The Speed of Light: Comparing to What?

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Discussion Overview

The discussion revolves around the concept of the speed of light, specifically questioning the meaning of "compared to what" in relation to its measurement across different inertial frames. The scope includes theoretical aspects of physics and the principles of Special Relativity.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • One participant notes the speed of light is approximately 186,000 miles per second or exactly 299,792,458 meters per second, questioning the meaning of "compared to what."
  • Another participant asserts that the speed of light is the same in all inertial frames, suggesting that it does not depend on the observer's frame of reference.
  • A later reply confirms that light travels at speed c in any inertial frame, referencing the second postulate of Special Relativity.

Areas of Agreement / Disagreement

Participants generally agree on the constancy of the speed of light in all inertial frames, but there is some ambiguity regarding the initial question about comparison.

Contextual Notes

The discussion does not clarify the implications of the phrase "compared to what," leaving the interpretation open to further exploration.

mee
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the speed of light is 186000 mps or some such compared to what? :)
 
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Rephrase please. I'm not sure what you are asking.

Paden Roder
 
The speed of light is approximately 186,000 miles per secpnmd or exactly 299 792 458 metres per second. I don't know what you mean by 'compared to 'what', the speed of light is the same in all inertial frames.
 
Oops, sorry, didn't see your post there jcsd.

Paden Roder
 
jcsd said:
The speed of light is approximately 186,000 miles per secpnmd or exactly 299 792 458 metres per second. I don't know what you mean by 'compared to 'what', the speed of light is the same in all inertial frames.

So whatever inertial frame one is measuring by, light travels at c as if the inertial frame was still?
 
mee said:
So whatever inertial frame one is measuring by, light travels at c as if the inertial frame was still?
Yes. And that is the 2nd postulate of Special Relativity.
 

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