Relativity and the speed of light

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SUMMARY

The discussion centers on the principles of relativity and the constancy of the speed of light. Two observers, regardless of the motion of a boat, will perceive light simultaneously due to its invariant speed, which is always measured as constant. In contrast, sound waves, which require a medium, will reach observers at different times if the source is in motion. The conversation highlights the irrelevance of the ether concept in explaining light propagation, referencing the Michelson-Morley experiment as a pivotal study in this context.

PREREQUISITES
  • Understanding of basic physics concepts such as sound waves and light waves
  • Familiarity with the principles of relativity
  • Knowledge of the Michelson-Morley experiment
  • Concept of inertial frames in physics
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  • Research the Michelson-Morley experiment and its implications for the ether theory
  • Study the principles of special relativity and time dilation
  • Explore the differences between wave propagation in mediums (sound) versus vacuum (light)
  • Learn about inertial frames and their significance in physics
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Students of physics, educators, and anyone interested in understanding the fundamental concepts of relativity and the behavior of light and sound in different frames of reference.

mrcotton
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It is a general question just to boost my understanding
speedoflight_zps62f28a13.jpg


With a stationary boat both observers hear the horn at the same time as they are the same distance away from the horn.

In the bottom picture of the three pictures above:
If I make the boat move forward through the air at one block per time interval to the right, (the air is the medium the sound wave travels through). The observers are still the same distance away from the horn. The sound waves travel at two blocks per time interval in both directions.

So person 1 hears the sound in one time interval and person 2 hears the sound in 3 time intervals.

Is this above logic sound, (sorry)

speedoflight2_zps3877b0d0.jpg


But with light both observers see the light at the same time and record the same speed for the light wave as it has traveled the same distance to each in the same time interval.

Hope this all makes sense.
Is this logic so far correct.
Thanks
 
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Your explanation for the sound is coorect

mrcotton said:
But with light both observers see the light at the same time
Yes. The two observers and the source are all in the same inertial frame, so there is nothing special whether the boat is moving or not.

mrcotton said:
and record the same speed for the light wave as it has traveled the same distance to each in the same time interval.
They will always measure the same speed of light: it is the one thing that is constant for all observers.

And there is no such thing as the ether...
 
So this situation is ok for explaining that the light waves are not propagating through any medium. So no ether. I suppose I need to go off next and think about the Michelsom Morley experiment. If I understand correctly that experiment was set up to look for the ether. Thanks for your help Dr Claude
 

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