of insight that most of us have no use for, in that area -- to fully grasp the fact that the "two" theories have exactly the relationship that their names are intended to describe: in any of the special situations where no acceleration occurs, the general theory and the special theory describe exactly the same effects. (And --tho this part is not implicit in the nomenclature, as i understand the preceding part to be, if the acceleration is small enuf, the error the special theory produces will be as small as you insist on. -- Hmmm, but quantum effects could make a liar out of me, if you are determined re that goal: I know very little about the quantum/relativity unification problem!)
--Jerzy•t 00:31 & 02:07, 15 April 2014 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Theory of relativity/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

This article can only be at most a thumbnail sketch of the two component theories, with the details left to the special relativity and general relativity articles. It is therefore given the "A" rating as a complete article that does what it needs to do. --EMS | Talk 04:53, 25 February 2007 (UTC)

Last edited at 04:53, 25 February 2007 (UTC). Substituted at 15:59, 1 May 2016 (UTC)