Is the Speed of Light Truly Constant?

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Discussion Overview

The discussion centers on the nature of the speed of light, particularly whether it is a universal constant or varies depending on the medium through which it travels. Participants explore theoretical implications, practical observations, and related phenomena, including the behavior of light in different environments and its implications for cosmology.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants argue that light travels more slowly in media like air or glass, suggesting that the speed of light is not a universal constant.
  • Others assert that the universal constant refers specifically to the speed of light in a vacuum, which remains invariant.
  • One participant proposes that the perception of light slowing is due to absorption by the medium, rather than an actual change in the speed of light.
  • A participant introduces a speculative idea regarding the speed of light being faster in the early universe due to gravitational effects, linking it to inflation theory.
  • Another participant dismisses this speculative idea as nonsensical.
  • There are challenges to the coherence and correctness of some contributions, indicating contention over the clarity and validity of arguments presented.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the constancy of the speed of light, with no consensus reached on the implications of light traveling through different media or the speculative claims about its behavior in the early universe.

Contextual Notes

Some claims rely on assumptions about the behavior of light in various media and the interpretation of cosmological phenomena, which remain unresolved within the discussion.

avito009
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Light travels more slowly through light-transmitting substances such as air or glass, otherwise no lens would refract light. so does this mean that the speed of light is not a universal constant?
 
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Yes, the speed of light in various media is not a universal constant.
 
The universal constant is the speed of light in a vacuum
 
avito009 said:
Light travels more slowly through light-transmitting substances such as air or glass, otherwise no lens would refract light. so does this mean that the speed of light is not a universal constant?
The speed c is a universal constant. It is the only speed which is invariant, and it happens to also be the speed of light in vacuum as well as the speed of any other form of massless radiation. The speed of light in a medium is not equal to c.
 
The speed of light is not slowing. You can test this easyly with an prisma at the end. You will see that the ones that come first are less uv/blue (heat) than the ones later. Because the medium absorbes and be heaten. Between put water or glass. The glass or water will absorbe the first ones. How longer the distance in the medium, how slower it will look. That's why you get the idea that light slows. My idea. Blaim it on me
 
May i post here something about light? Because i got a general warning and i do'nt know what the post or not. But it is great knowledge to about light. I know a lot about the behavior of light to.

I had told climate change and the absorbation of sunlight. Particles in our atmosohere absorbe sunlight. So in automn is the sun more red (less/blue) because that light/radiation has to travel a longer distance in our atmosphere. The moon is more red near the horzon for this reason,

What i want to share is this and i think it's great, so does the light of an star. So dark matter and light etc;) if there were particles that absorbed light in our universum etc. I think that this is great to know.
 
Tahir, your responses are incoherent and wrong. The question was already answered in the first few responses.
 
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Question, is this true?

(13.8 billion years ago all the mass of the Universe was concentrated in a small area. Since time slows as we near mass then the speed of light would have been hundreds if not thousands of times faster than the speed of light today. This would explain the inflation theory.)
 
LitleBang said:
Question, is this true?

No. It's abject nonsense.
 
  • #10
On that note, I think it is time to put this thread out of its misery.
 

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