Talk:Kennedy–Thorndike experiment

Illustrations

D.H - Thanks for expanding on what I wrote. I had left things a bit like the famous Sydney Harris cartoon.

If you need any translated versions of my illustrations for the German Wikipedia, just give me the appropriate translations for any labels. I can relabel the figures and upload them to my Google Docs account for you to use. Stigmatella aurantiaca (talk) 12:12, 25 July 2012 (UTC)

I think I can edit the svg images by myself with inkscape, then I will upload them on commons. Thanks again for expanding and illustrating this article! PS: Is there a specific reason why you use both "cc-by-sa-3.0" and "GFDL-self"? Shouldn't the first alone be sufficient?--D.H (talk) 14:35, 25 July 2012 (UTC)

Just habit, I guess.

Always be sure to convert any text to paths. There is a nasty librsvg bug that can give you immense grief if you don't. See Wikipedia:SVG Help. A special SVG validator specific for Wikipedia is available that will catch most but not all rendering bugs before you upload. I'll find the link for you. Before I knew of these tools, you'll find a lot of my early work converted to PNG. Stigmatella aurantiaca (talk) 17:28, 25 July 2012 (UTC)

The first image I ever created was this one: File:Myxobacterial msDNA.svg which I converted to PNG for Multicopy single-stranded DNA which I had a special interest in. Stigmatella aurantiaca (talk) 17:49, 25 July 2012 (UTC)

I've included both images in de:Kennedy-Thorndike-Experiment. --D.H (talk) 17:59, 25 July 2012 (UTC)

It's interesting that the gray background shows through. I wonder if I can manage a workaround? I've had experience with a similar problem with Template:Multiple image on Michelson-Morley experiment. For that, I substituted a PNG for the top image, but there ought to be a way to keep the SVG.

One reason why I don't upload directly to Commons is that rendered images sometimes get cached for a long time. So if I decide that I need to alter a figure, it may be many days before the old cached rendering gets replaced with a new image. That can be very annoying. Stigmatella aurantiaca (talk) 18:44, 25 July 2012 (UTC)

Grey background is standard in de.wikipedia .... don't know why. --D.H (talk) 19:20, 25 July 2012 (UTC)

For each image I added a new layer below the main layer, and locked the main layer to prevent accidents. Switching to the lower layer, I added a borderless rectangle and sized it to exactly match the width and height of the image, then changed its fill color to white. I'm sure there must be an easier alternative than an SVG expert could point out to me, but meanwhile, this kludge worked. Stigmatella aurantiaca (talk) 00:52, 26 July 2012 (UTC)

The SVG Check tool is what I was referring to earlier. It's not perfect, but imperfect is better than no check at all. Stigmatella aurantiaca (talk) 01:07, 26 July 2012 (UTC)

If you ever experience a problem with the cache not updating, here is a quote of what I just learned on Wikipedia talk:SVG Help:

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To AnonMoos – From the client side, how do you signal the Wikimedia server or any other servers along the way to "purge" their images? I've sometimes waited for over a week for "the" cache to clear. All I know for sure is that it's not my client-side. Stigmatella aurantiaca (talk) 07:26, 26 July 2012 (UTC)

If you go to directly to the Wikimedia Commons image description page, on most skins there should be a "purge" link or tab, or you can add "&action=purge" / "?action=purge" (depending on context) to the URL... AnonMoos (talk) 16:58, 26 July 2012 (UTC)

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Added highly simplified figure of Braxmaier et al., leaving out the electro-optic and acoustic modulators, etc. necessry for the modulation transfer spectroscopy technique to actually work. If you think that is over-simplifying things, I can add them back in, but I think the majority of Wikipedia users wouldn't have much use for that level of detail. Stigmatella aurantiaca (talk) 16:53, 29 July 2012 (UTC)

Great work again, thanks! --D.H (talk) 18:22, 29 July 2012 (UTC)

The KT experiment is not a test of Special Relativity

The velocity between the experimenters and their experiment is always zero. Hence Special Relativity does not enter in to the experiment. Thus the experiment is totally mis-described.RFNo (talk) 13:02, 16 October 2013 (UTC) I have had no reply to my criticism so will modify the article if not challenged within 7 days.RFNo (talk) 11:11, 21 October 2013 (UTC)

You were originally not considered worth replying to, but now that you have announced your intention to add your original research to this article, I assure you that every modification you make that is not backed up by a reliable source will be reverted. You exhibit a total lack of understanding of this experiment and of special relativity in general. Original research contributions will not be tolerated. Please follow the links to discover what constitutes a "reliable source" and Wikipedia policy on "original research". Stigmatella aurantiaca (talk) 11:36, 21 October 2013 (UTC)

The reliable source that is behind my comment is Einstein's Special Theory of Relativity. An impeccable source I hope you agree. Are you denying that there was no relative velocity between the observer (the experimenter) and the observed body (the experiment). If you apply relativity where there is no relative velocity you cant expect relativity effects to occur. And please cut out the insults. If you will not accept my comments then I must ask the Relativity committee to consider them. RFNo (talk) 19:06, 21 October 2013 (UTC)

