Wikipedia:Articles for deletion/Invariant speed


 * The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review).  No further edits should be made to this page.  

The result was no consensus, but it probably should be merged somewhere. Please note that "merge and delete" is not a valid outcome. — CharlotteWebb 03:05, 9 June 2007 (UTC)

Invariant speed
Merge or Delete. This article is really about the speed of light and should be merged into that article. As an independent topic it does not hold up. --EMS | Talk 16:04, 1 June 2007 (UTC)
 * Delete the article. Merge a condensed form into Special relativity; but that article is so exhaustive that there will be in fact little to merge. The concept of "invariant speed" is not an independent one in special relativity, it is directly tied to the speed of light. The article under discussion tries to use "invariant speed" as a link between special relativity and classical (non-relativistic) mechanics. This may be used in a textbook to explain the differences between classical and relativistic physics, or how to approach the classical limit. (That's a matter of taste, let's say.) But it's not much suited for a short introduction in an encyclopedia; even less does it warrant an own article. Wikipedia is not a textbook. --B. Wolterding 18:01, 1 June 2007 (UTC)
 * Redirect to speed of light, as the speed of light is the invariant speed. I don't believe this article contains any information that needs to be merged, and its existence is redundant.  Someguy1221 04:59, 4 June 2007 (UTC)
 * Keep and expand; if not keep then redirect to speed of light or Minkowski diagram. This article is about concept of speed independent of observer in general, while speed of light is only kind of special case, or more precisely, it is invariant speed in hypothetical universe with our laws of physics (one such universe is our own which is of course not hypothetical). Invariant speed is also an important property of spacetime. If Galilean transformations would be true, invariant speed would be infinite speed. Mathematical concept of invariant speed should be explained and it should be noted that speed of light is invariant speed. This should be done, among other reasons, because name "speed of light" can be sometimes misleading, making reader think that fact that velocities above c cannot be reached by means of constant proper acceleration is due to fact that light (in vacuum) propagates with speed c. Speed of light does not have "special place" in physics because it is velocity with which light propagates, but because it is more generally something that is most simple to call invariant speed. Name "speed of light" is only kept due to historical reasons so there should be both articles about speed of light and invariant speed.--antiXt 13:52, 4 June 2007 (UTC)
 * I entirely disagree, as mentioned above. But this is not the place to discuss physics problems. Provide multiple references that show that "invariant speed" is commonly used as an independent concept in the physics literature, and I will reconsider my vote. --B. Wolterding 15:17, 4 June 2007 (UTC)


 * This article needs a Complete Rewrite since it is both confused and confusing. The concept of an invariant speed other than light and of relativity without light is interesting, but this article is far from clear on the subject. A pertinent reference by one of my favorite physicists (David Mermin) is: "Relativity without light." Am. J. Phys., v.52, p.119.
 * Comment. There is perhaps enough material there to write a nice article on invariant speed, but Mermin himself states that the conventional viewpoint among physicists is that the speed of light is the invariant speed.  Further, while his paper is factually correct, he does not suggest that it is considered truly significant by anyone beyond himself and perhaps Purcell (although he does not explicitly state that).  Someguy1221 20:40, 5 June 2007 (UTC)
 * I agree that the conventional viewpoint among physicists is that the speed of light is the invariant speed. But it should be explained what invariant speed actually is, and which consequences arise from existence of finite invariant speed and what would be if some other case would be true. Also having an article about invariant speed in general could help to simplify some sentences in other articles (most of them are relativity-related) in the way of changing something like "Speed of light is universal constant and it is the speed that is independent of the observer, which implies (...)." into something like "Speed of light is invariant speed." --antiXt 19:03, 6 June 2007 (UTC)
 * Well, In light of this I change my mind to keep as a meaningful physical concept beyond simply being the speed of light. I will rewrite the article tonight when I have time.  Someguy1221 19:45, 6 June 2007 (UTC)
 * This does not convince me of anything. You will have gone from explaining the significance of the speed of light directly to instead refering someone the another article to figure out what an "invariant speed" is.  Maybe once I see the rewite I may be more charitable, but up until now I have seem the link to invariant speed in speed of light to be little more than internal spam for a very weak article. --EMS | Talk 21:02, 6 June 2007 (UTC)
 * And here I am beginning the rewrite when I realize the "relativity without light" bit is already explained in postulates of special relativity. I still believe that we should have an entry to immediately explain to readers what an "invariant speed" is should they come looking for it.  Yes, speed of light and special relativity have it in there, but the concept is independent of these, and you'd have to do some minor looking for it, so I think it should stay even if it's a permastub.  Someguy1221 05:37, 7 June 2007 (UTC)
 * IMO, the rewrite only serves to show how useless this articles is. Wikipedia is not an indiscriminate collector of information.  Wikipedia may not be paper, but there is no sense in having an entry here solely in order to have an entry here.  If there were multiple theories with different invariant speeds, then having this article could make sone sense.  Instead, the article is saying little more than that this notion is part of the postulates of special relativity.  The invariant speed is the speed of light, and no other qualifies.  Let's agree to either redirect or delete this article, and be done with it! --EMS | Talk 13:17, 7 June 2007 (UTC)
 * Comment. I'm the original author of this article, and I have to admit that (if I remember correctly) this was the first article I wrote on wikipedia.  I thought the concept of invariant speed was important enough to write about because it was important enough for Rindler (not strangely enough ladder paradox was my second article, also by Rindler).  Anyway, the point of invariant speed is that it's purely mathematical and the core of relativity is purely mathematical.  What links relativity to the physical is the invariant speed corresponding to the speed of light, the local/universal spacetime metric, and the definition of mass (classical or quantum).  If this article, in and of itself, is going to be excised, then I suggest Merging with invariant (physics).   DonQuixote 16:43, 7 June 2007 (UTC)
 * The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.