Talk:Special relativity/Archive 12

message: The article should start off by saying what special relativity actually is (cf. general relativity) before saying who formulated it. MP   (talk) 15:22, 18 June 2006 (UTC)
thread_title:  Introduction 

message: The new intro has as the last sentense of its first paragraph:
: Einstein's theory extends Galilean relativity to embrace both material objects such as people and nonmaterial forms of energy such as light.
This is totally incorrect and misleading.
# Classical mechanics could handle light as well as normal matter (although it did make some incorrect predictions).
# What makes SR different is the constancy of the speed of light for all observers.
I did an edit that reflected that .  I see that edit as being more correct since the constancy of c is a central postulate of SR instead of being a consequence.  Kindly explain why you saw fit to revert my edit. --EMS | Talk 17:10, 18 June 2006 (UTC)
replies: text: On second thought I now see that Harald managed to mangle my edit.  That may help to explain things, but the current statement is still unacceptable to me. --EMS | Talk 17:37, 18 June 2006 (UTC)
replies: text:  You must be hallucinating - at least that's my explanation, as I did not mangle that part. And I agree that your version is more correct than Anon's. Harald88 20:20, 18 June 2006 (UTC)
thread_title:  Nonmaterial energy? 

message: We must be very careful of the wording in this article as a simple word can break the whole concept of relativity.  I recently made a change to the sentence "...and returns to discover that his twin has aged much more rapidly." by removing the word "rapidly".  This misleads the reader to think that time was really passing faster for the twin on earth which breaks the concept of relativity.  The stationary twin's time didn't pass faster, only more of it passed. Tailpig 08:21, 3 July 2006 (UTC)
replies: text: Thanks for that improvement. "Time passing faster" is a meaningless concept: time always goes one second per second. —Keenan Pepper 14:14, 3 July 2006 (UTC)
thread_title:  Careful wording 

message: I believe the second postulate should read:
There is an upper limit to the speed of interaction between two physical objects which is constant throughout space and time. This maximum speed is in fact equal to the speed of light in a vacuum.
From the first postulate, it can be then concluded that this maximum speed is the same in all inertial reference frames.
I think as it stands, the second postulate is not sufficient. I'm not sure, but I don't believe that simply saying the speed of light is a constant in all reference frames is enough to imply that the maximum speed of interaction is equal to the speed of light in all reference frames, which needs to be stated somehow either as a postulate or as a derivation. PAR 17:23, 11 July 2006 (UTC)
replies: text: There have in the not too distant past been extensive discussions on how exactly the second postulate should be worded.  Many or most of it is archived, though some is on top of the page.  You might want to skim some of that for an idea of what on earth we were all thinking at the time.  If I remember correctly, the current wording was something of a compromise.  Just a heads up, or a warning to keep your head down, as the case may turn out to be...  ;) :D  DAG 18:07, 11 July 2006 (UTC)
replies: text:  Einstein did not postulate a maximum.  He postulated that there is a speed c (the speed of light) which is the same is all inertial frames of reference.  That this constant speed is a maximum is a consequence of the theory. --EMS | Talk 19:21, 11 July 2006 (UTC)

text: Nowadays it's becoming popular to postulate a possible limit speed; if that speed is infinity we would get "Galilean relativity", but it was experimentally found that that speed is c. Any of such approaches is sufficient. The second postulate isn't like a commandment. ;-) Harald88 20:26, 11 July 2006 (UTC)
thread_title:  The second postulate 

message: To:  Wikipedia
<http://en.wikipedia.org>
28 July 2006
From: Gerald L. O'Barr   <globarr@yahoo.com> 
6441 Dennison St.    (858) 453-0071
San Diego, CA 92122 
The following thoughts should appear in any 
subject where Special Relativity is being presented:
----
As far as it is presently known, it is 
mathematically impossible for any test to 
differentiate between the 4-D of Special Relativity 
(SR) and a reality of simple 3-D where there are 
changes in lengths of rulers and in the rates of 
clocks, as was assumed by Lorentz.  Thus, the 
assumption that there is 4-D cannot yet be 
scientifically supported.  It is therefore 
unscientific to accept 4-D over a simpler 3-D 
approach, unless or until a test can be made that 
would properly discriminate between these two 
approaches, and in which support for 4-D was 
unambiguously shown.    
The study of SR by using 4-D math is acceptable, 
since it is a very powerful and effective way to 
solve the math that needs to be solved.  But at no 
time should any interpretation be made that this 
supports 4-D, since it does not.  Math problems can 
often be solved by using a number of dimensions 
greater than what is actually involved.  It only 
takes an appropriate number of zeros and/or other 
inter-relationships to accomplish such actions.   
The use of a simple 3-D approach removes all 
apparent paradoxes.  In other words, most of the odd 
things that appear to occur in SR are mainly the 
effects of having measurement tools that change in 
their lengths or rates, and not due to anything odd 
with the actual physics.  
Thanks for reading!
-- Gerald L. O'Barr
:Um, even classical mechanics has four dimensions. It's obvious there are four dimensions because you need four coordinates to specify where and when an event takes place; for example, latitude, longitude, altitude, and time. Being in the right place at the wrong time is just as bad as being in the wrong place at the right time.
:You say "The following thoughts should appear in any subject where Special Relativity is being presented", but that is not true, they're only your thoughts, and they're not notable enough to appear in an encyclopedia article. Publish a paper in a peer-reviewed journal and then maybe we'll mention it. —Keenan Pepper 21:05, 29 July 2006 (UTC)
replies: text: Pardon? I didn't say I couldn't understand you, I said your thoughts don't belong in the encyclopedia article, because they're original research and not verifiable. Many experiments have confirmed the predictions of SR with great accuracy: Hafele-Keating experiment, Ives-Stilwell experiment, Kennedy-Thorndike experiment... —Keenan Pepper 22:21, 29 July 2006 (UTC)

text: Okay, now we're getting somewhere. You're right, every theory has weaknesses that should be presented, but this article does present them. There is a section Special relativity#Status that links to an entire article Status of special relativity devoted to the subject. Does that satisfy you? You are welcome to add any criticisms or shortcomings that are missing, as long as your additions follow the Wikipedia policies of notability, verifiability, etc. —Keenan Pepper 00:04, 30 July 2006 (UTC)
replies: text: May I ask Gerald - can you give a hypothetical example of what a test might be that would answer the question of whether we are dealing with a 3-dimensional space or a 4-dimensional space? PAR 00:38, 30 July 2006 (UTC)
thread_title:  4-D is not able to be scientifically established.