Speed of Laser on Spaceship Traveling at 0.5c?

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Discussion Overview

The discussion revolves around the behavior of a laser beam emitted from a spaceship traveling at half the speed of light (0.5c). It explores concepts from special relativity, particularly the constancy of the speed of light and the effects of relative motion on the observed properties of light.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions whether the speed of a laser on a spaceship traveling at 0.5c would be perceived as 1.5c.
  • Another participant asserts that the speed of light is always measured to be c, referencing the first postulate of special relativity.
  • It is noted that observers outside the spaceship would perceive the laser light as blue-shifted due to the relative motion of the spaceship.
  • A follow-up question seeks clarification on whether observers still see the speed of the laser as c, suggesting that only the wavelength changes from different perspectives.

Areas of Agreement / Disagreement

Participants express differing views on the implications of special relativity regarding the speed of light and its perception, indicating that the discussion remains unresolved with competing interpretations.

Contextual Notes

The discussion does not resolve the implications of relativistic effects on light and relies on the foundational principles of special relativity, which may not be fully articulated by all participants.

andytran
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i'm jux wondering would a laser mounted on a spaceship traveling at half the speed of light... wouldn't this make the speed of the laser on the ship change to 1.5c??

thx
 
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No. The speed of light is always locally measured to be c. This is the first postulate of special relativity.

- Warren
 
People who see the spaceship moving at 0.5 times the speed of light would see the laser at a different (blue shifted) color that the people on the spaceship.
 
but the observer still see the speed of the laser to be c.?
so the speed the stay the same, only the wavelength change according to the observer perspective??
 

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