Is the speed of light affected by relative motion?

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Discussion Overview

The discussion revolves around the question of whether the speed of light is affected by relative motion, particularly in comparison to the addition of velocities in classical mechanics. Participants explore the implications of the theory of relativity on the speed of light and how it differs from everyday experiences with relative motion.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant questions why the speed of light does not follow the same addition principle as classical velocities, suggesting that if they move at a speed of c/2 opposite to a light beam, the light's velocity should appear to be 3v/2 or -3v/2.
  • Another participant references a similar question posed recently, implying that this is a common point of confusion.
  • A different participant asserts that the universe operates differently than the initial assumption, quoting Feynman to emphasize acceptance of the relativistic framework.
  • One participant provides a formula for velocity addition in relativity, suggesting that the law is indeed consistent but may not be intuitively understood by all. They encourage the use of the formula to compute the relative velocity of light.

Areas of Agreement / Disagreement

Participants express differing views on the application of classical velocity addition to the speed of light, with no consensus reached on the initial question. Some participants provide clarifications while others maintain their original queries.

Contextual Notes

The discussion includes references to specific velocities and the formula for relativistic velocity addition, but there is no resolution on the conceptual understanding of light's speed in relation to relative motion.

paras02
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Hello!
if a car(A) is moving with a speed 2m/s and another car(B) is moving in opposite direction with speed 3m/s. then velocity of car(A) with respect to (B) is 5 or -5m/s .
so my question is why the same principle does not follow with speed of light as according to theory of relativity speed of light remains same from every frame of refrence ?
or i can say that if i move with a speed c/2( c is the velocity of light ) opposite to the direction in which light is propagating the velocity of light w.r.t me will be 3v/2 or -3v/2.
Isn't this true?
 
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paras02 said:
why the same principle does not follow with speed of light

Simply put - that's not the way our universe works. Feynman said, "You don't like it? Go somewhere else!"
 
paras02 said:
Hello!
if a car(A) is moving with a speed 2m/s and another car(B) is moving in opposite direction with speed 3m/s. then velocity of car(A) with respect to (B) is 5 or -5m/s .
so my question is why the same principle does not follow with speed of light as according to theory of relativity speed of light remains same from every frame of refrence ?
or i can say that if i move with a speed c/2( c is the velocity of light ) opposite to the direction in which light is propagating the velocity of light w.r.t me will be 3v/2 or -3v/2.
Isn't this true?
Actually, the law is the same :smile:. It's only that you didn't know which is it:

V = (v1 + v2)/(1 + v1*v2/c2).

Now put 2m/s as v1 and 5m/s as v2 and compute V.
Then do the same with v1 or v2 or both, equal to c = 299,792,458 m/s.

--
lightarrow
 
thankyou guys
 

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