Wikipedia:Peer review/Speed of light/archive2

Speed of light[edit]

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The article has under gone substantial revision since the previous PR last year and the failed FAC earlier this year. Since the article will not pass FAC at the moment due to stability issue as the result of local WP:DRAMA caused by the activities of a now banned editor, it would be nice to get feedback from a broader audience in the meantime.

In particular, it would be good to have comments about accessibility from editors with a less technical background. From editors with a more technical background, it would be nice to have feedback on whether they think the article covers all bases and whether they think some aspects are given too much coverage. (See last thread on the talk page.)

Thanks a lot in advance,TimothyRias (talk) 12:09, 27 September 2010 (UTC)[reply]

Ruhrfisch comments: This is a very important topic so thanks for working on improving the article. I am somewhere in the middle on technical background, not a physics person, but know a fair amount about Physics. Anyway, here are some suggestions for improvement.

The external link checker in the tool box finds two dead links and two possible problem links.
I also wonder about some of the references used - one of the things checked at FAC will be the quality of reference sources, so what makes refractiveindex.info a WP:RS? Why not use some peer reviewed published source?
I also note that some refs appear to have incomplete information - for example access dates for internet refs, which need URL, title, author if known, and publisher. {{cite web}} and other cite templates may be helpful. See WP:CITE and WP:V
There is also at least unreliable source? tag that should be addressed before the next try at FAC
Be consistent on names. For example, Albert Einstein's full name is spelled out and linked in the lead, and then on next mention in the body of the article he is just referred to as Einstein, which is as the MOS suggests. However the third time he is mentioned he is Albert Einstein again, which is against the MOS (just Einstein is enough). Similarly, there are a fair number of people referred to by just their last names, i.e. Maxwell. I believe by the MOS these should be spelled out on first use (James Clerk Maxwell).
There are some places that still seem to need references - for example the whole thrid paragraph in Fundamental role in physics has no refs, and much of the second paragraph in the same section needs a ref (everything after Note 4).
Distance measurement - the whole section has no refs.
Second paragraph under Measurement is a direct quote, but has no ref.
WP:MOSIMAGES says to avoid sandwiching text between two images - on my monitor at least, there is such a sandwich in the Fundamental role in physics section.
I would also watch WP:OVERLINKing - most links appear once in the article lead and on first mention in the article body (plus refs and perhaps captions). James Clerk Maxwell and National Institute of Standards and Technology are each linked twice in the body of the article.
I am not a physicist, but I think the coverage of relativity is not too much. Given the importance of c for the development of relativity and vice versa, I am OK with the level of detail.
I wonder if the History section could come earlier in the article. Much of the Numerical value, notation and units section is historical. Some repetition might be avoided this way (not sure)
I also think this needs a copyedit - the prose seems OK, but as I read for comprehension, I also noted some typos like In the second half of the 19th century and the beginning of the 20th century several experiments were performed to try to detect this motion, the most famous of which is the experiment performed by Albert Michelson and Edward Morley in 1887.[118] the detected motion was always less than the observational error...

Hope this helps. If my comments are useful, please consider peer reviewing an article, especially one at Wikipedia:Peer review/backlog (which is how I found this article). I do not watch peer reviews, so if you have questions or comments, please contact me on my talk page. Yours, Ruhrfisch _><>°^° 21:11, 8 October 2010 (UTC)[reply]

Thanks for your comments. I've started addressing some of the issues you raised. (This may take awhile). About the history section, I'm not sure if having it earlier is such a good idea. This would delay discussing many of the more significant topics.TimothyRias (talk) 15:50, 13 October 2010 (UTC)[reply]

RJH comments: It looks to be in decent shape to me, with just a few entries tagged for issues. Here's a few remarks that I hope are of some use:

The lead has two separate instances where it mentions the types of particles that travel at the speed of light. This is somewhat redundant.
I'd like to see some mention of why the index of refraction is significant (beyond merely existing), both in the lead and in the "In a medium" section. (Yes I understand why. :)
"...limits the theoretical maximum speed of computers" appears to ignore both parallelism and possibly quantum computing. I think it should say "maximum speed at which computer components can communicate".
These should have a year specified: "more recent observations", "a new approach to tests". "Some authors use" is vague; it might be better to just say "sometimes c is used". These use unnecessary additive terms: "Also in the 11th century", "Another counter-intuitive consequence", "It also is generally assumed"
"it is normally impossible for any information or energy to travel faster than c". This doesn't clarify the terms of normality.
I think it would be worth stating somewhere that we don't currently understand why the speed of light has the value it has; that it just appears to be an inherent property of the vacuum.

Thanks.—RJH (talk) 21:11, 10 October 2010 (UTC)[reply]

I think the "standard" answer to the question why the speed of light has the value it has is that, since c is a dimensionful scale parameter of the theory, the question is meaningless unless we specify which units it is to be measured in, and even then the answer would tell us more about the units than about c itself (IOW a better question than why light is so fast is why we are so slow).[1] Anyway, I agree that that could be mentioned somewhere in the article. A. di M. (talk) 13:35, 11 October 2010 (UTC)[reply]

I understand that c is inextricably linked with the other properties of the universe, so my question then is whether c must have the value it has, or can it be scaled to possess different relative values in, say, other universes in the multiverse? But really I was just trying to look at the topic from a very basic perspective.—RJH (talk) 17:22, 12 October 2010 (UTC)[reply]

My view is that an universe with a different value of c but the same values for all dimensionless physical constants would be indistinguishable from ours, but I know there are different views (though I'm not sure I understand them). A. di M. (talk) 18:42, 12 October 2010 (UTC)[reply]