A question about the existance of a thread

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Discussion Overview

The discussion centers around the existence of threads related to the concept of the speed of light potentially slowing down, exploring both historical and contemporary perspectives on this idea. Participants also touch on the implications of varying speed of light theories and the challenges in finding relevant discussions within the forum.

Discussion Character

  • Exploratory
  • Debate/contested
  • Meta-discussion

Main Points Raised

  • One participant inquires about existing threads discussing the idea of the speed of light slowing down.
  • Another participant suggests that while there are theories proposing a different speed of light in the past, this does not necessarily imply that the speed of light is changing today.
  • A viewpoint is presented that varying the speed of light would require abandoning the principle of relativity, which is a significant concern for physicists.
  • Discussion of Joao Magueijo and John Moffat's varying speed of light theory, noting its controversial status and potential connections to creationist interests, though the participant expresses uncertainty about this relationship.
  • One participant critiques the responses for not directly answering the original question and suggests using the forum's search function.
  • Another participant shares their experience with the search function, indicating difficulties in finding relevant threads due to the volume of unrelated results.
  • A suggestion is made to use Google for more effective searching, specifically recommending exact-phrase searches to find relevant discussions.

Areas of Agreement / Disagreement

Participants express differing views on the implications of varying speed of light theories and the effectiveness of the forum's search function. There is no consensus on the existence of a specific thread addressing the original question.

Contextual Notes

Limitations include the ambiguity surrounding the search function's effectiveness and the varying interpretations of the implications of the speed of light theories. The discussion remains open-ended regarding the connections between varying speed of light theories and external interests.

Jimmy Snyder
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I know that my question is going to be misunderstood, but I am hoping that someone will read it for what it is and answer it directly:

Is there a thread in this forum that discusses the idea that the speed of light may be slowing down. If yes, can you direct me to that thread?
 
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My understanding is that there are suggestions that the speed of light may have been different in the past. This is not necessarily evidence that the speed of light is changing today though, and it is possible that the speed of light when measured in the past would have been precisely the speed of light as we measure it today anyway, even if today we see "the speed of light in the past" as being different.

(Basically that would be saying that no matter where or when you are, the speed of light is c.)
 
It's easy to conceptualize a varying speed of light. What makes the idea unattractive to physicists is that you have to abandon a very high symmetry principle called "the principle of relativity."
 
jimmysnyder,

Try looking for Joao Magueijo and John Moffat and VSL theory. It's apparently not part of the lunatic fringe per se, but equally it is not widely accepted either (consider the use of the words "controversial" and "dubious" by mainstream physicists to describe it).

Wikipedia has an article on it, but note that oddly enough one of the links at the bottom of that article is to "Creationists Interests". Is varying speed of light theory an attempt to reconcile the age of the universe to extremist Christian doctrine, is it being hijacked by such interests or had the author of the wikipedia article just noticed that creation scientists were taking an interest?

I don't know the answer, but I suggest care when reading articles in this area.
 
None of you all answered the original poster's question directly! :biggrin:

To the OP: Did you try the "Search" function listed in the navigation bar at the top of this page?
 
I tried "speed light slowing" but I got too many hits and none of the ones I looked at seemed to be on the topic. Unfortunately for this search, there have been experiments in which the speed of light in various media are quite slow and this topic has been visited a lot on these threads.
 
jimmysnyder said:
I tried "speed light slowing" but I got too many hits and none of the ones I looked at seemed to be on the topic.

Unfortunately, this site's search function doesn't seem to support searching on an exact phrase. However, Google does support exact-phrase searches, it indexes this site, and you can restrict searches to this site only. Try a Google search on the following:

"variable speed of light" site:www.physicsforums.com

The quotes tell Google that you want an exact match for that phrase. Also try some other similar phrases.
 

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