"Research that consists of collecting and organizing material from existing sources within the provisions of this and other content policies is fundamental to writing an encyclopedia. Best practice is to research the most reliable sources on the topic and summarize what they say in your own words, with each statement in the article attributable to a source that makes that statement explicitly. Source material should be carefully summarized or rephrased without changing its meaning or implication. Take care not to go beyond what is expressed in the sources, or to use them in ways inconsistent with the intention of the source, such as using material out of context. In short, stick to the sources." Stigmatella aurantiaca (talk) 23:23, 21 October 2013 (UTC)

@RFNo. As explained in plenty of sources (some of them given in the article), the Kennedy-Thorndike experiment is one of the fundamental experiments of special relativity. It tests the isotropy of the speed of light with respect to the motion of a hypothetical preferred reference frame (as Michelson-Morley), and more importantly the influence of different velocities of the Earth-bound apparatus on the speed of light during Earth's orbit around the sun. In other words: The "observer" is the KT-apparatus, and the "observed object in relative motion" is the "preferred reference frame" or "aether". Therefore such isotropy experiments are also called "aether drift experiments". In order to avoid any measured aether drift in KT-experiments, a combination of length contraction and time dilation due to the relative motion between Earth and the hypothetical "preferred frame" must be assumed. All of this is explained in plenty of sources, analyzing both Michelson-Morley and Kennedy-Thorndike experiments. Your personal opinion whether this is right or wrong is not relevant. --D.H (talk) 07:52, 22 October 2013 (UTC)

I am perfectly aware of all you have described above. But you are in a complete muddle here. The concept of the Aether is incompatible with Special Relativity. It is most novel and brave of the author of this article to employ Aether physics to explain the experiment result. But at the same time he cannot claim that it is a test of Special Relativity. Furthermore I do not know of a recognized source which predicts length contraction and time dilation as a consequence and as a function of Aether velocity and which is derived directly from the properties of the Aether. There are such sources but I do not think they are recognised as being acceptable. The hypothesis of the Aether is denied by modern physics.RFNo (talk) 10:56, 22 October 2013 (UTC)

Let me add this. I applaud both the bravery of the author and his Aether explanation of the experiment. But it is nothing to do with Special Relativity. If this article is the beginning of a return to the Aether and to Aether physics I am all for it.RFNo (talk) 11:10, 22 October 2013 (UTC)

Special relativity relies on the assumption that all frames of reference are equal, or in other words, that no preferred inertial frame exists. Therefore any refutation of such a preferred frame (or "aether") is a confirmation of special relativity and the isotropy of the speed of light ("Aether wind" is a simplified historical name for violations of the isotropy of the speed of light). See the papers by Robertson or Mansouri-Sexl (they are linked in the article) where the connection of length contraction and time dilation is discussed, in order to make all inertial frames equal in accordance with the relativity principle (connecting the experiments of Michelson-Morley, Kennedy-Thorndike, and Ives-Stilwell). --D.H (talk) 12:27, 22 October 2013 (UTC)

You are misreading the article if you believe that it supports an aether explanation. No set of experiments can disprove an aether, but for an aether to be consistent with the range of experiments that have been performed, it must possess a bizarre range of completely ad hoc properties. Special relativity is vastly preferred over aether theories because SR arrives at its conclusions starting with a completely natural set of assumptions. Modern derivations of special relativity do not even require the second postulate.

Starting with the first postulate alone, along with basic assumptions known to be required of any physical theory (e.g. a self-consistent set of transforms must form a group, etc.), one finds that there are only three theories compatible with the first postulate, the (four-dimensional) Euclidean, Galilei, and Poincare groups. Only one of these theories agrees with observations and experiment.

As D.H has explained, the KT experiment is one of the core experiments supporting special relativity, since it shows that length contraction alone provides an insufficient explanation for the observed experimental results. Stigmatella aurantiaca (talk) 13:04, 22 October 2013 (UTC)

In addition, WP policies have already been explained to @RFNo here:

Talk:Twin_paradox#New_preliminary_section.

Any discussion based on original research cannot improve the article. --D.H (talk) 13:38, 22 October 2013 (UTC)

Ihe conclusions that the author reaches are unwarranted.

Applying Special Relativity gives a zero relative velocity between the observer (the experimenter) and the observed body (the experiment). Thus no relative velocity effects are predicted and were not observed. A null result for zero relative velocity cannot be proof of Special Relativity as you claim. Aether physics looks at the KT experiment differently. It assumes the experiment is moving through the Aether but that length contraction and time dilation (as functions of Aether velocity) operate such that they give the observed null result. Thus two different and incompatible theories both predict the same result. It is not possible that the operation of Aether physics goes any way to proving Special Relativity or indeed any other theory. The author of this article is in a total muddle.