Is the Speed of Light Really Constant in a Vacuum?

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SUMMARY

The discussion centers on the concept of a "vacuum" in relation to the speed of light, specifically questioning whether a vacuum can be entirely devoid of electromagnetic waves. The participant argues that unless a vacuum is at absolute zero (-273 degrees C), it cannot be free from electromagnetic radiation due to black body radiation from surrounding materials. This raises doubts about the assertion that light can propagate through a vacuum, suggesting that the definition of vacuum does not imply the absence of electromagnetic waves.

PREREQUISITES
  • Understanding of the concept of a vacuum in physics
  • Knowledge of black body radiation principles
  • Familiarity with electromagnetic wave theory
  • Basic grasp of thermodynamics, particularly absolute zero
NEXT STEPS
  • Research the properties of a vacuum in quantum physics
  • Study the implications of black body radiation on electromagnetic wave propagation
  • Examine experimental evidence supporting the speed of light in a vacuum
  • Learn about the effects of temperature on electromagnetic wave behavior
USEFUL FOR

Physicists, students of physics, and anyone interested in the fundamental principles of light propagation and the nature of vacuums.

Pierre007080
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Speed of light in a "vaccuum"

My question is: What is this "vaccuum" vacant of? Unless the vacuum is at -273 degrees C it cannot be vacant of electromagnetic waves due to black body radiation from the material surrounding it. If this is true, then the statement that light can propagate through a vacuum has never been proven.
 
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"Vacuum" simply means no physical material, not that it is free of electromagnetic waves.
 

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